I need to disable changing focus with arrows on form. Is there an easy way how to do it?
Thank you
Something along the lines of:
private void Form1_Load(object sender, EventArgs e)
{
foreach (Control control in this.Controls)
{
control.PreviewKeyDown += new PreviewKeyDownEventHandler(control_PreviewKeyDown);
}
}
void control_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
if (e.KeyCode == Keys.Up || e.KeyCode == Keys.Down || e.KeyCode == Keys.Left || e.KeyCode == Keys.Right)
{
e.IsInputKey = true;
}
}
I've ended up with the code below which set the feature to EVERY control on form:
(The code is based on the one from andynormancx)
private void Form1_Load(object sender, EventArgs e)
{
SetFeatureToAllControls(this.Controls);
}
private void SetFeatureToAllControls(Control.ControlCollection cc)
{
if (cc != null)
{
foreach (Control control in cc)
{
control.PreviewKeyDown += new PreviewKeyDownEventHandler(control_PreviewKeyDown);
SetFeatureToAllControls(control.Controls);
}
}
}
void control_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
if (e.KeyCode == Keys.Up || e.KeyCode == Keys.Down || e.KeyCode == Keys.Left || e.KeyCode == Keys.Right)
{
e.IsInputKey = true;
}
}
I tried this aproach, where the form handles the preview event once. It generates less code than the other options.
Just add this method to the PreviewKeyDown event of your form, and set the KeyPreview property to true.
private void form1_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
switch (e.KeyCode)
{
case Keys.Up:
case Keys.Down:
case Keys.Left:
case Keys.Right:
e.IsInputKey = true;
break;
default:
break;
}
}
You should set KeyPreview to true on the form. Handle the KeyDown/KeyUp/KeyPress event and set the e.Handled in the eventhandler to true for the keys you want to be ignored.
Related
I was hoping that this code below would overwrite it, since I am assigning new stuff. But instead it executes both, selecting all and my message box
private void EventSetter_OnHandler(object sender, KeyEventArgs e)
{
if (e.Key == Key.A && (Keyboard.IsKeyDown(Key.LeftCtrl) || Keyboard.IsKeyDown(Key.RightCtrl)))
{
System.Windows.MessageBox.Show("ctrl a");
}
}
please help thanks
If you handle the PreviewKeyDown event for the ListBox, you should be able to mark the event as handled, and the Ctrl+A should be ignored:
private void OnListBoxKeyDown(object sender, KeyEventArgs e)
{
if (e.Key == Key.A && (Keyboard.IsKeyDown(Key.LeftCtrl) || Keyboard.IsKeyDown(Key.RightCtrl)))
{
e.Handled = true;
}
}
I have a textbox with a OnKeyPress event. In this textbox I wish to input only numbers, and for some specific letters like t or m, I would want to execute a code without that letter being typed in the textbox. Small sample of what I am trying to do:
//OnKeyPressed:
void TextBox1KeyDown(object sender, KeyEventArgs e)
{
if(e.KeyCode == Keys.T || e.KeyCode == Keys.M) Button1Click(this, EventArgs.Empty);
}
This unfortunately does not prevent the input of the letter..
Set the SuppressKeyPress property from KeyEventArgs to true, like below:
private void TextBox1KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.T || e.KeyCode == Keys.M)
{
e.SuppressKeyPress = true;
Button1Click(this, EventArgs.Empty);
}
}
You could always run the TryParse on the keyDown event so as to validate as the data gets entered. It saves the user an additional UI interaction.
private void TextBox1KeyDown(object sender, KeyEventArgs e)
{
int i;
string s = string.Empty;
s += (char)e.KeyValue;
if (!(int.TryParse(s, out i)))
{
e.SuppressKeyPress = true;
}
else if(e.KeyCode == Keys.T || e.KeyCode == Keys.M)
{
e.SuppressKeyPress = true;
Button1Click(this, EventArgs.Empty);
}
}
I am trying to use the KeyDown-Event (because I like to use KeyCode) to make a single action happen. For this purpose I am using a bool variable to stop continuous actions.
