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New functions in .NET 2.0 ???

P: n/a
Hi All:

I have this line of code, but the syntax check in VB.NET 2003 and also in
VB.NET 2005 Beta 2 shows as unknown:

Dim local4 As Byte

Fixed(local4 = AddressOf dest(offset))

CType(local4, Short) = CType(src, Short)

Return

End Fixed

What is the "FIXED and END FIXED" and how the syntax error can be "fixed"
???

Thx,

Federico
Jul 22 '05 #1
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7 Replies


P: n/a
That looks like code that was generated by Reflector. I saw the Fixed
and End Fixed code keywords in Reflector for some code. They don't
exist in VB as far as I know.

Jul 22 '05 #2

P: n/a
Frederico-

If I had to guess, FIXED is some sort of internal notation for "Using",
a new VB.NET 2.0 keyword. You can learn more about the Using keyword here:
http://pluralsight.com/blogs/fritz/a...4/28/7834.aspx

Regards-
Eric

www.codedaily.com

"Federico G. Babelis" wrote:
Hi All:

I have this line of code, but the syntax check in VB.NET 2003 and also in
VB.NET 2005 Beta 2 shows as unknown:

Dim local4 As Byte

Fixed(local4 = AddressOf dest(offset))

CType(local4, Short) = CType(src, Short)

Return

End Fixed

What is the "FIXED and END FIXED" and how the syntax error can be "fixed"
???

Thx,

Federico

Jul 22 '05 #3

P: n/a
..NET does not support alphanumeric sort of arrays. (I hope that changes
soon!) Meanwhile, here is a solution.

You could use this in your listbox by sorting the items in an array and then
adding the array items from 0 to length to your listbox.

1. Create a custom comparer class that implements IComparer:
using System;
using System.IO;

namespace Test1CSharp
{
/// <summary>
/// Lacey Orr
/// 29 June 2005
/// Alpha-numeric sorting solution.
/// </summary>

public class AlphaNumCompare : System.Collections.IComparer
{
public int Compare(Object a1, Object b1)
{
//In my case, I compared Directory objects. So I took out
// the filenames / foldernames from the parameter
objects and
// passed those to the sort.

//The string variables to compare
string a = "";
string b = "";

//Is a1 a FileInfo?
if (a1.GetType() == System.Type.GetType("FileInfo"))
a = ((FileInfo)a1).Name;
else
a = a1.ToString();

//Is b1 a FileInfo?
if (b1.GetType() == System.Type.GetType("FileInfo"))
b = ((FileInfo)b1).Name;
else
b = b1.ToString();

return CompareAlphaNum(a, b);
}

// CompareAlphaNum: Does an alphabetic sort.
private static int CompareAlphaNum (string a, string b)
{
//Do a quick check for empty strings. If one string
is empty, then we
// can get out without doing any work.

if (a.Length == 0 && b.Length > 0)
return -1;
else if (a.Length > 0 && b.Length == 0)
return 1;
else if (a.Length == 0 && b.Length == 0)
return 0;

//The order of chars - make this however you want.
string strNums = "0123456789";
string strSortOrder = "
..!#$%&'()*+,-/:;<=>?@[]ˆ_{}~0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefgh ijklmnopqrstuvwxyz";

//Variables for comparing
bool aSmaller = true;
bool isFound = false;
int intIndex = 0;
// intLength determines the number of times to loop.
We will loop
// until we hit the end of the shorter string - a
or b.
int intLength = (a.Length < b.Length? a.Length:
b.Length);
string strNumA = "";
string strNumB = "";
int numA = 0;
int numB = 0;
int j = 0;
int k = 0;

//Do the compare while we are not at the end of
either string and haven't found
// the result.
while (!isFound && intIndex < intLength)
{
// if we are dealing with numbers, then sort
the numbers numerically
if (strNums.IndexOf(a[intIndex]) > -1 &&
strNums.IndexOf(b[intIndex]) > -1)
{
//Get all the numbers in string A until
we hit a non-number
j = intIndex;
while (j < a.Length &&
strNums.IndexOf(a[j]) > -1)
{
strNumA += a[j].ToString();
j++;
}
//Get all the numbers in string B until
we hit a non-number
k = intIndex;
while (k < b.Length &&
strNums.IndexOf(b[k]) > -1)
{
strNumB += b[k].ToString();
k++;
}

numA = Convert.ToInt32(strNumA);
numB = Convert.ToInt32(strNumB);

