I have a listbox in one of my user controls, and if certain keys are pressed it acts accordingly. My problem is that there are already some keys that do specific functions for the listbox (eg. arrows move up and down, dynamic search etc.). What I need is to disable all of these and handle the listbox on my own. Any way I could achieve this?
Inside the Form or UserControl where you have the listbox specified add this code:
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (msg.HWnd == yourListBox.Handle)
{
//Check the keyData and do your custom processing
return true;//Say that you processed the key.
}
return base.ProcessCmdKey(ref msg, keyData);
}
If you want to disable all keys on your ListBox, you can use the following code
private void Listbox_KeyDown(object sender, System.Windows.Input.KeyEventArgs e)
{
e.Handled = true;
}
You can accept some especial keys if you want as well. For example if you want to accept just the Enter key
private void ListBox_KeyDown(object sender, System.Windows.Input.KeyEventArgs e)
{
If e.Keycode==keys.Enter
{
//do what you want
}
Else
{
e.Handled = true;
}
}
Related
I have a MaskedTextBox that formats text to look like (###) ###-####
After entering the first 3 digits, they like to press "TAB" to the next set. Unfortunately by pressing TAB, they are in the next field.
So my boss asked me to modify the application so that the users remain in the same field but the cursor is in the next group.
private void maskedTextBoxHomePhone_KeyPress(object sender, KeyPressEventArgs e)
{
MaskedTextBox mtb = (MaskedTextBox)sender;
if (e.KeyChar == (char)Keys.Tab)
{
if (mtb.TextLength == 3)
{
mtb.SelectionStart = 4;
}
}
}
I've also tried
private void maskedTextBoxHomePhone_KeyDown(object sender, KeyEventArgs e)
{
MaskedTextBox mtb = (MaskedTextBox)sender;
if (e.KeyCode == Keys.Tab)
{
if (mtb.TextLength == 3)
{
mtb.SelectionStart = 4;
}
}
}
Tabs have a special meaning, that will cause the focus to change, so the event handler won't get called.
You could work around this by using the Leave event of a text box and counting the textlength that you have stored in some local variable:
private void maskedTextBoxHomePhone_Leave(object sender, EventArgs e)
{
if (_mtbTextLength == 3) { //change selection start and goes back to masked text box }
}
Anyway, actually I would try to convince my boss otherwise. Do you
really need this? Tabs are always used to change fields, you can get
your users confused.
Another option would be to change the Tab behaviour by overriding the ProcessCmdKey:
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (keyData == Keys.Tab)
{
//Do something
}
}
I am trying to bind a keyboard button (preferably "ESC") to stop the code that is running inside the method. But the thing is, it only works with actual buttons, is there anyway to bypass this so it works when pressing labels aswell?
private void label1_Click(object sender, EventArgs e)
{
if (e.Control && e.KeyCode.ToString() == "ESC")
{
MessageBox.Show("This does now work");
}
}
I've read somewhere that it is possible its just that the Visual Studio GUi doesnt provide it, but you can do it with code somehow, is this true?
I am not sure what you are trying to do. The following will get the Escape key when it is pressed when the focus is in the form regardless of what control has the focus. Just add this to the form (the code of course).
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (keyData == (Keys.Escape))
{
MessageBox.Show("This works");
return true;
}
return base.ProcessCmdKey(ref msg, keyData);
}
I am working in a webform and have a form with a tab bar on it. Each tab has multiple text boxes in it. I have the tab indexes incremented, starting with 1 for each tab. I want to tab from tab to tab if the user hits the end of the form and hits tab.
I used the leave method and changed the tabs for my tab control the only problem is if I didn't hit tab and say I click to another control on that tab it will still shoot over to the new tab.
I figure a way to solve this would be to listen for the tab key press and if the key press is tab on leave then change the form to the other tab, I just can't seem to get it to work though. I have tried with keypress and keydown but neither will pick up that tab as a key. If I was to say click or hit start typing it will trigger the events but tab will not.
Any suggestions?
