I have a ComboBox with items in it. I also have a SelectedIndexChange event.
When I open the ComboBox and hover over an item, the SelectedIndex property seems to change to that item. I'd only like it to change when I click on the item. Is it possible to disable that behavior?
I have a timer that refreshes an Image based on SelectedIndex of ComboBox, but still, even if I highlight an item but don't select, why does the Image changes while it should not change and it only should change when I select an item.
The Problem
When the the mouse moves on items of ComboBox, the SelectedIndex changes but SelectedIndexChanged event doesn't fire, so in your timer Tick event, you will see the change while SelectedIndexChanged doesn't fire.
Scenario of reproducing the problem
To simply reproduce the problem, put a Timer on a form and enable it, then handle its Tick event. Also add a ComboBox and add some items to it and handle its SelectedIndexChanged event. When you open the dropdown and move mouse over items, you will see the Text of form changes to the index of item that is under the cursor, while SelectedIndexChanged doesn't fire and no MessageBox will show.
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
MessageBox.Show(this.comboBox1.SelectedIndex.ToString());
}
private void timer1_Tick(object sender, EventArgs e)
{
this.Text = this.comboBox1.SelectedIndex.ToString();
}
The Solution for your case
You can simply check if the dropdown is not open using DroppedDown property of ComboBox, then do the job:
private void timer1_Tick(object sender, EventArgs e)
{
if(!this.comboBox1.DroppedDown)
this.Text = this.comboBox1.SelectedIndex.ToString();
}
Related
I read many answers, but in my case, I don't know why I can't capture the mouse click on the list items, it works only when I click on the object (ComboBox).
internal System.Windows.Forms.ComboBox MyComboBox;
this.MyComboBox.MouseDown += new System.Windows.Forms.MouseEventHandler(this.MyComboBox_MouseDown);
...
private void MyComboBox_MouseDown(object sender, MouseEventArgs e)
{
Console.WriteLine("MouseDown...");
}
When I click on the ComboBox itself or in the arrow I get the click event, but when I click on any items in the list of this ComboBox the click event never fires.
From other answers, they seem to use SelectedIndexChanged() event for Mouse Clicks... but this event also fires when it changes programmatically.
How I can detect a MouseDown on a ComboBox item?
For example, I add a DropDown Control and its ButtonClick event handler method:
private void dropDown1_ButtonClick(object sender, RibbonControlEventArgs e)
{
MessageBox.Show("I am clicked.");
}
but, when I click DropDown control, it doesn.t show the message, which mean the event not fired. How to explain this?
The event is fired when a button is clicked on the list. So, you need to fill the list of Buttons like shown on the screenshot:
I'm programming in WinForms.
I have a ComboBox set with an initial gray ForeColor. My goal is to change the text color of this ComboBox when the user start to type something.
I tried to use _TextChanged and TextUpdate Events but don't work.
private void ComboBox1_TextChanged(Object sender, EventArgs e)
{
ComboBox1.ForeColor = SystemColors.ControlText;
}
I already used the Event _SelectedIndexChanged to change the text color when the user select an item from the drop-down list, and it works well, but the text remains gray if the user types something (there is an AutoCompleteCustomSource collection associated to the ComboBox so the user can write instead to use the drop-down list).
Any suggestion?
EDIT
I have solved this way:
Registering in Form1.Designer.cs:
this.ComboBox1.KeyUp += new System.Windows.Forms.KeyEventHandler(this.ComboBox1_KeyUp);`
Using this code:
private void ComboBox1_KeyUp(Object sender, KeyEventArgs e)
{
ComboBox1.ForeColor = SystemColors.ControlText;
}
Use KeyUp, KeyDown, or KeyPress events fired by the textbox. You probably don't want KeyPress for this purpose. TextChanged fires when the text has already been changed, which is why the new character being typed doesn't have a different color when you subscribe to it.
Have you looked at KeyUp event? MSDN Keyup
You should be able to subscribe to this event and do whatever you want inside it.
I want to perform some action when some text is selected from a RichTextBox. So in what event of the RichTextBox should I write my logic?
I'm designing a notepad. I have one Menustrip and in the Menustrip I have Copy, Paste, Undo and Redo option. I want these options to be visible to the users only when a user selects any text in the RichTextBox.
I've tried it in many events but haven't succeeded so far.
I've tried in RichTextBox the Mousecapturechanged event and Toolstripmenu menu active event.
I am using C#.
Kindly help.
The best solution would be to subscribe to the MouseUp event of the RichTextBox and within the event handler, check if the length of the selected text is greater than 0 like this:
private void richTextBox1_MouseUp(object sender, MouseEventArgs e)
{
if (richTextBox1.SelectedText.Length > 0)
{
// Show the Copy, Paste, Cut Buttons...
}
}
This is because the SelectionChanged event fires whenever the selection is changed and so will not even let you select text properly.
You can use SelectionChanged event and check if the cursor has changed or a part of text has been selected.
private void richTextBox1_SelectionChanged(object sender, EventArgs e)
{
if (richTextBox1.SelectionLength < 2) return;
//Show the menu
}
You can use the SelectionChanged event which:
Occurs when the selection of text within the control has changed.
MSDN Link - RichTextBox.
This event would be ideal for what you aim to achieve.
Now you also need to use this properly. This event will fire even if you type something. So you have to verify that something is selected like this:
private void richTextBox1_SelectionChanged(object sender, EventArgs e)
{
if (richTextBox1.SelectedText.Length > 1)
{
// Show the Copy, Paste, Cut Buttons...
}
}
I am working on windows form application. I have a combo box.
I given combobox
DropDownStyle property to DropDownList. A clear button I given code like this:
cmbvisitpurpose.Text = ""
If the combobox property drop down list then it wont clear selected text in the combobox.
So in clear button code I have to give
cmbvisitpurpose.SelectedIndex = -1
But, in cmbvisitpurpose.SelectedIndex event I have written lot of code some another purpose. While clearing every time that affecting that code also, so is there any other method to clear combobox selected text?
so..
I dont want to use SelectedIndex . Is there any other method I can use instead of SelectedIndex
You can try to use RemoveAt after you select your element to be removed just like that:
private void button1_Click(object sender, EventArgs e)
{
//Remove item at Index 1
comboBox1.Items.RemoveAt(comboBox1.SelectedIndex = 1) ;
}
You can even clear all you element in this way:
private void button1_Click(object sender, EventArgs e)
{
//Remove all the item
comboBox1.Items.Clear();
}
Hope this helps.
If you have DropDownStyle set to DropDownList then I am afraid you do not have any other way to clear the selected text. I can not think of any "some another method" as mentioned by you in the comment. If you try and clear the selection SelectionIndexChanged will fire.
A simple solution according to me would have been an if clause in your event handler to just bypass the case when SelectedIndex is -1
If you do not want your event to fire at all one way could be to Remove the event handler every time you clear the selection. Say on a button click you could do:
cmbvisitpurpose.SelectedIndexChanged -= cmbvisitpurpose_SelectedIndexChanged;
cmbvisitpurpose.SelectedIndex = -1;
cmbvisitpurpose.SelectedIndexChanged += cmbvisitpurpose_SelectedIndexChanged;