if (numA < numB) // a is before b in
sort order; a < b
return -1;
else if (numA > numB) // b is before a
in sort order; a > b
return 1;
else if (numA == numB)
{
//The numbers are the same.
Remove the number part from the strings
// and compare the remainder of
the string.
return
CompareAlphaNum(a.Substring(strNumA.Length, a.Length-strNumA.Length),
b.Substring(strNumB.Length, b.Length-strNumB.Length));
}
}
else
{
if (strSortOrder.IndexOf(b[intIndex]) <
strSortOrder.IndexOf(a[intIndex]))
{
// If string a < b in a sort, then
we're done
aSmaller = false;
isFound = true;
}
else if
(strSortOrder.IndexOf(b[intIndex]) > strSortOrder.IndexOf(a[intIndex]))
{
// If string a > b in a sort, then
we're done
aSmaller = true;
isFound = true;
}
else if (( b.Length < a.Length) &&
(intIndex == intLength - 1))
{
// If the strings are equal up to
the length-th char but a is longer,
// then we're done.
aSmaller = false;
isFound = true;
}
else
{
// Otherwise, keep sorting
intIndex ++;
}
}
}

if ((a.Length == b.Length) && !isFound)
return 0; //strings are the same.
else if (aSmaller)
return -1; // a is before b in sort order; a < b
else
return 1; // b is before a in sort order; ; a
b }
}
}
2. Use the custom class using Array.Sort(myArray, new MyCompareClass()).

a. Add a new web page

b. Add:
using System.IO;
using System.Text;

c. Add a label to the form (lblDir) to display the sort

d. In the page load:

private void Page_Load(object sender, System.EventArgs e)
{
//Get files in dir
String strDir = MapPath("~/./");
DirectoryInfo curDir = new DirectoryInfo(strDir);
FileInfo [] fiArray = curDir.GetFiles();
string [] strFilenames = new string[fiArray.Length];
for (int j = 0; j < fiArray.Length; j++)
{
strFilenames[j] = fiArray[j].Name;
}

// Sort files
Array.Sort(strFilenames, new AlphaNumCompare());

//Display files
StringBuilder sbFiles = new StringBuilder();
for (int k = 0; k < strFilenames.Length; k++)
{
sbFiles.Append(strFilenames[k] + "<BR>");
}
lblDir.Text = sbFiles.ToString();
}

Lacey

"Federico G. Babelis" wrote:
Hi All:

I have this line of code, but the syntax check in VB.NET 2003 and also in
VB.NET 2005 Beta 2 shows as unknown:

Dim local4 As Byte

Fixed(local4 = AddressOf dest(offset))

CType(local4, Short) = CType(src, Short)

Return

End Fixed

What is the "FIXED and END FIXED" and how the syntax error can be "fixed"
???

Thx,

Federico

Jul 22 '05 #4

P: n/a
Fascinating.

You make the following statement:
.NET does not support alphanumeric sort of arrays.
This is simply not true. For your example, you simply have to implement
IComparable for your complex type, you don't need to implement a string
comparison. That is built in.

In other words, you could replace the line: return CompareAlphaNum(a, b);
with
return a.CompareTo(b);

and delete the entire "CompareAlphaNum" routine.
Note that the CompareAlphaNum routine below doesn't use the same collation
order that .Net uses. Perhaps you meant that .Net doesn't sort a capital
'Z' in front of a lowercase 'a'. If that is what you meant, you are right.
However, it is patently false to say that .Net doesn't support alphanumeric
sorting.

Some reference articles for you to read:
http://msdn.microsoft.com/library/en...sorttopic3.asp
http://odetocode.com/Articles/203.aspx
http://www.devx.com/dotnet/Article/21089
http://aspnet.4guysfromrolla.com/articles/060403-1.aspx

--
--- Nick Malik [Microsoft]
MCSD, CFPS, Certified Scrummaster
http://blogs.msdn.com/nickmalik

Disclaimer: Opinions expressed in this forum are my own, and not
representative of my employer.
I do not answer questions on behalf of my employer. I'm just a
programmer helping programmers.
--
"Lacey" <La***@discussions.microsoft.com> wrote in message
news:11**********************************@microsof t.com... .NET does not support alphanumeric sort of arrays. (I hope that changes
soon!) Meanwhile, here is a solution.

You could use this in your listbox by sorting the items in an array and
then
adding the array items from 0 to length to your listbox.

1. Create a custom comparer class that implements IComparer:
using System;
using System.IO;

namespace Test1CSharp
{
/// <summary>
/// Lacey Orr
/// 29 June 2005
/// Alpha-numeric sorting solution.
/// </summary>

public class AlphaNumCompare : System.Collections.IComparer
{
public int Compare(Object a1, Object b1)
{
//In my case, I compared Directory objects. So I took
out
// the filenames / foldernames from the parameter
objects and
// passed those to the sort.

