I'm asking the question already asked (and even answered) here:
Why are some textboxes not accepting Control + A shortcut to select all by default
But that answer doesn't work for me. I have this code:
public class LoginForm : Form
{
private TextBox tbUsername;
public LoginForm()
{
tbUsername = new TextBox();
tbUsername.ShortcutsEnabled = true;
tbUsername.Multiline = false;
Controls.Add(tbUsername);
}
}
The textbox shows up, I can write on it, I can cut, copy and paste text on it without any problems.
But when I try to press Ctrl+A I only hear a "bling" similar to the bling that you hear if you try to erase text from an empty textbox (try it with your browser's address bar).
Like other answers indicate, Application.EnableVisualStyles() should be called. Also the TextBox.ShortcutsEnabled should be set to true. But if your TextBox.Multiline is enabled then Ctrl+A will not work (see MSDN documentation). Using RichTextBox instead will get around the problem.
Just create a keydown event for that TextBox in question and include this code:
private void tbUsername_KeyDown(object sender, KeyEventArgs e)
{
if (e.Control && e.KeyCode == Keys.A)
{
if (sender != null)
((TextBox)sender).SelectAll();
}
}
You could always override the process command keys to get the desired result
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
const int WM_KEYDOWN = 0x100;
var keyCode = (Keys) (msg.WParam.ToInt32() &
Convert.ToInt32(Keys.KeyCode));
if ((msg.Msg == WM_KEYDOWN && keyCode == Keys.A)
&& (ModifierKeys == Keys.Control)
&& tbUsername.Focused)
{
tbUsername.SelectAll();
return true;
}
return base.ProcessCmdKey(ref msg, keyData);
}
Quick answer is that if you are using multiline true you have to explicitly call the select all.
private void tbUsername_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.A && e.Control)
{
tbUsername.SelectAll();
}
}
This happened to me once too, I'm assuming you removed the call for Application.EnableVisualStyles(); from your program? Add it back to the Main() function and everything should work fine.
Textbox has a method SelectAll() and worked well for me. (.net 4.5)
No need to handle WM_KEYDOWN! I know that most examples here (and CodeProject and many other places) all say there is, but it does not cure the beep that results whenever a WM_CHAR arises that is not handled.
Instead, try this:
LRESULT CALLBACK Edit_Prc(HWND hwnd,UINT msg,WPARAM wParam,LPARAM lParam){
if(msg==WM_CHAR&&wParam==1){SendMessage(hwnd,EM_SETSEL,0,-1); return 1;}
else return CallWindowProc((void*)WPA,hwnd,msg,wParam,lParam);
}
Remember to subclass the EDIT control to this Edit_Prc() using WPA=SetWindowLong(...) where WPA is the window procedure address for CallWindowProc(...)
I figured this out by experiment, after finding that all the answers I found online insisted on handling WM_KEYDOWN, using GetKeyState(), and ended up with bigger code that failed to stop that annoying beep!
While this answer doesn't deal with dotnet, in cases like this it's usually better to cut to the chase and solve it rather than agonise over which version of a large code wrapper system may or may not do it for you, especially if you want to avoid the risk of fighting against inbuilt behaviour.
Throwing in my two cents. Calling this under keypress is just another option.
private void TxtBox_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == '\x1')
{
TxtBox.SelectAll();
e.Handled = true;
}
}
This is my code, it is working fine
private void mainSimPlus_KeyDown(object sender, KeyEventArgs e)
{
e.Handled = true;
if (e.Control == true && e.KeyCode == Keys.A)
{
if (SelectAllTextBox(txt1))
return;
if (SelectAllTextBox(txt2))
return;
}
}
private bool SelectAllTextBox(TextBox txt)
{
if (txt.Focused)
{
txt.SelectAll();
return true;
}
else
return false;
}
Related
private void UserInputText_KeyDown(object sender, KeyEventArgs e)
{
if ((e.KeyCode == Keys.D4 && e.Modifiers == Keys.Shift) || (e.KeyCode == Keys.Add))
{
if (String.IsNullOrEmpty(UserInputText.Text))
{
MessageBox.Show("Bir sayı giriniz.");
UserInputText.Clear();
return;
}
if (double.TryParse(UserInputText.Text, out sayı1))
{
CalculationResultText.Text = sayı1 + " + ";
islem = "+";
UserInputText.Clear();
}
else
{
MessageBox.Show("Sadece sayı değeri girebilirsiniz.");
UserInputText.Clear();
}
}
}
I am coding a basic forms calculator. I am trying to trigger addition function and clear the textbox when textbox is focused and user presses "+" key. "if (String.IsNullOrEmpty(UserInputText.Text)) and else conditions work well. But if no Message boxes shows up as in the
if (double.TryParse(UserInputText.Text, out sayı1)) condition, the "+" character remains in the textbox as in the image. Thanks for help.
