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listView question


With this program I can do one selection,
but upon the second I get an error where
///////////////// is indicated. Please help.

using System;
using System.Drawing;
using System.Collecti ons;
using System.Componen tModel;
using System.Windows. Forms;
using System.Data;
namespace WindowsApplicat ion1
{
public class Form1 : System.Windows. Forms.Form
{
private System.Windows. Forms.TextBox textBox1;
private System.Windows. Forms.ColumnHea der columnHeader1;
private System.Windows. Forms.ColumnHea der columnHeader2;
private System.Windows. Forms.ListView listView1;
private System.Componen tModel.Containe r components = null;
public Form1()
{
InitializeCompo nent();
}
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Disp ose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
private void InitializeCompo nent()
{
this.textBox1 = new System.Windows. Forms.TextBox() ;
this.columnHead er1 = new System.Windows. Forms.ColumnHea der();
this.columnHead er2 = new System.Windows. Forms.ColumnHea der();
this.listView1 = new System.Windows. Forms.ListView( );
this.SuspendLay out();
//
// textBox1
//
this.textBox1.L ocation = new System.Drawing. Point(16, 192);
this.textBox1.N ame = "textBox1";
this.textBox1.S ize = new System.Drawing. Size(256, 20);
this.textBox1.T abIndex = 1;
this.textBox1.T ext = "";
//
// columnHeader1
//
this.columnHead er1.Text = "number";
this.columnHead er1.Width = 49;
//
// columnHeader2
//
this.columnHead er2.Text = "name";
this.columnHead er2.Width = 186;
//
// listView1
//
this.listView1. Columns.AddRang e(new System.Windows. Forms.ColumnHea der[] {
this.columnHead er1,
this.columnHead er2});
this.listView1. GridLines = true;
this.listView1. LabelEdit = true;
this.listView1. Location = new System.Drawing. Point(24, 16);
this.listView1. Name = "listView1" ;
this.listView1. Size = new System.Drawing. Size(256, 160);
this.listView1. TabIndex = 0;
this.listView1. View = System.Windows. Forms.View.Deta ils;
this.listView1. SelectedIndexCh anged += new
System.EventHan dler(this.listV iew1_SelectedIn dexChanged);
//
// Form1
//
this.AutoScaleB aseSize = new System.Drawing. Size(5, 13);
this.ClientSize = new System.Drawing. Size(292, 266);
this.Controls.A dd(this.textBox 1);
this.Controls.A dd(this.listVie w1);
this.FormBorder Style = System.Windows. Forms.FormBorde rStyle.FixedToo lWindow;
this.Name = "Form1";
this.ShowInTask bar = false;
this.Text = "Form1";
this.Load += new System.EventHan dler(this.Form1 _Load);
this.ResumeLayo ut(false);
}
#endregion
[STAThread]
static void Main()
{
Application.Run (new Form1());
}
private void listView1_Selec tedIndexChanged (object sender, EventArgs e)
{
ListView.Select edListViewItemC ollection contents =
this.listView1. SelectedItems;
textBox1.Text = contents[0].SubItems[1].Text;/////////////////////error
}
private void Form1_Load(obje ct sender, System.EventArg s e)
{
string [ ] show0 = new string [] {"one","two","t hree","four"};
string [ ] show1 = new string [] {"ene","mene"," mane","moo"};
for (int i = 0; i<show0.Length; i++)
{
ListViewItem listItem = new ListViewItem(sh ow0[i]);
using System;
using System.Drawing;
using System.Collecti ons;
using System.Componen tModel;
using System.Windows. Forms;
using System.Data;
namespace WindowsApplicat ion1
{
public class Form1 : System.Windows. Forms.Form
{
private System.Windows. Forms.TextBox textBox1;
private System.Windows. Forms.ColumnHea der columnHeader1;
private System.Windows. Forms.ColumnHea der columnHeader2;
private System.Windows. Forms.ListView listView1;
private System.Componen tModel.Containe r components = null;
public Form1()
{
InitializeCompo nent();
}
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Disp ose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
private void InitializeCompo nent()
{
this.textBox1 = new System.Windows. Forms.TextBox() ;
this.columnHead er1 = new System.Windows. Forms.ColumnHea der();
this.columnHead er2 = new System.Windows. Forms.ColumnHea der();
this.listView1 = new System.Windows. Forms.ListView( );
this.SuspendLay out();
//
// textBox1
//
this.textBox1.L ocation = new System.Drawing. Point(16, 192);
this.textBox1.N ame = "textBox1";
this.textBox1.S ize = new System.Drawing. Size(256, 20);
this.textBox1.T abIndex = 1;
this.textBox1.T ext = "";
//
// columnHeader1
//
this.columnHead er1.Text = "number";
this.columnHead er1.Width = 49;
//
// columnHeader2
//
this.columnHead er2.Text = "name";
this.columnHead er2.Width = 186;
//
// listView1
//
this.listView1. Columns.AddRang e(new System.Windows. Forms.ColumnHea der[] {
this.columnHead er1,
this.columnHead er2});
this.listView1. GridLines = true;
this.listView1. LabelEdit = true;
this.listView1. Location = new System.Drawing. Point(24, 16);
this.listView1. Name = "listView1" ;
this.listView1. Size = new System.Drawing. Size(256, 160);
this.listView1. TabIndex = 0;
this.listView1. View = System.Windows. Forms.View.Deta ils;
this.listView1. SelectedIndexCh anged += new
System.EventHan dler(this.listV iew1_SelectedIn dexChanged);
//
// Form1
//
this.AutoScaleB aseSize = new System.Drawing. Size(5, 13);
this.ClientSize = new System.Drawing. Size(292, 266);
this.Controls.A dd(this.textBox 1);
this.Controls.A dd(this.listVie w1);
this.FormBorder Style = System.Windows. Forms.FormBorde rStyle.FixedToo lWindow;
this.Name = "Form1";
this.ShowInTask bar = false;
this.Text = "Form1";
this.Load += new System.EventHan dler(this.Form1 _Load);
this.ResumeLayo ut(false);
}
#endregion
[STAThread]
static void Main()
{
Application.Run (new Form1());
}
private void listView1_Selec tedIndexChanged (object sender, EventArgs e)
{
ListView.Select edListViewItemC ollection contents =
this.listView1. SelectedItems;
textBox1.Text = contents[0].SubItems[1].Text;/////////////////////error
}
private void Form1_Load(obje ct sender, System.EventArg s e)
{
string [ ] show0 = new string [] {"one","two","t hree","four"};
string [ ] show1 = new string [] {"ene","mene"," mane","moo"};
for (int i = 0; i<show0.Length; i++)
{
ListViewItem listItem = new ListViewItem(sh ow0[i]);
listItem.SubIte ms.Add(show1[i]);
listView1.Items .Add(listItem);
}
}
}
}
listItem.SubIte ms.Add(show1[i]);
listView1.Items .Add(listItem);
}
}
}
}