//The string variables to compare
string a = "";
string b = "";

//Is a1 a FileInfo?
if (a1.GetType() == System.Type.GetType("FileInfo"))
a = ((FileInfo)a1).Name;
else
a = a1.ToString();

//Is b1 a FileInfo?
if (b1.GetType() == System.Type.GetType("FileInfo"))
b = ((FileInfo)b1).Name;
else
b = b1.ToString();

return CompareAlphaNum(a, b);
}

// CompareAlphaNum: Does an alphabetic sort.
private static int CompareAlphaNum (string a, string b)
{
//Do a quick check for empty strings. If one
string
is empty, then we
// can get out without doing any work.

if (a.Length == 0 && b.Length > 0)
return -1;
else if (a.Length > 0 && b.Length == 0)
return 1;
else if (a.Length == 0 && b.Length == 0)
return 0;

//The order of chars - make this however you want.
string strNums = "0123456789";
string strSortOrder = "
.!#$%&'()*+,-/:;<=>?@[]^_{}~0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghi jklmnopqrstuvwxyz";

//Variables for comparing
bool aSmaller = true;
bool isFound = false;
int intIndex = 0;
// intLength determines the number of times to
loop.
We will loop
// until we hit the end of the shorter string -
a
or b.
int intLength = (a.Length < b.Length? a.Length:
b.Length);
string strNumA = "";
string strNumB = "";
int numA = 0;
int numB = 0;
int j = 0;
int k = 0;

//Do the compare while we are not at the end of
either string and haven't found
// the result.
while (!isFound && intIndex < intLength)
{
// if we are dealing with numbers, then sort
the numbers numerically
if (strNums.IndexOf(a[intIndex]) > -1 &&
strNums.IndexOf(b[intIndex]) > -1)
{
//Get all the numbers in string A until
we hit a non-number
j = intIndex;
while (j < a.Length &&
strNums.IndexOf(a[j]) > -1)
{
strNumA += a[j].ToString();
j++;
}
//Get all the numbers in string B until
we hit a non-number
k = intIndex;
while (k < b.Length &&
strNums.IndexOf(b[k]) > -1)
{
strNumB += b[k].ToString();
k++;
}

numA = Convert.ToInt32(strNumA);
numB = Convert.ToInt32(strNumB);

if (numA < numB) // a is before b in
sort order; a < b
return -1;
else if (numA > numB) // b is before a
in sort order; a > b
return 1;
else if (numA == numB)
{
//The numbers are the same.
Remove the number part from the strings
// and compare the remainder
of
the string.
return
CompareAlphaNum(a.Substring(strNumA.Length, a.Length-strNumA.Length),
b.Substring(strNumB.Length, b.Length-strNumB.Length));
}
}
else
{
if (strSortOrder.IndexOf(b[intIndex]) <
strSortOrder.IndexOf(a[intIndex]))
{
// If string a < b in a sort,
then
we're done
aSmaller = false;
isFound = true;
}
else if
(strSortOrder.IndexOf(b[intIndex]) > strSortOrder.IndexOf(a[intIndex]))
{
// If string a > b in a sort,
then
we're done
aSmaller = true;
isFound = true;
}
else if (( b.Length < a.Length) &&
(intIndex == intLength - 1))
{
// If the strings are equal up to
the length-th char but a is longer,
// then we're done.
aSmaller = false;
isFound = true;
}
else
{
// Otherwise, keep sorting
intIndex ++;
}
}
}

if ((a.Length == b.Length) && !isFound)
return 0; //strings are the same.
else if (aSmaller)
return -1; // a is before b in sort order; a
< b
else
return 1; // b is before a in sort order; ; a
b

}
}
}
2. Use the custom class using Array.Sort(myArray, new MyCompareClass()).

a. Add a new web page

b. Add:
using System.IO;
using System.Text;

c. Add a label to the form (lblDir) to display the sort

d. In the page load:

private void Page_Load(object sender, System.EventArgs e)
{
//Get files in dir
String strDir = MapPath("~/./");
DirectoryInfo curDir = new DirectoryInfo(strDir);
FileInfo [] fiArray = curDir.GetFiles();
string [] strFilenames = new string[fiArray.Length];
for (int j = 0; j < fiArray.Length; j++)
{
strFilenames[j] = fiArray[j].Name;
}

// Sort files
Array.Sort(strFilenames, new AlphaNumCompare());

//Display files
StringBuilder sbFiles = new StringBuilder();
for (int k = 0; k < strFilenames.Length; k++)
{
sbFiles.Append(strFilenames[k] + "<BR>");
}
lblDir.Text = sbFiles.ToString();
}

Lacey

"Federico G. Babelis" wrote:
Hi All:

I have this line of code, but the syntax check in VB.NET 2003 and also in
VB.NET 2005 Beta 2 shows as unknown:

Dim local4 As Byte

Fixed(local4 = AddressOf dest(offset))

CType(local4, Short) = CType(src, Short)

Return

End Fixed

What is the "FIXED and END FIXED" and how the syntax error can be "fixed"
???

Thx,

Federico

Jul 22 '05 #5

P: n/a
Hi Nick,

You and I are on two different topics. You are talking about lexographic
sorting (like a dictionary) and I am talking about alphanumeric sorting.
..NET Framework does not support alphanumeric sorting. (I'll prove it. Keep
breathing, Nick! Grab some coffee!)