If I understand correctly, you want to first check the character that was typed in and if it's incorrect then you want to prevent this character from appearing?
If so, then you need to set e.Handled = true property when you want to prevent it.
This call tells the GUI element (your TextBox) that "I did all the checks for this event (i.e. KeyDown event), and I don't want you to contribute in handling of this event (i.e. normally the TextBox would try to add this character to its Text property, but you prevent it)".
Check out documentation on KeyEventArgs.Handled.
KeyPress event enables you to prevent any further changes in the TextBox.
You can do that thanks to Handled property of KeyPressEventArgs
private void UserInputText_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == '+')
{
UserInputText.Clear();
e.Handled = true;
}
}
my code is :
private void richTextBox1_KeyDown(object sender, KeyEventArgs e)
{
if ((e.Key==Key.LeftCtrl && e.Key==Key.C) || (e.Key==Key.RightCtrl && e.Key==Key.C))
{
MessageBox.Show("Copy not allowed !");
e.Handled = true;
}
}
or , another way , i have tried is :
private void richTextBox1_KeyDown(object sender, KeyEventArgs e)
{
if ((e.Key==Key.C) && (Keyboard.Modifiers==ModifierKeys.Control))
{
MessageBox.Show("Copy not allowed !");
e.Handled = true;
}
}
But they do not work !
Please do not tell me to set Focusable="False" or IsHitTestVisible="False"
because after that , i can not use scrollbar !
Please help.
thanks.
You can handle the PreviewKeyDown event... you almost had it, you just needed to and (&) the Keyboard.Modifiers because it could contain more than just ModifierKeys.Control:
private void PreviewKeyDown(object sender, KeyEventArgs e)
{
if (e.Key == Key.C && (Keyboard.Modifiers & ModifierKeys.Control) ==
ModifierKeys.Control)
{
MessageBox.Show("CTRL + C was pressed");
}
}
I assume your problem is not really how to disable ctrl+A and ctrl+C, just because you don't want the user to do exactly that, but to prevent the user from copying the content of the text box. Problem is, Ctrl+A Ctrl+C is not the only way to copy data. The user could select the text, and right click.
So what you should do then is not to override the keystroke, but the actual command that is being fired. (You may want to read up on how Commands works in WPF.)
To do that, simply add the following method to your class
private void CancelCopyCommand(object sender, DataObjectEventArgs e)
{
MessageBox.Show("Copy not allowed !");
e.CancelCommand();
}
And in the Constructor, register the command as follow:
DataObject.AddCopyingHandler(richTextBox1, CancelCopyCommand);
A richTextbox is for entering Text, ok you can make it readonly, so why do you want to prevent copy?
Try using Images to prevent copy, or disable focusing/selecting. If the user selects Text, destroy the selection.
You have to subscribe for the PreviewKeyDown-Event and in the Handler you have to set e.Handled = true if your Key-Combination was pressed.
I want to give a textbox focus when the user starts typing anywhere in my app.
My page inherits from LayoutAwarePage.
Can this be achieved ?
