Sorting DataGrid bound to collection

[Pete Davis]

A different question this time. I have a DataGrid bound to a collection. Is
there any way for me to allow sorting? The DataGrid.AllowSorting=true
doesn't work, but that's probably because it can't assume the data types and
thus can't sort them.

I thought about implementing IComparable, but I don't see how that would
work since it doesn't apply generically to all the fields/properties of the
class.

Thanks.

Pete

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

Simply, sort the collection :)

Use the class below to sort a collection , it use reflection.

I have a better documented version but it's at home, if you have any doubt
of how/why it please post back with your comments.
It's very simple you create a new ClassComparer and say what property of the
class you want to use for it, you can even use compound expressions like
"BirthDate.Year" it goes down recursively.

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
You may use it like this ( this method belong to a strong typed collection
of a type named LocationPoint )

public LocationPointCollection Sort( string sortParam, SortDirection
direction)
{
ArrayList newlist = (ArrayList)InnerList.Clone();
ClassSorter sorter = new ClassSorter( sortParam, SortByType.Property,
direction);
newlist.Sort( sorter);
return new LocationPointCollection( newlist);
}

This is the class

public class ClassSorter: IComparer
{
protected string sortBy;
protected SortByType sortByType;
protected SortDirection sortDirection;
#region Constructors
public ClassSorter(string sortBy, SortByType sortByType, SortDirection
sortDirection)
{
this.sortBy = sortBy;
this.sortByType = sortByType;
this.sortDirection = sortDirection;
}
#endregion

int Compare( object x, object y, string comparer)
{
if ( (x== null ) && (y==null) )
return 0;
if ( x == null )
return -1;
if ( y == null )
return 1;
if ( comparer.IndexOf( ".") != -1 )
{
//split the string
string[] parts = comparer.Split( new char[]{ '.'} );
return Compare( x.GetType().GetProperty( parts[0]).GetValue(x, null) ,
y.GetType().GetProperty( parts[0]).GetValue(y, null) , parts[1]
);
}
else
{
IComparable icx, icy;
icx =
(IComparable)x.GetType().GetProperty( comparer).GetValue(x, null);
icy =
(IComparable)y.GetType().GetProperty( comparer).GetValue(y, null);

if ( x.GetType().GetProperty(comparer).PropertyType ==
typeof(System.String) )
{
icx = (IComparable) icx.ToString().ToUpper();
icy = (IComparable) icy.ToString().ToUpper();
}

if(this.sortDirection == SortDirection.Descending)
return icy.CompareTo(icx);
else
return icx.CompareTo(icy);
}

}

public int Compare(object x, object y)
{
return Compare( x, y, sortBy);
}

}

public enum SortByType
{
Method = 0,
Property = 1
}

public enum SortDirection
{
Ascending = 0,
Descending = 1
}

"Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
news:eP********************@giganews.com...

A different question this time. I have a DataGrid bound to a collection. Is
there any way for me to allow sorting? The DataGrid.AllowSorting=true
doesn't work, but that's probably because it can't assume the data types
and
thus can't sort them.

I thought about implementing IComparable, but I don't see how that would
work since it doesn't apply generically to all the fields/properties of
the
class.

Thanks.

Pete

[Pete Davis]

Very nice class. Thanks.

So, what you're saying is that I need to handle the click on the column
headers and handle the sorting myself, though, right?

Thanks.

Pete

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us> wrote
in message news:uo****************@TK2MSFTNGP14.phx.gbl...

Hi,

Simply, sort the collection :)

Use the class below to sort a collection , it use reflection.

I have a better documented version but it's at home, if you have any doubt
of how/why it please post back with your comments.
It's very simple you create a new ClassComparer and say what property of the class you want to use for it, you can even use compound expressions like
"BirthDate.Year" it goes down recursively.