Let's start with a definition for "alphanumeric sort": a re-ordering of data
so that numeric and alphabetic data sort as seperate groups. This is unlike
a "lexicographic sort" which re-orders data like a dictionary.

I looked through the articles you suggested. In all the examples, the
author either:
1. Compared strings that are completely numeric (for example: (int)"11"
compared to (int)"2")
2. Compared strings that are completely alphabetic (for example: "John"
compared to "Adam")
3. Or, displayed the same problem I solved:
http://aspnet.4guysfromrolla.com/dem...tArticles.aspx (See how
"dgExample2.aspx" is listed after "dgExample19.aspx"?)

None of these articles address the problem of alphanumeric sorting with
mixed strings like "22Beers" versus "3Beers".

For example, try this with the CompareTo method you suggested:
int intCompare = "22Beers".CompareTo("3Beers");
PROBLEM: The result is -1, meaning that "22Beers" < "3Beers". If we are
doing an alphabetic comparison, this is correct. But if we are doing an
alphanumeric comparison, this is incorrect because the number 22 is not less
than the number 3.

Let's look at a simple example with an array:
1. Create a web page with three labels (lblOriginal, lblLexo, lblAlphaNum)
2. In the Page_Load:
string[] arrOriginal = {"a3", "a111", "a2", "a1", "a11", "a22"};
for (int i = 0; i < arrOriginal.Length; i++ ) lblOriginal.Text +=
(arrOriginal[i].ToString() + "<BR>");

string[] arrLexo = {"a3", "a111", "a2", "a1", "a11", "a22"};
Array.Sort(arrLexo);
for (int j = 0; j < arrLexo.Length; j++ ) lblLexo.Text +=
(arrLexo[j].ToString() + "<BR>");

string[] arrAlphaNum = {"a3", "a111", "a2", "a1", "a11", "a22"};
Array.Sort(arrAlphaNum, new AlphaNumCompare());
for (int k = 0; k < arrAlphaNum.Length; k++ ) lblAlphaNum.Text +=
(arrAlphaNum[k].ToString() + "<BR>");

3. To the same project as the web page, add the class AlphaNumCompare()
which implements IComparer (provided in my previous posting).

Run the page, and you'll see the problem.
My original strings:
a3
a111
a2
a1
a11
a22

Microsoft .NET sort:
a1
a11
a111
a2
a22
a3

Custom alphanumeric sort:
a1
a2
a3
a11
a22
a111

See how a11 is before a2 in the Lexographic sort? This is a common problem
- getting string arrays to sort alphanumerically. I found a lot of postings
from programmers also looking for solutions. For example, if I have an array
of chapter titles for a book, my array needs to sort as:
1.1 Introduction
2.0 Procurement
....
2.9 Department-Specific Accounting
2.10 Delivery Addresses
3.0 Forms

You may want to check out this article from Microsoft which says "The .NET
Framework supports word [culture-sensitive comparison of strings], string
[similar to a word sort, except that there are no special cases], and ordinal
sort [compares the numeric value of each character; for example, a = 65]
rules." Note that it does not have any mention of comparing strings with
both alphabetic and numeric character and treating these character types as
seperate groups:
http://msdn.microsoft.com/library/de...classtopic.asp)

I hope Microsoft soon includes support for alphanumeric sorting of strings.

Lacey

"Nick Malik [Microsoft]" wrote:
Fascinating.

You make the following statement:
.NET does not support alphanumeric sort of arrays.


This is simply not true. For your example, you simply have to implement
IComparable for your complex type, you don't need to implement a string
comparison. That is built in.

In other words, you could replace the line:
return CompareAlphaNum(a, b);


with
return a.CompareTo(b);

and delete the entire "CompareAlphaNum" routine.
Note that the CompareAlphaNum routine below doesn't use the same collation
order that .Net uses. Perhaps you meant that .Net doesn't sort a capital
'Z' in front of a lowercase 'a'. If that is what you meant, you are right.
However, it is patently false to say that .Net doesn't support alphanumeric
sorting.

Some reference articles for you to read:
http://msdn.microsoft.com/library/en...sorttopic3.asp
http://odetocode.com/Articles/203.aspx
http://www.devx.com/dotnet/Article/21089
http://aspnet.4guysfromrolla.com/articles/060403-1.aspx

--
--- Nick Malik [Microsoft]
MCSD, CFPS, Certified Scrummaster
http://blogs.msdn.com/nickmalik

Disclaimer: Opinions expressed in this forum are my own, and not
representative of my employer.
I do not answer questions on behalf of my employer. I'm just a
programmer helping programmers.
--
"Lacey" <La***@discussions.microsoft.com> wrote in message
news:11**********************************@microsof t.com...
.NET does not support alphanumeric sort of arrays. (I hope that changes
soon!) Meanwhile, here is a solution.