Nov 16 '05 #1
6 2543
The error is because an event is firing with nothing in the SelectedItems.. .
so trying to access contents[0] fails because there is nothing in contents.

Its a bit strange that there is an event fired with no selected items - it
seems that, when you click on a 2nd different item (without the shift key -
i.e. not making a multi selection), internally the listbox selection is
cleared, causing the event to fire with SelectedItems containing nothing,
before the 2nd item is added to the SelectedItems and the event is fired
again.

You should always protect against there being no selection anyway,
especially in a multiselect listbox - i.e. something like this:

if (contents.Count > 0)
textBox1.Text = contents[0].SubItems[1].Text;
else
textBox1.Text = "(Nothing)" ;
Cheers,
Pete Beech
"Vanessa" <va*****@hipper dy.hop> wrote in message
news:10******** *******@news-01.evisp.enerte l.nl...

With this program I can do one selection,
but upon the second I get an error where
///////////////// is indicated. Please help.

using System;
using System.Drawing;
using System.Collecti ons;
using System.Componen tModel;
using System.Windows. Forms;
using System.Data;
namespace WindowsApplicat ion1
{
public class Form1 : System.Windows. Forms.Form
{
private System.Windows. Forms.TextBox textBox1;
private System.Windows. Forms.ColumnHea der columnHeader1;
private System.Windows. Forms.ColumnHea der columnHeader2;
private System.Windows. Forms.ListView listView1;
private System.Componen tModel.Containe r components = null;
public Form1()
{
InitializeCompo nent();
}
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Disp ose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
private void InitializeCompo nent()
{
this.textBox1 = new System.Windows. Forms.TextBox() ;
this.columnHead er1 = new System.Windows. Forms.ColumnHea der();
this.columnHead er2 = new System.Windows. Forms.ColumnHea der();
this.listView1 = new System.Windows. Forms.ListView( );
this.SuspendLay out();
//
// textBox1
//
this.textBox1.L ocation = new System.Drawing. Point(16, 192);
this.textBox1.N ame = "textBox1";
this.textBox1.S ize = new System.Drawing. Size(256, 20);
this.textBox1.T abIndex = 1;
this.textBox1.T ext = "";
//
// columnHeader1
//
this.columnHead er1.Text = "number";
this.columnHead er1.Width = 49;
//
// columnHeader2
//
this.columnHead er2.Text = "name";
this.columnHead er2.Width = 186;
//
// listView1
//
this.listView1. Columns.AddRang e(new System.Windows. Forms.ColumnHea der[] {
this.columnHead er1,
this.columnHead er2});
this.listView1. GridLines = true;
this.listView1. LabelEdit = true;
this.listView1. Location = new System.Drawing. Point(24, 16);
this.listView1. Name = "listView1" ;
this.listView1. Size = new System.Drawing. Size(256, 160);
this.listView1. TabIndex = 0;
this.listView1. View = System.Windows. Forms.View.Deta ils;
this.listView1. SelectedIndexCh anged += new
System.EventHan dler(this.listV iew1_SelectedIn dexChanged);
//
// Form1
//
this.AutoScaleB aseSize = new System.Drawing. Size(5, 13);
this.ClientSize = new System.Drawing. Size(292, 266);
this.Controls.A dd(this.textBox 1);
this.Controls.A dd(this.listVie w1);
this.FormBorder Style = System.Windows. Forms.FormBorde rStyle.FixedToo lWindow; this.Name = "Form1";
this.ShowInTask bar = false;
this.Text = "Form1";
this.Load += new System.EventHan dler(this.Form1 _Load);
this.ResumeLayo ut(false);
}
#endregion
[STAThread]
static void Main()
{
Application.Run (new Form1());
}
private void listView1_Selec tedIndexChanged (object sender, EventArgs e)
{
ListView.Select edListViewItemC ollection contents =
this.listView1. SelectedItems;
textBox1.Text = contents[0].SubItems[1].Text;/////////////////////error
}
private void Form1_Load(obje ct sender, System.EventArg s e)
{
string [ ] show0 = new string [] {"one","two","t hree","four"};
string [ ] show1 = new string [] {"ene","mene"," mane","moo"};
for (int i = 0; i<show0.Length; i++)
{
ListViewItem listItem = new ListViewItem(sh ow0[i]);
listItem.SubIte ms.Add(show1[i]);
listView1.Items .Add(listItem);
}
}
}
}