Can't figure out what's wrong with my code though, and haven't found a comparable problem/solution yet...
There are 2 tabs on my tabcontrol and i want to be able to switch between them using CTRL+TAB.
The switching should happen ONCE on keydown of tab.
bool tabSwitchPossible = true;
void Form1_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Tab)
tabSwitchPossible = true; //Reset boolean
}
void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (tabSwitchPossible && e.KeyCode == Keys.Tab && e.Modifiers == Keys.Control)
{
tabSwitchPossible = false; //Set boolean to prevent further action
if (mainTabControl.SelectedIndex >= mainTabControl.TabCount - 1)
mainTabControl.SelectedIndex = 0;
else
mainTabControl.SelectedIndex++;
return;
}
}
Is there an automatic KeyUp event fired, even when i don't release the key?!
Thanks, in advance guys...
You don't need to handle Form1_KeyUp and tabSwitchPossible varible, remove it and just copy the following code:
void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Tab && e.Modifiers == Keys.Control)
{
if (mainTabControl.SelectedIndex >= mainTabControl.TabCount - 1)
mainTabControl.SelectedIndex = 0;
else
mainTabControl.SelectedIndex++;
}
}
During the initial development of my .NET application (using WinForms), I had to go in and create common editing shortcuts such as CTRL-A, CTRL-C, and CTRL-V because they are not enabled by default. Now that my application has grown to quite a few text boxes, I am trying to figure out how to refactor the following code. Can someone help please?
private void textBox1_results_KeyDown(object sender, KeyEventArgs e)
{
if (e.Control && e.KeyCode == Keys.A)
{
textBox1_results.SelectAll();
e.SuppressKeyPress = true;
}
if (e.Control && e.KeyCode == Keys.C)
{
textBox1_results.Copy();
e.SuppressKeyPress = true;
}
if (e.Control && e.KeyCode == Keys.V)
{
textBox1_results.Text = Clipboard.GetText();
e.SuppressKeyPress = true;
}
}
If you have a BaseForm that all your forms inherit from try moving the above code to it and call it from all the text box event handlers.
public partial class Form2 : Form1
{
public Form2()
{
InitializeComponent();
}
private void Form2_Load(object sender, EventArgs e)
{
}
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
base.TextKeyDown(sender, e);
}
}
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public void TextKeyDown(object sender, KeyEventArgs e)
{
if (e.Control && e.KeyCode == Keys.A)
{
((TextBox) sender).SelectAll();
e.SuppressKeyPress = true;
}
if (e.Control && e.KeyCode == Keys.C)
{
((TextBox)sender).Copy();
e.SuppressKeyPress = true;
}
if (e.Control && e.KeyCode == Keys.V)
{
((TextBox)sender).Text = Clipboard.GetText();
e.SuppressKeyPress = true;
}
}
}
Well, there are two main approaches to this.
Create your own text box control by inheriting from System.Windows.Forms.TextBox and adding your own implementation of the KeyDown (still calling base.KeyDown()) with the short cuts enabled
Create a helper class that you call in each form's Load even that iterates through all controls on the form and adds a handler to your code.
Option 1 would be something like;
public class ShortcutTextBox : TextBox
{
protected override void OnKeyDown(KeyEventArgs e)
{
if (e.Control && e.KeyCode == Keys.A)
{
SelectAll();
e.SuppressKeyPress = true;
}
else if (e.Control && e.KeyCode == Keys.C)
{
Copy();
e.SuppressKeyPress = true;
}
else if (e.Control && e.KeyCode == Keys.V)
{
Text = Clipboard.GetText();
e.SuppressKeyPress = true;
}
base.OnKeyDown(e);
}
}
Though this comes with the caveat that you'd need to replace every instance of TextBox with ShortcutTextBox.
