SplitContainer, how do stop cursor key input? - c#

I want a c# split container that ignores cursor keys and can only be controlled with the mouse. How can I do this? This is so I can use the keyboard input in one of the side panels without simultaneously moving the split.

Using e.Handled = true or e.SuppressKeyPress = true to prevent the keys from resizing the splitter didn't work for me.
I was able to do it by setting IsSplitterFixed = true on KeyDown, and IsSplitterFixed = false on MouseDown/MouseMove (to allow resizing by mouse).
e.g.
public Form1()
{
InitializeComponent();
splitContainer1.MouseMove += splitContainer1_MouseMove;
splitContainer1.KeyDown += splitContainer1_KeyDown;
splitContainer1.MouseDown += splitContainer1_MouseDown;
}
void splitContainer1_MouseDown(object sender, MouseEventArgs e)
{
splitContainer1.IsSplitterFixed = false;
}
void splitContainer1_MouseMove(object sender, MouseEventArgs e)
{
splitContainer1.IsSplitterFixed = false;
}
void splitContainer1_KeyDown(object sender, KeyEventArgs e)
{
splitContainer1.IsSplitterFixed = true;
}

You may disable the keyboard input handling the KeyDown event of the control and if required, you may handle the event if the input matches specific keys.
Example
splitContainer1.KeyDown += new KeyEventHandler(splitContainer1_KeyDown); //Link the KeyDown event of splitContainer1 to splitContainer1_KeyDown
private void splitContainer1_KeyDown(object sender, KeyEventArgs e)
{
// if (e.KeyCode == Keys.Up || e.KeyCode == Keys.Down || e.KeyCode == Keys.Left || e.KeyCode == Keys.Right) //Continue if one of the arrow keys was pressed
// {
e.Handled = true; //Handle the event
// }
}
Moreover, you may stop the splitter from moving by canceling the SplitterMoving event of the SplitContainer control according to the KeyCode gathered from its KeyDown event
Example
Keys KeyCode; //This is the variable we will use to store the KeyCode gathered from the KeyDown event into. Then, check if it matches any of the arrow keys under SplitterMoving event canceling the movement if the result was true
splitContainer1.KeyDown += new KeyEventHandler(splitContainer1_KeyDown); //Link the KeyDown event of splitContainer1 to splitContainer1_KeyDown
splitContainer1.SplitterMoving += new SplitterCancelEventHandler(splitContainer1_SplitterMoving); //Link the SplitterMoving event of splitContainer1 to splitContainer1_SplitterMoving
private void splitContainer1_SplitterMoving(object sender, SplitterCancelEventArgs e)
{
if (KeyCode == Keys.Up || KeyCode == Keys.Down || KeyCode == Keys.Left || KeyCode == Keys.Right) //Continue if one of the arrow keys was pressed
{
KeyCode = Keys.A; //Reset the KeyCode
e.Cancel = true; //Cancel the splitter movement
}
}
private void splitContainer1_KeyDown(object sender, KeyEventArgs e)
{
KeyCode = e.KeyCode; //Set KeyCode to the KeyCode of the event
// e.Handled = true; //Handle the event
}
Thanks,
I hope you find this helpful :)

Related

How to prevent call several KeyDown events by pressing a single key on the keyboard?

I have set KeyPreview property of the form to true in order to call keyboard events of the form before control events.
Both the form and the control in the form have KeyDown event like:
form:
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.Control && (e.KeyCode == Keys.Enter || e.KeyCode == Keys.Return)) {
MessageBox.Show("Control + Enter (Form)");
}
}
control:
private void TextBox1_KeyDown(object sender, KeyEventArgs e)
{
if (!e.Control && (e.KeyCode == Keys.Enter || e.KeyCode == Keys.Return)) {
MessageBox.Show("Control + Enter (TextBox)");
}
}
As you see the difference between these two parts of code is that in the form event code I need to call the KeyDown event when the user presses CTRL and Enter keys at the same time,
In the TextBox event code, I need to call the event when the user presses Enter key without holding CTRL-key.
The problem is that when I press Ctrl and Enter keys at the same time both of the above events will call.
How to prevent call both events?
I suggest you use the textBox1_KeyUp event. You can refer to the following code. My test was successful.
public Form1()
{
InitializeComponent();
this.KeyPreview = true;
}
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.Control && (e.KeyCode == Keys.Enter || e.KeyCode == Keys.Return))
{
MessageBox.Show("Control + Enter (Form)");
}
}
private void textBox1_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Control)
{
e.Handled = true;
}
else if (e.KeyCode == Keys.Enter)
{
MessageBox.Show("Control + Enter (TextBox)");
}
}
Use the ProcessCmdKey and like this.
protected override bool ProcessCmdKey(ref Message msg, System.Windows.Forms.Keys keyData)
{
int WM_ALRT_DOWN = 0x0104;
int WM_KEYDOWN = 0x0100;
if (msg.Msg == WM_ALRT_DOWN && (int)msg.WParam == (int)Keys.F4) //Alt + F4
{
return true; // The key is manually processed
}
if (msg.Msg == WM_KEYDOWN && (int)msg.WParam == (int)Keys.Escape) //Esc
{
return true; // The key is manually processed
}
if (msg.Msg == WM_KEYDOWN && (int)msg.WParam == (int)Keys.Space) //Space
{
return true; // The key is manually processed
}
}