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
You may use it like this ( this method belong to a strong typed collection
of a type named LocationPoint )

public LocationPointCollection Sort( string sortParam, SortDirection
direction)
{
ArrayList newlist = (ArrayList)InnerList.Clone();
ClassSorter sorter = new ClassSorter( sortParam, SortByType.Property,
direction);
newlist.Sort( sorter);
return new LocationPointCollection( newlist);
}

This is the class

public class ClassSorter: IComparer
{
protected string sortBy;
protected SortByType sortByType;
protected SortDirection sortDirection;
#region Constructors
public ClassSorter(string sortBy, SortByType sortByType, SortDirection
sortDirection)
{
this.sortBy = sortBy;
this.sortByType = sortByType;
this.sortDirection = sortDirection;
}
#endregion

int Compare( object x, object y, string comparer)
{
if ( (x== null ) && (y==null) )
return 0;
if ( x == null )
return -1;
if ( y == null )
return 1;
if ( comparer.IndexOf( ".") != -1 )
{
//split the string
string[] parts = comparer.Split( new char[]{ '.'} );
return Compare( x.GetType().GetProperty( parts[0]).GetValue(x, null) ,
y.GetType().GetProperty( parts[0]).GetValue(y, null) , parts[1]
);
}
else
{
IComparable icx, icy;
icx =
(IComparable)x.GetType().GetProperty( comparer).GetValue(x, null);
icy =
(IComparable)y.GetType().GetProperty( comparer).GetValue(y, null);

if ( x.GetType().GetProperty(comparer).PropertyType ==
typeof(System.String) )
{
icx = (IComparable) icx.ToString().ToUpper();
icy = (IComparable) icy.ToString().ToUpper();
}

if(this.sortDirection == SortDirection.Descending)
return icy.CompareTo(icx);
else
return icx.CompareTo(icy);
}

}

public int Compare(object x, object y)
{
return Compare( x, y, sortBy);
}

}

public enum SortByType
{
Method = 0,
Property = 1
}

public enum SortDirection
{
Ascending = 0,
Descending = 1
}

"Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
news:eP********************@giganews.com...

A different question this time. I have a DataGrid bound to a collection. Is there any way for me to allow sorting? The DataGrid.AllowSorting=true
doesn't work, but that's probably because it can't assume the data types
and
thus can't sort them.

I thought about implementing IComparable, but I don't see how that would
work since it doesn't apply generically to all the fields/properties of
the
class.

Thanks.

Pete

[Pete Davis]

Ignacio,

That worked beautifully. Handled the click, created the ClassComparer
based on the column header that was clicked, sorted, and re-bound the grid.

One question (and I posted this same thing in regards to a listbox
earlier). Is there any way to get the grid to update when there are changes
made to the collection? The only method I've found is to set the DataSource
to null and then set it back to the collection.

Thanks.

Pete

"Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
news:md********************@giganews.com...

Very nice class. Thanks.

So, what you're saying is that I need to handle the click on the column
headers and handle the sorting myself, though, right?

Thanks.

Pete

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us> wrote in message news:uo****************@TK2MSFTNGP14.phx.gbl...

Hi,

Simply, sort the collection :)

Use the class below to sort a collection , it use reflection.

I have a better documented version but it's at home, if you have any doubt

of how/why it please post back with your comments.
It's very simple you create a new ClassComparer and say what property of the

class you want to use for it, you can even use compound expressions like
"BirthDate.Year" it goes down recursively.

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
You may use it like this ( this method belong to a strong typed collection of a type named LocationPoint )

public LocationPointCollection Sort( string sortParam, SortDirection
direction)
{
ArrayList newlist = (ArrayList)InnerList.Clone();
ClassSorter sorter = new ClassSorter( sortParam, SortByType.Property,
direction);
newlist.Sort( sorter);
return new LocationPointCollection( newlist);
}

This is the class

public class ClassSorter: IComparer
{
protected string sortBy;
protected SortByType sortByType;
protected SortDirection sortDirection;
#region Constructors
public ClassSorter(string sortBy, SortByType sortByType, SortDirection
sortDirection)
{
this.sortBy = sortBy;
this.sortByType = sortByType;
this.sortDirection = sortDirection;
}
#endregion

int Compare( object x, object y, string comparer)
{
if ( (x== null ) && (y==null) )
return 0;
if ( x == null )
return -1;
if ( y == null )
return 1;
if ( comparer.IndexOf( ".") != -1 )
{
//split the string
string[] parts = comparer.Split( new char[]{ '.'} );
return Compare( x.GetType().GetProperty( parts[0]).GetValue(x, null) , y.GetType().GetProperty( parts[0]).GetValue(y, null) , parts[1]
);
}
else
{
IComparable icx, icy;
icx =
(IComparable)x.GetType().GetProperty( comparer).GetValue(x, null);
icy =
(IComparable)y.GetType().GetProperty( comparer).GetValue(y, null);

if ( x.GetType().GetProperty(comparer).PropertyType ==
typeof(System.String) )
{
icx = (IComparable) icx.ToString().ToUpper();
icy = (IComparable) icy.ToString().ToUpper();
}

if(this.sortDirection == SortDirection.Descending)
return icy.CompareTo(icx);
else
return icx.CompareTo(icy);
}

}

public int Compare(object x, object y)
{
return Compare( x, y, sortBy);
}

}

public enum SortByType
{
Method = 0,
Property = 1
}

public enum SortDirection
{
Ascending = 0,
Descending = 1
}

"Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
news:eP********************@giganews.com...