Option two still involves refactoring but it's a once per form option. Create a helper class like the following;
public abstract class ControlUtilities
{
public static void AddTextBoxShortcuts(Control.ControlCollection controls)
{
foreach (Control c in controls)
{
if (c is TextBox)
{
TextBox txt = (TextBox)c;
txt.KeyDown += textBox_KeyDown;
}
else if (c.Controls != null && c.Controls.Count > 0)
{
// recursively look for text boxes
AddTextBoxShortcuts(c.Controls);
}
}
}
private static void textBox_KeyDown(object sender, KeyEventArgs e)
{
TextBox txt = (TextBox)sender;
if (e.Control && e.KeyCode == Keys.A)
{
txt.SelectAll();
e.SuppressKeyPress = true;
}
else if (e.Control && e.KeyCode == Keys.C)
{
txt.Copy();
e.SuppressKeyPress = true;
}
else if (e.Control && e.KeyCode == Keys.V)
{
txt.Text = Clipboard.GetText();
e.SuppressKeyPress = true;
}
}
}
and call it in your form's Load event like;
private void Form1_Load(object sender, EventArgs e)
{
ControlUtilities.AddTextBoxShortcuts(this.Controls);
}
Probably something like this:
private static void Shortcut_KeyDown(object sender, KeyEventArgs e)
{
var textBox = (TextBox)sender;
if (e.Control && e.KeyCode == Keys.A)
{
textBox.SelectAll();
e.SuppressKeyPress = true;
}
if (e.Control && e.KeyCode == Keys.C)
{
textBox.Copy();
e.SuppressKeyPress = true;
}
if (e.Control && e.KeyCode == Keys.V)
{
textBox.Text = Clipboard.GetText();
e.SuppressKeyPress = true;
}
}
And apply it:
textBox1.KeyDown += Shortcut_KeyDown;
textBox2.KeyDown += Shortcut_KeyDown;
// etc...
Although I'm not sure why you would need to write this at all - this behavior is standard to Winforms TextBox as far as I know.
I am working on a CustomControl and I want to register ModifierKeys in this control. I have already set the KeyPerview to True in the Form which this control is being added to.
Now I have a Boolean named _ctrl and I want this boolean to be true when the Control key is being held down and it should be false when Control key is being released.
I tried to achive this with the conde belowe in my CustomControl but no success!
private bool _ctrl = false;
private void MyCustomControl_KeyDown(object sender, KeyEventArgs e)
{
if(e.KeyCode == Keys.Control)
{
_ctrl = true;
}
}
private void MyCustomControl_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Control)
{
_ctrl = false;
}
}
Any tips/soloution will be appriciated!
UPDATE
Ok, I decided to do the key down and up event in the form itself:
private void MainForm_KeyDown(object sender, KeyEventArgs e)
{
if (e.Modifiers == Keys.Control)
{
projectBrowser.ControlKeyIsDown = true; //bool in MyCustomControl
MessageBox.Show("CTRL is PRESSED");
}
}
private void MainForm_KeyUp(object sender, KeyEventArgs e)
{
if (e.Modifiers == Keys.Control)
{
projectBrowser.ControlKeyIsDown = false; //bool in MyCustomControl
MessageBox.Show("CTRL is DEPRESSED");
}
}
Now, The KeyDown event detects the control key and messagebox is being shown. But the KeyUp event does not work and it doesn't show the messagebox. What could be wrong?
It seems that the key up gets detected if I change the KeyUpevent like this:
private void MainForm_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.LControlKey || e.KeyCode == Keys.RControlKey || e.KeyCode == Keys.ControlKey || e.KeyCode == Keys.Control)
{
projectBrowser.ControlKeyIsDown = false;
e.Handled = true;
}
}
You can try calling the Control.ModifierKeys property:
protected override void OnKeyDown(KeyEventArgs e) {
if (Control.ModifierKeys == Keys.Control) {
MessageBox.Show("I am pressing control.");
}
base.OnKeyDown(e);
}
If you throw up a MessageBox on the KeyDown event, the KeyUp event won't get called.