You could use this in your listbox by sorting the items in an array and
then
adding the array items from 0 to length to your listbox.

1. Create a custom comparer class that implements IComparer:
using System;
using System.IO;

namespace Test1CSharp
{
/// <summary>
/// Lacey Orr
/// 29 June 2005
/// Alpha-numeric sorting solution.
/// </summary>

public class AlphaNumCompare : System.Collections.IComparer
{
public int Compare(Object a1, Object b1)
{
//In my case, I compared Directory objects. So I took
out
// the filenames / foldernames from the parameter
objects and
// passed those to the sort.

//The string variables to compare
string a = "";
string b = "";

//Is a1 a FileInfo?
if (a1.GetType() == System.Type.GetType("FileInfo"))
a = ((FileInfo)a1).Name;
else
a = a1.ToString();

//Is b1 a FileInfo?
if (b1.GetType() == System.Type.GetType("FileInfo"))
b = ((FileInfo)b1).Name;
else
b = b1.ToString();

return CompareAlphaNum(a, b);
}

// CompareAlphaNum: Does an alphabetic sort.
private static int CompareAlphaNum (string a, string b)
{
//Do a quick check for empty strings. If one
string
is empty, then we
// can get out without doing any work.

if (a.Length == 0 && b.Length > 0)
return -1;
else if (a.Length > 0 && b.Length == 0)
return 1;
else if (a.Length == 0 && b.Length == 0)
return 0;

//The order of chars - make this however you want.
string strNums = "0123456789";
string strSortOrder = "
.!#$%&'()*+,-/:;<=>?@[]^_{}~0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghi jklmnopqrstuvwxyz";

//Variables for comparing
bool aSmaller = true;
bool isFound = false;
int intIndex = 0;
// intLength determines the number of times to
loop.
We will loop
// until we hit the end of the shorter string -
a
or b.
int intLength = (a.Length < b.Length? a.Length:
b.Length);
string strNumA = "";
string strNumB = "";
int numA = 0;
int numB = 0;
int j = 0;
int k = 0;

//Do the compare while we are not at the end of
either string and haven't found
// the result.
while (!isFound && intIndex < intLength)
{
// if we are dealing with numbers, then sort
the numbers numerically
if (strNums.IndexOf(a[intIndex]) > -1 &&
strNums.IndexOf(b[intIndex]) > -1)
{
//Get all the numbers in string A until
we hit a non-number
j = intIndex;
while (j < a.Length &&
strNums.IndexOf(a[j]) > -1)
{
strNumA += a[j].ToString();
j++;
}
//Get all the numbers in string B until
we hit a non-number
k = intIndex;
while (k < b.Length &&
strNums.IndexOf(b[k]) > -1)
{
strNumB += b[k].ToString();
k++;
}

numA = Convert.ToInt32(strNumA);
numB = Convert.ToInt32(strNumB);

if (numA < numB) // a is before b in
sort order; a < b
return -1;
else if (numA > numB) // b is before a
in sort order; a > b
return 1;
else if (numA == numB)
{
//The numbers are the same.
Remove the number part from the strings
// and compare the remainder
of
the string.
return
CompareAlphaNum(a.Substring(strNumA.Length, a.Length-strNumA.Length),
b.Substring(strNumB.Length, b.Length-strNumB.Length));
}
}
else
{
if (strSortOrder.IndexOf(b[intIndex]) <
strSortOrder.IndexOf(a[intIndex]))
{
// If string a < b in a sort,
then
we're done
aSmaller = false;
isFound = true;
}
else if
(strSortOrder.IndexOf(b[intIndex]) > strSortOrder.IndexOf(a[intIndex]))
{
// If string a > b in a sort,
then
we're done
aSmaller = true;
isFound = true;
}
else if (( b.Length < a.Length) &&
(intIndex == intLength - 1))
{
// If the strings are equal up to
the length-th char but a is longer,
// then we're done.
aSmaller = false;
isFound = true;
}
else
{
// Otherwise, keep sorting
intIndex ++;
}
}
}

if ((a.Length == b.Length) && !isFound)
return 0; //strings are the same.
else if (aSmaller)
return -1; // a is before b in sort order; a
< b
else
return 1; // b is before a in sort order; ; a
b

}
}
}
2. Use the custom class using Array.Sort(myArray, new MyCompareClass()).

a. Add a new web page

b. Add:
using System.IO;
using System.Text;

c. Add a label to the form (lblDir) to display the sort

d. In the page load:

private void Page_Load(object sender, System.EventArgs e)
{
//Get files in dir
String strDir = MapPath("~/./");
DirectoryInfo curDir = new DirectoryInfo(strDir);
FileInfo [] fiArray = curDir.GetFiles();
string [] strFilenames = new string[fiArray.Length];
for (int j = 0; j < fiArray.Length; j++)
{
strFilenames[j] = fiArray[j].Name;
}