A different question this time. I have a DataGrid bound to a collection. Is there any way for me to allow sorting? The DataGrid.AllowSorting=true
doesn't work, but that's probably because it can't assume the data

types and
thus can't sort them.

I thought about implementing IComparable, but I don't see how that would work since it doesn't apply generically to all the fields/properties of the
class.

Thanks.

Pete

[Ignacio Machin \( .NET/ C# MVP \)]

hi

you do not need to set it to null, just set the datasource to the collection
and call bind

yes, that is the only method

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
news:bb********************@giganews.com...

Ignacio,

That worked beautifully. Handled the click, created the ClassComparer
based on the column header that was clicked, sorted, and re-bound the
grid.

One question (and I posted this same thing in regards to a listbox
earlier). Is there any way to get the grid to update when there are
changes
made to the collection? The only method I've found is to set the
DataSource
to null and then set it back to the collection.

Thanks.

Pete

"Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
news:md********************@giganews.com...

Very nice class. Thanks.

So, what you're saying is that I need to handle the click on the column
headers and handle the sorting myself, though, right?

Thanks.

Pete

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us>

wrote

in message news:uo****************@TK2MSFTNGP14.phx.gbl...

> Hi,
>
> Simply, sort the collection :)
>
> Use the class below to sort a collection , it use reflection.
>
> I have a better documented version but it's at home, if you have any doubt > of how/why it please post back with your comments.
> It's very simple you create a new ClassComparer and say what property
> of

the

> class you want to use for it, you can even use compound expressions
> like
> "BirthDate.Year" it goes down recursively.
>
> cheers,
>
>
>
> --
> Ignacio Machin,
> ignacio.machin AT dot.state.fl.us
> Florida Department Of Transportation
>
>
> You may use it like this ( this method belong to a strong typed collection > of a type named LocationPoint )
>
> public LocationPointCollection Sort( string sortParam, SortDirection
> direction)
> {
> ArrayList newlist = (ArrayList)InnerList.Clone();
> ClassSorter sorter = new ClassSorter( sortParam,
> SortByType.Property,
> direction);
> newlist.Sort( sorter);
> return new LocationPointCollection( newlist);
> }
>
> This is the class
>
> public class ClassSorter: IComparer
> {
> protected string sortBy;
> protected SortByType sortByType;
> protected SortDirection sortDirection;
>
>
> #region Constructors
> public ClassSorter(string sortBy, SortByType sortByType,
> SortDirection
> sortDirection)
> {
> this.sortBy = sortBy;
> this.sortByType = sortByType;
> this.sortDirection = sortDirection;
> }
> #endregion
>
> int Compare( object x, object y, string comparer)
> {
> if ( (x== null ) && (y==null) )
> return 0;
> if ( x == null )
> return -1;
> if ( y == null )
> return 1;
> if ( comparer.IndexOf( ".") != -1 )
> {
> //split the string
> string[] parts = comparer.Split( new char[]{ '.'} );
> return Compare( x.GetType().GetProperty( parts[0]).GetValue(x,
> null) , > y.GetType().GetProperty( parts[0]).GetValue(y, null) ,
> parts[1]
> );
> }
> else
> {
> IComparable icx, icy;
> icx =
> (IComparable)x.GetType().GetProperty( comparer).GetValue(x, null);
> icy =
> (IComparable)y.GetType().GetProperty( comparer).GetValue(y, null);
>
> if ( x.GetType().GetProperty(comparer).PropertyType ==
> typeof(System.String) )
> {
> icx = (IComparable) icx.ToString().ToUpper();
> icy = (IComparable) icy.ToString().ToUpper();
> }
>
> if(this.sortDirection == SortDirection.Descending)
> return icy.CompareTo(icx);
> else
> return icx.CompareTo(icy);
> }
>
> }
>
> public int Compare(object x, object y)
> {
> return Compare( x, y, sortBy);
> }
>
> }
>
> public enum SortByType
> {
> Method = 0,
> Property = 1
> }
>
> public enum SortDirection
> {
> Ascending = 0,
> Descending = 1
> }
>
>
>
>
>
> "Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
> news:eP********************@giganews.com...
> >A different question this time. I have a DataGrid bound to a collection.