Edit:
I got this code:
// In constructor
Window.Current.CoreWindow.KeyDown += CoreWindow_KeyDown;
// Somewhere else in class
void CoreWindow_KeyDown(Windows.UI.Core.CoreWindow sender, Windows.UI.Core.KeyEventArgs args)
{
this.setSearchboxFocus((int)args.VirtualKey);
}
private void setSearchboxFocus(int keyCode)
{
if (keyCode == 38)
return;
if (keyCode == 40)
return;
if (this.searchBox.FocusState == Windows.UI.Xaml.FocusState.Unfocused)
{
this.searchBox.Text = "";
this.searchBox.Focus(Windows.UI.Xaml.FocusState.Keyboard);
}
}
For anyone reading this thread in the future, it is because of the webview. I asked a similar question on the msdn forum here. As of Windows 8.1, the webview is implemented as a separate window and completely steals all keyboard input when it has focus without passing any of it up to the controlling application. If you are able to change the HTML in the website being called it may be possible to use javascript listeners to pass events between the application and webview, but I did not test this myself. Unfortunately there does not seem to be any other workaround at this time.
You can handle the KeyDown/KeyUp event for the whole page by subscribing to these events
Window.Current.CoreWindow.KeyDown += CoreWindow_KeyDown;
Window.Current.CoreWindow.KeyUp += CoreWindow_KeyUp
This might help
private void Form1_KeyPress(object sender, KeyPressEventArgs e)
{
textBox1.Focus();//sets focus to textBox1 when user presses a key on form
}
How about something like this?
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (!textBox1.Focused)
{
textBox1.Focus();
return true;
}
return base.ProcessCmdKey(ref msg, keyData);
}
How about, on the Windows.UI.Xaml.Controls.Page:
protected override void OnKeyDown(KeyRoutedEventArgs e)
{
textBox1.Focus(Windows.UI.Xaml.FocusState.Keyboard);
base.OnKeyDown(e);
}
This is not a duplicate. Many similar threads discuss capturing a combination involving a modifier key.
I need to get something triggered when a shortcut key (a combination of Insert+Tab) is pressed from a control, say Button.
Catch:
This involves no modifier key like Alt or Shift for which .NET has built in checking.
This has Tab key which is not caught so easily.
What I tried and came close:
1) KeyDown Event but doesnt capture Tabs..
[DllImport("user32.dll")]
public static extern int GetKeyboardState(byte[] keystate);
static void form_KeyDown(object sender, KeyEventArgs e)
{
if (!(((Form)sender).ActiveControl is Button))
return;
byte[] keys = new byte[255];
GetKeyboardState(keys);
if (keys[(int)Keys.Insert] == 129 && keys[(int)Keys.Tab] == 129)
{
// doesn't work
}
if (keys[(int)Keys.Insert] == 129 && keys[(int)Keys.J] == 129)
{
// works, since here this doesnt involve Tab
}
}
This works with regular combinations, doesnt fire along with Tab.
2) KeyPreview Event which captures Tab key, but I do not know how to get a combination of keys pressed
static void form_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
if (!(((Form)sender).ActiveControl is Button))
return;
if (e.KeyCode == Keys.Tab)
//works
if (e.KeyCode == Keys.Insert && e.KeyCode == Keys.Tab)
//doesn't hit.
}
Requirement:
1) I am not registering the event from Form class. Instead I have a utility class which creates all required events (along with other shortcuts). I just pass the instance of form to a static function. So I am quite unsure how I should utilize the various key overriding calls. Here is how I do it:
public frmLogin()
{
InitializeComponent();
Utility.SetFormEvents(this);
}
static void SetFormEvents(Form f){
//foreach control...........
}
But I can give up on this..
Thanks..
Tab is considered a command key, you don't actually get notified of it being pressed directly. You could PInvoke the GetKeyState method, but I think it's just easier to recognize that tab is a command key (and override ProcessCmdKey) and keep track of whether the Insert key is up or down. For example:
static bool insertPressed;
static bool tabPressed;
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if(keyData == Keys.Tab)
{
tabPressed = true;
CheckForTabAndInsert();
}
return base.ProcessCmdKey(ref msg, keyData);
}
static void form_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Insert)
{
insertPressed = true;
CheckForTabAndInsert();
insertPressed = false;
}
}
static void form_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Insert) insertPressed = false;
}
The drawback is that you only really get a KeyPress for tab with ProcessCmdKey, so you can only really support Insert+Tab (not Tab+Insert). This is because Tab is used to switch context from one control to another. Depending on your situation (i.e. in the context of a text box), you could make use of the AcceptTab property to possibly just use KeyUp and KeyDown... But, from what you posted, that doesn't appear to be the case.