// Sort files
Array.Sort(strFilenames, new AlphaNumCompare());

//Display files
StringBuilder sbFiles = new StringBuilder();
for (int k = 0; k < strFilenames.Length; k++)
{
sbFiles.Append(strFilenames[k] + "<BR>");
}
lblDir.Text = sbFiles.ToString();
}

Lacey

"Federico G. Babelis" wrote:
Hi All:

I have this line of code, but the syntax check in VB.NET 2003 and also in
VB.NET 2005 Beta 2 shows as unknown:

Dim local4 As Byte

Fixed(local4 = AddressOf dest(offset))

CType(local4, Short) = CType(src, Short)

Return

End Fixed

What is the "FIXED and END FIXED" and how the syntax error can be "fixed"
???

Thx,

Federico


Jul 22 '05 #6

P: n/a
Thank you for the clarification, Lacey.

I admit that I had not seen the distinction that you are drawing, and I
appreciate the effort you put into describing it. I personally have not run
into this problem, but, by the effort you have gone to describe an answer,
it is clearly important for the applications that you create. I defer to
you on those requirements.

I suppose I would have solved the problems you describe by breaking the
strings up into groups and sorting the groups seperately, which is not
necessarily a better solution. For the kinds of data you are seeing, you
have a good answer.

I do not know if this kind of sorting is specifically "on the plate" for
anyone. If you'd like to see Microsoft implement any feature, I suggest
that you send that description to the MS****@microsoft.com e-mail address.
(perhaps package up your code and the solution below and send it in). You
could also submit an article to a developer magazine to describe your
problem and solution, or create a small project in GotDotNet.com to share
the code. These techniques make it easier for folks to find and reuse your
code than posting on a newsgroup.

Thanks again,
--
--- Nick Malik [Microsoft]
MCSD, CFPS, Certified Scrummaster
http://blogs.msdn.com/nickmalik

Disclaimer: Opinions expressed in this forum are my own, and not
representative of my employer.
I do not answer questions on behalf of my employer. I'm just a
programmer helping programmers.
--
"Lacey" <La***@discussions.microsoft.com> wrote in message
news:CE**********************************@microsof t.com...
Hi Nick,

You and I are on two different topics. You are talking about lexographic
sorting (like a dictionary) and I am talking about alphanumeric sorting.
.NET Framework does not support alphanumeric sorting. (I'll prove it.
Keep
breathing, Nick! Grab some coffee!)

Let's start with a definition for "alphanumeric sort": a re-ordering of
data
so that numeric and alphabetic data sort as seperate groups. This is
unlike
a "lexicographic sort" which re-orders data like a dictionary.

I looked through the articles you suggested. In all the examples, the
author either:
1. Compared strings that are completely numeric (for example: (int)"11"
compared to (int)"2")
2. Compared strings that are completely alphabetic (for example: "John"
compared to "Adam")
3. Or, displayed the same problem I solved:
http://aspnet.4guysfromrolla.com/dem...tArticles.aspx (See how
"dgExample2.aspx" is listed after "dgExample19.aspx"?)

None of these articles address the problem of alphanumeric sorting with
mixed strings like "22Beers" versus "3Beers".

For example, try this with the CompareTo method you suggested:
int intCompare = "22Beers".CompareTo("3Beers");
PROBLEM: The result is -1, meaning that "22Beers" < "3Beers". If we are
doing an alphabetic comparison, this is correct. But if we are doing an
alphanumeric comparison, this is incorrect because the number 22 is not
less
than the number 3.

Let's look at a simple example with an array:
1. Create a web page with three labels (lblOriginal, lblLexo, lblAlphaNum)
2. In the Page_Load:
string[] arrOriginal = {"a3", "a111", "a2", "a1", "a11", "a22"};
for (int i = 0; i < arrOriginal.Length; i++ ) lblOriginal.Text +=
(arrOriginal[i].ToString() + "<BR>");

string[] arrLexo = {"a3", "a111", "a2", "a1", "a11", "a22"};
Array.Sort(arrLexo);
for (int j = 0; j < arrLexo.Length; j++ ) lblLexo.Text +=
(arrLexo[j].ToString() + "<BR>");

string[] arrAlphaNum = {"a3", "a111", "a2", "a1", "a11", "a22"};
Array.Sort(arrAlphaNum, new AlphaNumCompare());
for (int k = 0; k < arrAlphaNum.Length; k++ ) lblAlphaNum.Text +=
(arrAlphaNum[k].ToString() + "<BR>");

3. To the same project as the web page, add the class AlphaNumCompare()
which implements IComparer (provided in my previous posting).