Is

> > there any way for me to allow sorting? The DataGrid.AllowSorting=true
> > doesn't work, but that's probably because it can't assume the data

types > > and
> > thus can't sort them.
> >
> > I thought about implementing IComparable, but I don't see how that would > > work since it doesn't apply generically to all the fields/properties of > > the
> > class.
> >
> > Thanks.
> >
> > Pete
> >
> >
>
>

[Pete Davis]

There is no Bind() method in DataGrid, at least not that I'm seeing.

Setting the DataSource binds the collection to the grid, but updates aren't
automatically detected by the grid because the CollectionBase (and my
collection for that matter) doesn't implement IBindingList.

Pete

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us> wrote
in message news:en****************@TK2MSFTNGP09.phx.gbl...

hi

you do not need to set it to null, just set the datasource to the collection and call bind

yes, that is the only method

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
news:bb********************@giganews.com...

Ignacio,

That worked beautifully. Handled the click, created the ClassComparer
based on the column header that was clicked, sorted, and re-bound the
grid.

One question (and I posted this same thing in regards to a listbox
earlier). Is there any way to get the grid to update when there are
changes
made to the collection? The only method I've found is to set the
DataSource
to null and then set it back to the collection.

Thanks.

Pete

"Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
news:md********************@giganews.com...

Very nice class. Thanks.

So, what you're saying is that I need to handle the click on the column
headers and handle the sorting myself, though, right?

Thanks.

Pete

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us>

wrote

in message news:uo****************@TK2MSFTNGP14.phx.gbl...
> Hi,
>
> Simply, sort the collection :)
>
> Use the class below to sort a collection , it use reflection.
>
> I have a better documented version but it's at home, if you have any

doubt

> of how/why it please post back with your comments.
> It's very simple you create a new ClassComparer and say what property
> of
the
> class you want to use for it, you can even use compound expressions
> like
> "BirthDate.Year" it goes down recursively.
>
> cheers,
>
>
>
> --
> Ignacio Machin,
> ignacio.machin AT dot.state.fl.us
> Florida Department Of Transportation
>
>
> You may use it like this ( this method belong to a strong typed

collection

> of a type named LocationPoint )
>
> public LocationPointCollection Sort( string sortParam, SortDirection > direction)
> {
> ArrayList newlist = (ArrayList)InnerList.Clone();
> ClassSorter sorter = new ClassSorter( sortParam,
> SortByType.Property,
> direction);
> newlist.Sort( sorter);
> return new LocationPointCollection( newlist);
> }
>
> This is the class
>
> public class ClassSorter: IComparer
> {
> protected string sortBy;
> protected SortByType sortByType;
> protected SortDirection sortDirection;
>
>
> #region Constructors
> public ClassSorter(string sortBy, SortByType sortByType,
> SortDirection
> sortDirection)
> {
> this.sortBy = sortBy;
> this.sortByType = sortByType;
> this.sortDirection = sortDirection;
> }
> #endregion
>
> int Compare( object x, object y, string comparer)
> {
> if ( (x== null ) && (y==null) )
> return 0;
> if ( x == null )
> return -1;
> if ( y == null )
> return 1;
> if ( comparer.IndexOf( ".") != -1 )
> {
> //split the string
> string[] parts = comparer.Split( new char[]{ '.'} );
> return Compare( x.GetType().GetProperty( parts[0]).GetValue(x,
> null)

,

> y.GetType().GetProperty( parts[0]).GetValue(y, null) ,
> parts[1]
> );
> }
> else
> {
> IComparable icx, icy;
> icx =
> (IComparable)x.GetType().GetProperty( comparer).GetValue(x, null); > icy =
> (IComparable)y.GetType().GetProperty( comparer).GetValue(y, null); >
> if ( x.GetType().GetProperty(comparer).PropertyType ==
> typeof(System.String) )
> {
> icx = (IComparable) icx.ToString().ToUpper();
> icy = (IComparable) icy.ToString().ToUpper();
> }
>
> if(this.sortDirection == SortDirection.Descending)
> return icy.CompareTo(icx);
> else
> return icx.CompareTo(icy);
> }
>
> }
>
> public int Compare(object x, object y)
> {
> return Compare( x, y, sortBy);
> }
>
> }
>
> public enum SortByType
> {
> Method = 0,
> Property = 1
> }
>
> public enum SortDirection
> {
> Ascending = 0,
> Descending = 1
> }
>
>
>
>
>
> "Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
> news:eP********************@giganews.com...
> >A different question this time. I have a DataGrid bound to a

collection.