I have tried these and none of these event would even trigger.
private void afsiTxtDaysForTempOEpriceOverrides_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == 11)
{
afsiTxtDaysForTempOEpriceOverrides_Leave(sender, e);
}
}
private void afsiTxtDaysForTempOEpriceOverrides_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == "11")
{
afsiTxtDaysForTempOEpriceOverrides_Leave(sender, e);
}
}
private void afsiChkSalesBaseCostUpdate_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == 11)
{
afsiChkSalesBaseCostUpdate_Leave(sender, e);
}
}
private void afsiChkSalesBaseCostUpdate_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == 11)
{
afsiChkSalesBaseCostUpdate_Leave(sender, e);
}
}
EDIT: Found out that the page is using UltraWinTabControl from Infragistics so maybe this is causing some issues with the tabbing.
I ended up needing to override ProcessCmdKey now I face a new problem that is kind of related but not particular to this so I will add it as a comment if I get my answer.
private bool isTab = false;
private bool isShiftTab = false;
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (keyData == Keys.Tab)
{
isTab = true;
ShiftTab.Append("Tab");
}
else
{
isTab = false;
}
return base.ProcessCmdKey(ref msg, keyData);
}
You will need to have the MultiLine property set to true, and AcceptsTab also set to true.
Or use e.KeyCode instead or e.KeyData, it worked for me
if (e.KeyCode == Keys.Tab | e.KeyData == Keys.Enter)
VS2010 C# .Net 4.1
I am working on a form that the user must select or enter initial data in a ComboBox. Using the code below, which took some time to deduce, I enable the Edit button when the user hits the Tab key if the data is correct, otherwise the button is disabled it moves to the next button.
This code works, but a side effect is that the PreviewKeyDown event reoccurs when I set IsInputKey to true. This calls validation twice. The KeyDown event is only called once, and the IsInputKey is false again on the second call so I do need to check validation again.
I'd like to understand why and possibly avoid it.
private void comboBox1_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e) {
if (e.KeyData == Keys.Tab) {
if (ValidationRoutine()) {
e.IsInputKey = true; //If Validated, signals KeyDown to examine this key
} //Side effect - This event is called twice when IsInputKey is set to true
}
}
private void comboBox1_KeyDown(object sender, KeyEventArgs e) {
if (e.KeyData == Keys.Tab) {
e.SuppressKeyPress = true; //Stops further processing of the TAB key
btnEdit.Enabled = true;
btnEdit.Focus();
}
}
The why? is hard to answer, Winforms just does. First from the message loop, again from the control's message dispatcher. The event was really meant as an alternative way to implement the protected IsInputKey() method without having to override the control class. Bit of a hack, I always override and never used the event.
The better mouse trap is to override ProcessCmdKey() instead. Like this:
protected override bool ProcessCmdKey(ref Message msg, Keys keyData) {
if (this.ActiveControl == comboBox1 && keyData == Keys.Tab) {
if (ValidationRoutine()) {
btnEdit.Enabled = true;
btnEdit.Focus();
return true;
}
}
return base.ProcessCmdKey(ref msg, keyData);
}
In c# I am using this code to imediately react on press keys.
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (keyData == Keys.NumPad1)
{
button_1.PerformClick();
return true;
}
}
I defined this for all numpad numbers and it WORKS great. But I am not able to define this function for (/,,-,+) on NumPad. I have read some topics with solution throw keyCode...it was like if(e.keykode==46) than something. But it worked after i pressed enter. I need imediatly reaction no keys +,-,,/. Can somebody help me pls?
You're looking for Keys.Add, Keys.Divide, Keys.Multiply, and Keys.Subtract, I believe.
To use them, that would be exactly the same as you have already done:
if(keyData == Keys.Multiply) { // or Add, Divide, or Subtract
btnMultiply.PerformClick(); // Or whatever else you want to do here.
}
Do you want this to occur in an event like so:
private void txtText_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Add)
{
//do something
}
}
Something like this should work for you.