Run the page, and you'll see the problem.
My original strings:
a3
a111
a2
a1
a11
a22

Microsoft .NET sort:
a1
a11
a111
a2
a22
a3

Custom alphanumeric sort:
a1
a2
a3
a11
a22
a111

See how a11 is before a2 in the Lexographic sort? This is a common
problem
- getting string arrays to sort alphanumerically. I found a lot of
postings
from programmers also looking for solutions. For example, if I have an
array
of chapter titles for a book, my array needs to sort as:
1.1 Introduction
2.0 Procurement
...
2.9 Department-Specific Accounting
2.10 Delivery Addresses
3.0 Forms

You may want to check out this article from Microsoft which says "The .NET
Framework supports word [culture-sensitive comparison of strings], string
[similar to a word sort, except that there are no special cases], and
ordinal
sort [compares the numeric value of each character; for example, a = 65]
rules." Note that it does not have any mention of comparing strings with
both alphabetic and numeric character and treating these character types
as
seperate groups:
http://msdn.microsoft.com/library/de...classtopic.asp)

I hope Microsoft soon includes support for alphanumeric sorting of
strings.

Lacey

"Nick Malik [Microsoft]" wrote:
Fascinating.

You make the following statement:
> .NET does not support alphanumeric sort of arrays.


This is simply not true. For your example, you simply have to implement
IComparable for your complex type, you don't need to implement a string
comparison. That is built in.

In other words, you could replace the line:
> return CompareAlphaNum(a, b);


with
return a.CompareTo(b);

and delete the entire "CompareAlphaNum" routine.
Note that the CompareAlphaNum routine below doesn't use the same
collation
order that .Net uses. Perhaps you meant that .Net doesn't sort a capital
'Z' in front of a lowercase 'a'. If that is what you meant, you are
right.
However, it is patently false to say that .Net doesn't support
alphanumeric
sorting.

Some reference articles for you to read:
http://msdn.microsoft.com/library/en...sorttopic3.asp
http://odetocode.com/Articles/203.aspx
http://www.devx.com/dotnet/Article/21089
http://aspnet.4guysfromrolla.com/articles/060403-1.aspx

--
--- Nick Malik [Microsoft]
MCSD, CFPS, Certified Scrummaster
http://blogs.msdn.com/nickmalik