Is
> > there any way for me to allow sorting? The DataGrid.AllowSorting=true > > doesn't work, but that's probably because it can't assume the data

types

> > and
> > thus can't sort them.
> >
> > I thought about implementing IComparable, but I don't see how that

would

> > work since it doesn't apply generically to all the

fields/properties of

> > the
> > class.
> >
> > Thanks.
> >
> > Pete
> >
> >
>
>

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

Sorry pete, it;s DataBind()

Detecting updates could be done doing something like this:
1- Declare a public event in the collection , when a new elem is added you
can fire this event, the client( the form where the grid is hosted )
subscribe to it and react accordingly.

Detecting a modification is more difficult if not impossible to do though.

Cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
"Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
news:A9********************@giganews.com...

There is no Bind() method in DataGrid, at least not that I'm seeing.

Setting the DataSource binds the collection to the grid, but updates
aren't
automatically detected by the grid because the CollectionBase (and my
collection for that matter) doesn't implement IBindingList.

Pete

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us>
wrote
in message news:en****************@TK2MSFTNGP09.phx.gbl...

hi

you do not need to set it to null, just set the datasource to the

collection

and call bind

yes, that is the only method

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
news:bb********************@giganews.com...

> Ignacio,
>
> That worked beautifully. Handled the click, created the ClassComparer
> based on the column header that was clicked, sorted, and re-bound the
> grid.
>
> One question (and I posted this same thing in regards to a listbox
> earlier). Is there any way to get the grid to update when there are
> changes
> made to the collection? The only method I've found is to set the
> DataSource
> to null and then set it back to the collection.
>
> Thanks.
>
> Pete
>
> "Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
> news:md********************@giganews.com...
>> Very nice class. Thanks.
>>
>> So, what you're saying is that I need to handle the click on the
>> column
>> headers and handle the sorting myself, though, right?
>>
>> Thanks.
>>
>> Pete
>>
>> "Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us>
> wrote
>> in message news:uo****************@TK2MSFTNGP14.phx.gbl...
>> > Hi,
>> >
>> > Simply, sort the collection :)
>> >
>> > Use the class below to sort a collection , it use reflection.
>> >
>> > I have a better documented version but it's at home, if you have any
> doubt
>> > of how/why it please post back with your comments.
>> > It's very simple you create a new ClassComparer and say what
>> > property
>> > of
>> the
>> > class you want to use for it, you can even use compound expressions
>> > like
>> > "BirthDate.Year" it goes down recursively.
>> >
>> > cheers,
>> >
>> >
>> >
>> > --
>> > Ignacio Machin,
>> > ignacio.machin AT dot.state.fl.us
>> > Florida Department Of Transportation
>> >
>> >
>> > You may use it like this ( this method belong to a strong typed
> collection
>> > of a type named LocationPoint )
>> >
>> > public LocationPointCollection Sort( string sortParam, SortDirection >> > direction)
>> > {
>> > ArrayList newlist = (ArrayList)InnerList.Clone();
>> > ClassSorter sorter = new ClassSorter( sortParam,
>> > SortByType.Property,
>> > direction);
>> > newlist.Sort( sorter);
>> > return new LocationPointCollection( newlist);
>> > }
>> >
>> > This is the class
>> >
>> > public class ClassSorter: IComparer
>> > {
>> > protected string sortBy;
>> > protected SortByType sortByType;
>> > protected SortDirection sortDirection;
>> >
>> >
>> > #region Constructors
>> > public ClassSorter(string sortBy, SortByType sortByType,
>> > SortDirection
>> > sortDirection)
>> > {
>> > this.sortBy = sortBy;
>> > this.sortByType = sortByType;
>> > this.sortDirection = sortDirection;
>> > }
>> > #endregion
>> >
>> > int Compare( object x, object y, string comparer)
>> > {
>> > if ( (x== null ) && (y==null) )
>> > return 0;
>> > if ( x == null )
>> > return -1;
>> > if ( y == null )
>> > return 1;
>> > if ( comparer.IndexOf( ".") != -1 )
>> > {
>> > //split the string
>> > string[] parts = comparer.Split( new char[]{ '.'} );
>> > return Compare( x.GetType().GetProperty( parts[0]).GetValue(x,
>> > null)
> ,
>> > y.GetType().GetProperty( parts[0]).GetValue(y, null) ,
>> > parts[1]
>> > );
>> > }
>> > else
>> > {
>> > IComparable icx, icy;
>> > icx =
>> > (IComparable)x.GetType().GetProperty( comparer).GetValue(x, null); >> > icy =
>> > (IComparable)y.GetType().GetProperty( comparer).GetValue(y, null); >> >
>> > if ( x.GetType().GetProperty(comparer).PropertyType ==
>> > typeof(System.String) )
>> > {
>> > icx = (IComparable) icx.ToString().ToUpper();
>> > icy = (IComparable) icy.ToString().ToUpper();
>> > }
>> >
>> > if(this.sortDirection == SortDirection.Descending)
>> > return icy.CompareTo(icx);
>> > else
>> > return icx.CompareTo(icy);
>> > }
>> >
>> > }
>> >
>> > public int Compare(object x, object y)
>> > {
>> > return Compare( x, y, sortBy);
>> > }
>> >
>> > }
>> >
>> > public enum SortByType
>> > {
>> > Method = 0,
>> > Property = 1
>> > }
>> >
>> > public enum SortDirection
>> > {
>> > Ascending = 0,
>> > Descending = 1
>> > }
>> >
>> >
>> >
>> >
>> >
>> > "Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
>> > news:eP********************@giganews.com...
>> > >A different question this time. I have a DataGrid bound to a
> collection.
>> Is
>> > > there any way for me to allow sorting? The DataGrid.AllowSorting=true >> > > doesn't work, but that's probably because it can't assume the data
> types
>> > > and
>> > > thus can't sort them.
>> > >
>> > > I thought about implementing IComparable, but I don't see how that
> would
>> > > work since it doesn't apply generically to all the fields/properties > of
>> > > the
>> > > class.
>> > >
>> > > Thanks.
>> > >
>> > > Pete
>> > >
>> > >
>> >
>> >
>>
>>
>
>