Nov 16 '05 #2
Thank you Pete,

Your suggestion solved that one.

Can you also input into a listView? I do not see a "Read Only = true/false"
in with the Properties.
"Pete Beech" <pe*********@ho tmail.nojunk.co m> wrote in message
news:un******** *****@TK2MSFTNG P12.phx.gbl...
You should always protect against there being no selection anyway,
especially in a multiselect listbox - i.e. something like this:

if (contents.Count > 0)
textBox1.Text = contents[0].SubItems[1].Text;
else
textBox1.Text = "(Nothing)" ;

Nov 16 '05 #3
Setting LabelEdit to true allows the first column (the 'label') to be
edited. (In the example, LabelEdit is set to true.) To edit, you can single
click an item that is already selected.

"Patrick de Ridder" <se***@freeler. nl> wrote in message
news:10******** *******@news-01.evisp.enerte l.nl...
Thank you Pete,

Your suggestion solved that one.

Can you also input into a listView? I do not see a "Read Only = true/false" in with the Properties.
"Pete Beech" <pe*********@ho tmail.nojunk.co m> wrote in message
news:un******** *****@TK2MSFTNG P12.phx.gbl...
You should always protect against there being no selection anyway,
especially in a multiselect listbox - i.e. something like this:

if (contents.Count > 0)
textBox1.Text = contents[0].SubItems[1].Text;
else
textBox1.Text = "(Nothing)" ;


Nov 16 '05 #4
What about the second column? Can't be done?

"Pete Beech" <pe*********@ho tmail.nojunk.co m> wrote in message
news:eG******** ******@tk2msftn gp13.phx.gbl...
Setting LabelEdit to true allows the first column (the 'label') to be
edited. (In the example, LabelEdit is set to true.) To edit, you can single click an item that is already selected.


Nov 16 '05 #5
Not as far as I can see, but I have never looked into it before.

Pete

"Vanessa" <no*******@all. here> wrote in message
news:10******** *******@news-01.evisp.enerte l.nl...
What about the second column? Can't be done?

"Pete Beech" <pe*********@ho tmail.nojunk.co m> wrote in message
news:eG******** ******@tk2msftn gp13.phx.gbl...
Setting LabelEdit to true allows the first column (the 'label') to be
edited. (In the example, LabelEdit is set to true.) To edit, you can

single
click an item that is already selected.


Nov 16 '05 #6
Pete,
Thanks for responding. Guess it cannot be done.
Don't see much use for just being able to edit
the first column and not the orthers.

"Pete Beech" <pe*********@ho tmail.nojunk.co m> wrote in message
news:%2******** ********@TK2MSF TNGP12.phx.gbl. ..
Not as far as I can see, but I have never looked into it before.

Pete

"Vanessa" <no*******@all. here> wrote in message
news:10******** *******@news-01.evisp.enerte l.nl...
What about the second column? Can't be done?

"Pete Beech" <pe*********@ho tmail.nojunk.co m> wrote in message
news:eG******** ******@tk2msftn gp13.phx.gbl...
Setting LabelEdit to true allows the first column (the 'label') to be
edited. (In the example, LabelEdit is set to true.) To edit, you can

single
click an item that is already selected.



Nov 16 '05 #7

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