Disclaimer: Opinions expressed in this forum are my own, and not
representative of my employer.
I do not answer questions on behalf of my employer. I'm just a
programmer helping programmers.
--
"Lacey" <La***@discussions.microsoft.com> wrote in message
news:11**********************************@microsof t.com...
> .NET does not support alphanumeric sort of arrays. (I hope that
> changes
> soon!) Meanwhile, here is a solution.
>
> You could use this in your listbox by sorting the items in an array and
> then
> adding the array items from 0 to length to your listbox.
>
> 1. Create a custom comparer class that implements IComparer:
> using System;
> using System.IO;
>
> namespace Test1CSharp
> {
> /// <summary>
> /// Lacey Orr
> /// 29 June 2005
> /// Alpha-numeric sorting solution.
> /// </summary>
>
> public class AlphaNumCompare : System.Collections.IComparer
> {
> public int Compare(Object a1, Object b1)
> {
> //In my case, I compared Directory objects. So I took
> out
> // the filenames / foldernames from the parameter
> objects and
> // passed those to the sort.
>
> //The string variables to compare
> string a = "";
> string b = "";
>
> //Is a1 a FileInfo?
> if (a1.GetType() == System.Type.GetType("FileInfo"))
> a = ((FileInfo)a1).Name;
> else
> a = a1.ToString();
>
> //Is b1 a FileInfo?
> if (b1.GetType() == System.Type.GetType("FileInfo"))
> b = ((FileInfo)b1).Name;
> else
> b = b1.ToString();
>
> return CompareAlphaNum(a, b);
> }
>
> // CompareAlphaNum: Does an alphabetic sort.
> private static int CompareAlphaNum (string a, string
> b)
> {
> //Do a quick check for empty strings. If one
> string
> is empty, then we
> // can get out without doing any work.
>
> if (a.Length == 0 && b.Length > 0)
> return -1;
> else if (a.Length > 0 && b.Length == 0)
> return 1;
> else if (a.Length == 0 && b.Length == 0)
> return 0;
>
> //The order of chars - make this however you
> want.
> string strNums = "0123456789";
> string strSortOrder = "
> .!#$%&'()*+,-/:;<=>?@[]^_{}~0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghi jklmnopqrstuvwxyz";
>
> //Variables for comparing
> bool aSmaller = true;
> bool isFound = false;
> int intIndex = 0;
> // intLength determines the number of times to
> loop.
> We will loop
> // until we hit the end of the shorter
> string -
> a
> or b.
> int intLength = (a.Length < b.Length? a.Length:
> b.Length);
> string strNumA = "";
> string strNumB = "";
> int numA = 0;
> int numB = 0;
> int j = 0;
> int k = 0;
>
> //Do the compare while we are not at the end of
> either string and haven't found
> // the result.
> while (!isFound && intIndex < intLength)
> {
> // if we are dealing with numbers, then
> sort
> the numbers numerically
> if (strNums.IndexOf(a[intIndex]) > -1 &&
> strNums.IndexOf(b[intIndex]) > -1)
> {
> //Get all the numbers in string A
> until
> we hit a non-number
> j = intIndex;
> while (j < a.Length &&
> strNums.IndexOf(a[j]) > -1)
> {
> strNumA += a[j].ToString();
> j++;
> }
> //Get all the numbers in string B
> until
> we hit a non-number
> k = intIndex;
> while (k < b.Length &&
> strNums.IndexOf(b[k]) > -1)
> {
> strNumB += b[k].ToString();
> k++;
> }
>
> numA = Convert.ToInt32(strNumA);
> numB = Convert.ToInt32(strNumB);
>
> if (numA < numB) // a is before b in
> sort order; a < b
> return -1;
> else if (numA > numB) // b is before
> a
> in sort order; a > b
> return 1;
> else if (numA == numB)
> {
> //The numbers are the same.
> Remove the number part from the strings
> // and compare the
> remainder
> of
> the string.
> return
> CompareAlphaNum(a.Substring(strNumA.Length, a.Length-strNumA.Length),
> b.Substring(strNumB.Length, b.Length-strNumB.Length));
> }
> }
> else
> {
> if
> (strSortOrder.IndexOf(b[intIndex]) <
> strSortOrder.IndexOf(a[intIndex]))
> {
> // If string a < b in a sort,
> then
> we're done
> aSmaller = false;
> isFound = true;
> }
> else if
> (strSortOrder.IndexOf(b[intIndex]) > strSortOrder.IndexOf(a[intIndex]))
> {
> // If string a > b in a sort,
> then
> we're done
> aSmaller = true;
> isFound = true;
> }
> else if (( b.Length < a.Length) &&
> (intIndex == intLength - 1))
> {
> // If the strings are equal up
> to
> the length-th char but a is longer,
> // then we're done.
> aSmaller = false;
> isFound = true;
> }
> else
> {
> // Otherwise, keep sorting
> intIndex ++;
> }
> }
> }
>
> if ((a.Length == b.Length) && !isFound)
> return 0; //strings are the same.
> else if (aSmaller)
> return -1; // a is before b in sort order;
> a
> < b
> else
> return 1; // b is before a in sort order;
> ; a
>> b
> }
> }
> }
>
>
> 2. Use the custom class using Array.Sort(myArray, new
> MyCompareClass()).
>
> a. Add a new web page
>
> b. Add:
> using System.IO;
> using System.Text;
>
> c. Add a label to the form (lblDir) to display the sort
>
> d. In the page load:
>
> private void Page_Load(object sender, System.EventArgs e)
> {
> //Get files in dir
> String strDir = MapPath("~/./");
> DirectoryInfo curDir = new DirectoryInfo(strDir);
> FileInfo [] fiArray = curDir.GetFiles();
> string [] strFilenames = new string[fiArray.Length];
> for (int j = 0; j < fiArray.Length; j++)
> {
> strFilenames[j] = fiArray[j].Name;
> }
>
> // Sort files
> Array.Sort(strFilenames, new AlphaNumCompare());
>
> //Display files
> StringBuilder sbFiles = new StringBuilder();
> for (int k = 0; k < strFilenames.Length; k++)
> {
> sbFiles.Append(strFilenames[k] + "<BR>");
> }
> lblDir.Text = sbFiles.ToString();
> }
>
> Lacey
>
> "Federico G. Babelis" wrote:
>
>> Hi All:
>>
>> I have this line of code, but the syntax check in VB.NET 2003 and also
>> in
>> VB.NET 2005 Beta 2 shows as unknown:
>>
>> Dim local4 As Byte
>>
>> Fixed(local4 = AddressOf dest(offset))
>>
>> CType(local4, Short) = CType(src, Short)
>>
>> Return
>>
>> End Fixed
>>
>> What is the "FIXED and END FIXED" and how the syntax error can be
>> "fixed"
>> ???
>>
>> Thx,
>>
>> Federico
>>
>>
>>


Jul 22 '05 #7

P: n/a
On Wed, 13 Jul 2005 12:51:01 -0700, Lacey wrote:
You and I are on two different topics. You are talking about lexographic
sorting (like a dictionary) and I am talking about alphanumeric sorting.
.NET Framework does not support alphanumeric sorting. (I'll prove it. Keep
breathing, Nick! Grab some coffee!)


[snip]

You've demonstrated what you mean admirably. The problem is that the exact
phrase "alphanumeric sorting" is not frequently used to represent the type
of problem you have solved.
Jul 22 '05 #8

This discussion thread is closed

Replies have been disabled for this discussion.