How to detect a custom key from Keyboard using C#

I have a USB Keyboard that have some Special keys like "FN",PLAY,MUTE and one that changes the keyboard light. I was trying to get what is this key "name" to perform a logic to change the color periodically.
private void textBox1_TextChanged(object sender, EventArgs e)
{
var key = sender as TextBox;
var result = key.Text;
}
But the key its not a string to be recognized. How can I do this ? Thanks!
I will suggest you to use OnKeyPress and OnKeyDown events instead to check what was pressed. MSDN Link.
Example:
// Boolean flag used to determine when a character other than a number is entered.
private bool nonNumberEntered = false;
// Handle the KeyDown event to determine the type of character entered into the control.
private void textBox1_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
{
// Initialize the flag to false.
nonNumberEntered = false;
// Determine whether the keystroke is a number from the top of the keyboard.
if (e.KeyCode < Keys.D0 || e.KeyCode > Keys.D9)
{
// Determine whether the keystroke is a number from the keypad.
if (e.KeyCode < Keys.NumPad0 || e.KeyCode > Keys.NumPad9)
{
// Determine whether the keystroke is a backspace.
if(e.KeyCode != Keys.Back)
{
// A non-numerical keystroke was pressed.
// Set the flag to true and evaluate in KeyPress event.
nonNumberEntered = true;
}
}
}
//If shift key was pressed, it's not a number.
if (Control.ModifierKeys == Keys.Shift) {
nonNumberEntered = true;
}
}
// This event occurs after the KeyDown event and can be used to prevent
// characters from entering the control.
private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
// Check for the flag being set in the KeyDown event.
if (nonNumberEntered == true)
{
// Stop the character from being entered into the control since it is non-numerical.
e.Handled = true;
}
}

How to capture Ctrl-Z keystroke in a RichTextBox

I need to capture when the user presses CTRL-Z (press CTRL and Z at the same time) in a RichTextBox control.
I've turned off the ShortCutsEnabled property. I've tried every combination I can think of using KeyCode and KeyData with the KeyDown and KeyPress events.
I can capture EITHER a CTRL OR a Z, but never both together. Is RichTextBox capturing this keystroke before I can see it, even if shortcuts are disabled?
Does anyone have a solution that works for this?
you could simply use CTRL-Z
textBox1.KeyDown += new KeyEventHandler(textBox1_KeyDown);
void textBox1_KeyDown(object sender, KeyEventArgs e)
{
if(e.KeyCode == Keys.Z && (e.Control)) {
MessageBox.Show("Ctrl + Z Pressed!");
}
}
Check KeyCode and Modifiers in the KeyDown event:
private void richTextBox1_KeyDown(object sender, KeyEventArgs e)
{
if (e.Modifiers == Keys.Control && e.KeyCode == Keys.Z)
MessageBox.Show("Ctrl-Z Pressed");
}
void richTextBox1_KeyDown(object sender, KeyEventArgs e)
{
if ((Control.ModifierKeys & Keys.Control) == Keys.Control && e.KeyCode == Keys.Z)
{
MessageBox.Show("Ctrl + Z is Pressed");
}
}
try this.

Why does my KeyPressEvent not work with Right/Left/Up/Down?

In C#, I am trying to see if the user presses the right key so that a player moves right, but when I try it, it does not register the keypress:
private void KeyPressed(object sender, KeyPressEventArgs e)
{
if(e.KeyChar == Convert.ToChar(Keys.Right))
{
MessageBox.Show("Right Key");
}
}
It does not display the MessageBox
This doesn't work for Left/Up/Down either
However, if I replace it with
if(e.KeyChar == Convert.ToChar(Keys.Space))
It works.
Am I doing something wrong?
You should use KeyDown event, e.g. for arrows:
private void KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Down || e.KeyCode == Keys.Up || e.KeyCode == Keys.Left || e.KeyCode == Keys.Right)
{
}
}
Arrow keys are not characters, so KeyPressed is not used for them.
Arrow Keys are in keyUp event they are:
Keys.Up, Keys.Down, Keys.Left, Keys.right
They are not triggered by KeyPressEventArgs.

Does the KeyDown KeySuppress cancel KeyUp event?

Let's say I've got this:
private void txtAnalogValue_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
//Non-numeric key pressed => prevent this from being input into the Textbox
e.SuppressKeyPress = true;
}
}
and this:
private void txtAnalogValue_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
try
{
UpdateState(double.Parse(((TextBox)sender).Text));
}
catch (Exception ex)
{
((TextBox)sender).Text = ioElement.StateVal.ToString("0.00");
}
}
}
I know this code doesn't make a lot of sense, it's just test.
The question is: Will the e.SuppressKeyPress = true in KeyDown event have affect on KeyUp event, so the Enter key will not be accepted?
No, e.SuppressKeyPress = true will just ignore the Enter key (it won't go to the next line and Text property of the textbox won't be changed) and e.Keycode will be visible in the KeyUp. Therefore suppressing the key in the KeyDown doesn't affect the KeyUp event and your code should work. The UpdateState will be called when you hit Enter button in the TextBox. You can try this code to check it:
private void txtAnalogValue_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.A)
{
e.SuppressKeyPress = true;
}
}
private void txtAnalogValue_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.A)
{
MessageBox.Show("Up");
}
}

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