[Pete Davis]

Sorry, I guess there was some confusion. I'm using Windows forms, not Web
forms. WinForms controls don't have DataBind().

Thanks anyway. I ended up just implementing IBindingList in the collection
and that took care of handling both the sorting and the updating issues.

Pete

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us> wrote
in message news:%2******************@tk2msftngp13.phx.gbl...

Hi,

Sorry pete, it;s DataBind()

Detecting updates could be done doing something like this:
1- Declare a public event in the collection , when a new elem is added you
can fire this event, the client( the form where the grid is hosted )
subscribe to it and react accordingly.

Detecting a modification is more difficult if not impossible to do though.

Cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
"Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
news:A9********************@giganews.com...

There is no Bind() method in DataGrid, at least not that I'm seeing.

Setting the DataSource binds the collection to the grid, but updates
aren't
automatically detected by the grid because the CollectionBase (and my
collection for that matter) doesn't implement IBindingList.

Pete

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us>
wrote
in message news:en****************@TK2MSFTNGP09.phx.gbl...

hi

you do not need to set it to null, just set the datasource to the

collection

and call bind

yes, that is the only method

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
news:bb********************@giganews.com...
> Ignacio,
>
> That worked beautifully. Handled the click, created the ClassComparer > based on the column header that was clicked, sorted, and re-bound the
> grid.
>
> One question (and I posted this same thing in regards to a listbox
> earlier). Is there any way to get the grid to update when there are
> changes
> made to the collection? The only method I've found is to set the
> DataSource
> to null and then set it back to the collection.
>
> Thanks.
>
> Pete
>
> "Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
> news:md********************@giganews.com...
>> Very nice class. Thanks.
>>
>> So, what you're saying is that I need to handle the click on the
>> column
>> headers and handle the sorting myself, though, right?
>>
>> Thanks.
>>
>> Pete
>>
>> "Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us> > wrote
>> in message news:uo****************@TK2MSFTNGP14.phx.gbl...
>> > Hi,
>> >
>> > Simply, sort the collection :)
>> >
>> > Use the class below to sort a collection , it use reflection.
>> >
>> > I have a better documented version but it's at home, if you have any > doubt
>> > of how/why it please post back with your comments.
>> > It's very simple you create a new ClassComparer and say what
>> > property
>> > of
>> the
>> > class you want to use for it, you can even use compound expressions >> > like
>> > "BirthDate.Year" it goes down recursively.
>> >
>> > cheers,
>> >
>> >
>> >
>> > --
>> > Ignacio Machin,
>> > ignacio.machin AT dot.state.fl.us
