Custom control problem.
I'm modding a textbox so that it will always have a "%"
sign at the end of it.
I have overrided the Text property to account for the "%"
value within the textbox and have add BaseText to give
access to the baseText method too.
I have the text_changed event handler wired up to this
method, problem is that it works ONLY every other time.
The statement that works every other time is this:
string s = ResultOfOtherTh ings();
this.BaseText = s + "%";
In debugger I can see it doesn't add the "%";
I've tried:
s = s+"%";
But in the debugger s appears without the "%".
So therefore I ask is there anything "special" about '%'
or "%" because it's making little sense at best.
Full code follows:
public class PercentBox : System.Windows. Forms.TextBox
{
//Characters that are allowed to be typed into the box
private ArrayList allowedChars;
public ArrayList AllowedChars
{
get{return allowedChars;}
set{allowedChar s = value;}
}
// my override of text
public override string Text
{
get
{
if(base.Text.Le ngth>1)
{
return base.Text.Subst ring(0, base.Text.Lengt h-1);
}
else
{
return "";
}
}
set{base.Text = value + "%";}
}
// to give access to the base still
public string BaseText
{
get{return base.Text;}
set{base.Text = value;}
}
public PercentBox()
{
base.Text = "%";
this.TextChange d += new EventHandler
(PercentBox_Tex tChanged);
this.KeyPress += new
System.Windows. Forms.KeyPressE ventHandler
(PercentBox_Key Press);
allowedChars = new ArrayList(10);
allowedChars.Ad d('0');
allowedChars.Ad d('1');
allowedChars.Ad d('2');
allowedChars.Ad d('3');
allowedChars.Ad d('4');
allowedChars.Ad d('5');
allowedChars.Ad d('6');
allowedChars.Ad d('7');
allowedChars.Ad d('8');
allowedChars.Ad d('9');
allowedChars.Ad d((char)8);
allowedChars.Ad d('.');
allowedChars.Ad d('%');
}
protected override void OnPaint(PaintEv entArgs pe)
{
// TODO: Add custom paint code here
// Calling the base class OnPaint
base.OnPaint(pe );
}
private void PercentBox_Text Changed(object sender,
System.EventArg s e)
{
PercentBox pBox = (PercentBox) sender;
if(pBox.BaseTex t.Length>0)
{
// to make sure there only 1 % mark so the next if
//statement will work
string s = OnlyOneCharOfTy pe(pBox.BaseTex t, '%');
if(s[s.Length-1] != '%')
{
// remove the eventhandler during the operation
this.TextChange d -= new EventHandler
(PercentBox_Tex tChanged);
string victim = pBox.BaseText;
// removes all '%' from victim
s = RemoveCharFromS tring(victim, '%');
// make sure there is only one decimal place
s = OnlyOneCharOfTy pe(s, '.');
pBox.BaseText = s+"%";
this.TextChange d += new EventHandler
(PercentBox_Tex tChanged);
}
}
else
{
pBox.BaseText = "%";
}
}
private string OnlyOneCharOfTy pe(string victim, char type)
{
bool found = false;
char[] result = new char[victim.Length];
int charCtr = 0;
foreach(char c in victim)
{
if(c == type)
{
if(found != true)
{
found = true;
result[charCtr] = c;
charCtr++;
}
else
{
continue;
}
}
else
{
result[charCtr] = c;
charCtr++;
}
}
StringBuilder sb = new StringBuilder() ;
foreach(char ch in result)
{
try
{
sb.Append(ch);
}
catch(Exception )
{
break;
}
}
string theResult = sb.ToString();
theResult = theResult.Trim( );
return theResult;
}
private string RemoveCharFromS tring(string victim, char c)
{
char[] result = new char[victim.Length];
int charCtr = 0;
foreach(char ch in victim)
{
if(ch != c)
{
result[charCtr] = ch;
charCtr++;
}
}
StringBuilder sb = new StringBuilder() ;
foreach(char ch in result)
{
try
{
sb.Append(ch);
}
catch(Exception )
{
break;
}
}
string theResult = sb.ToString();
theResult = theResult.Trim( );
return theResult;
}
/// <summary>
/// // Ensures that no letters can be added to a control
that has the key press event linked to this
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void PercentBox_KeyP ress(object sender,
System.Windows. Forms.KeyPressE ventArgs e)
{
char c = e.KeyChar;
if(!ValidatePre ssEntry(c))
{
e.Handled = true;
}
}
/// <summary>
/// // Ensures that no letters can be
added to a control that has the key press event linked to
this save the '.' character for decimal places
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private bool ValidatePressEn try(char c)
{
bool bob = false;
foreach(char okChar in allowedChars)
{
if(okChar == c)
{
bob = true;
}
}
return bob;
}
}