>> > Florida Department Of Transportation
>> >
>> >
>> > You may use it like this ( this method belong to a strong typed
> collection
>> > of a type named LocationPoint )
>> >
>> > public LocationPointCollection Sort( string sortParam,

SortDirection

>> > direction)
>> > {
>> > ArrayList newlist = (ArrayList)InnerList.Clone();
>> > ClassSorter sorter = new ClassSorter( sortParam,
>> > SortByType.Property,
>> > direction);
>> > newlist.Sort( sorter);
>> > return new LocationPointCollection( newlist);
>> > }
>> >
>> > This is the class
>> >
>> > public class ClassSorter: IComparer
>> > {
>> > protected string sortBy;
>> > protected SortByType sortByType;
>> > protected SortDirection sortDirection;
>> >
>> >
>> > #region Constructors
>> > public ClassSorter(string sortBy, SortByType sortByType,
>> > SortDirection
>> > sortDirection)
>> > {
>> > this.sortBy = sortBy;
>> > this.sortByType = sortByType;
>> > this.sortDirection = sortDirection;
>> > }
>> > #endregion
>> >
>> > int Compare( object x, object y, string comparer)
>> > {
>> > if ( (x== null ) && (y==null) )
>> > return 0;
>> > if ( x == null )
>> > return -1;
>> > if ( y == null )
>> > return 1;
>> > if ( comparer.IndexOf( ".") != -1 )
>> > {
>> > //split the string
>> > string[] parts = comparer.Split( new char[]{ '.'} );
>> > return Compare( x.GetType().GetProperty( parts[0]).GetValue(x,
>> > null)
> ,
>> > y.GetType().GetProperty( parts[0]).GetValue(y, null) ,
>> > parts[1]
>> > );
>> > }
>> > else
>> > {
>> > IComparable icx, icy;
>> > icx =
>> > (IComparable)x.GetType().GetProperty( comparer).GetValue(x,

null);

>> > icy =
>> > (IComparable)y.GetType().GetProperty( comparer).GetValue(y,

null);

>> >
>> > if ( x.GetType().GetProperty(comparer).PropertyType ==
>> > typeof(System.String) )
>> > {
>> > icx = (IComparable) icx.ToString().ToUpper();
>> > icy = (IComparable) icy.ToString().ToUpper();
>> > }
>> >
>> > if(this.sortDirection == SortDirection.Descending)
>> > return icy.CompareTo(icx);
>> > else
>> > return icx.CompareTo(icy);
>> > }
>> >
>> > }
>> >
>> > public int Compare(object x, object y)
>> > {
>> > return Compare( x, y, sortBy);
>> > }
>> >
>> > }
>> >
>> > public enum SortByType
>> > {
>> > Method = 0,
>> > Property = 1
>> > }
>> >
>> > public enum SortDirection
>> > {
>> > Ascending = 0,
>> > Descending = 1
>> > }
>> >
>> >
>> >
>> >
>> >
>> > "Pete Davis" <pd******@NOSPAM.hotmail.com> wrote in message
>> > news:eP********************@giganews.com...
>> > >A different question this time. I have a DataGrid bound to a
> collection.
>> Is
>> > > there any way for me to allow sorting? The

DataGrid.AllowSorting=true

>> > > doesn't work, but that's probably because it can't assume the data > types
>> > > and
>> > > thus can't sort them.
>> > >
>> > > I thought about implementing IComparable, but I don't see how that > would
>> > > work since it doesn't apply generically to all the

fields/properties

> of
>> > > the
>> > > class.
>> > >
>> > > Thanks.
>> > >
>> > > Pete
>> > >
>> > >
>> >
>> >
>>
>>
>
>