I have a textbox on a form where I'm trying to detect the keys the user types in. The TextBox is multilined with wordwrap on. I don't want the user the press the enter key (as I want all text entered on ONE line, wrapped) so I used the following code:
private void txtPlain_KeyPress(object sender, KeyPressEventArgs e) {
if (e.KeyChar == (char)13) {
MessageBox.Show("Enter keys are not allowed");
e.KeyChar = (char)0;
}
}
This worked fine in my tests, but when I tested for CTRL+ENTER it didn't work as I'm not sure how to detect for the control key. From my googling I found that I need to use the KeyUp/Down events so I now have the following Code:
private void txtPlain_KeyUp(object sender, KeyEventArgs e) {
//if (e.KeyData == (Keys.Control | Keys.Enter)) {
if (e.KeyCode == Keys.Enter || (e.KeyCode == Keys.Enter && e.Control)) {
MessageBox.Show("Enter keys are not allowed:");
//e.KeyValue = Keys.None;
}
}
The first commented out line didn't work for some reason so if anyone could explain why this would be useful.
The problem with the KeyUp/Down event is that I don't know how to REMOVE the enter key from the text - unlike the KeyPress event when I can set the KeyChar to zero. The event captures both the Enter and Ctrl+Enter keys, but the cursor still goes to the next line in the TextBox.
Thanks for any help on this.
Hmm, there's no reason to disallow the Enter key by handling the KeyDown or KeyUp events. You can simply set the AcceptsReturn property of the textbox control to False. This will prevent a multiline textbox from responding to a press of the Enter key.
Of course, this doesn't solve the problem of Ctrl+Enter. In fact, that's the expected way to create a new line when the AcceptsReturn property is set to False. To solve that, you will need to handle one of the keyboard events and prevent the control from receiving this input.
KeyDown is a good place to start. What you want to do is filter out any keyboard events that include the Keys.Enter flag. That will catch them no matter which other modifier key they might be combined with. Then, once you've found an Enter keypress, you want to set the e.Handled property to True in order to prevent it from being passed on to the control.
But unfortunately, we're not quite done yet. The textbox control tries to handle certain keys internally, and you're not going to be able to override that in a key event handler method. You also need to tell the control not to interpret that particular key as an input key. There are two primary ways of doing this. The first (and recommended way) is to inherit from the base TextBox class to create your own custom control, and then override the protected IsInputKey method. The second (somewhat simpler) way is just to handle the PreviewKeyDown event, and set the IsInputKey property to False.
Sample code:
private void txtPlain_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
// Check if the KeyCode value has the Keys.Enter flag set
if ((e.KeyCode & Keys.Enter) == Keys.Enter)
{
// Set the IsInputKey property to False
e.IsInputKey = false;
}
}
private void txtPlain_KeyDown(object sender, KeyEventArgs e)
{
// Check if the KeyCode value has the Keys.Enter flag set
if ((e.KeyCode & Keys.Enter) == Keys.Enter)
{
// Show the user a message
MessageBox.Show("Enter keys are not allowed in this textbox.");
// Prevent the key event from being passed on to the control
e.Handled = true;
}
}
And, though I assume this is for testing purposes only, you definitely want to take that MessageBox call out of there for production code. Find another way to alert the user that their input was not allowed, such as a short beep sound and an ErrorProvider component placed next to the textbox. Showing a message box is very jarring, and not very user-friendly. See my answer here for other hints and tips.
private void txtPlain_KeyUp(object sender, KeyEventArgs e) {
//if (e.KeyData == (Keys.Control | Keys.Enter)) {
if (e.KeyCode == Keys.Enter || (e.KeyCode == Keys.Enter && e.Control)) {
MessageBox.Show("Enter keys are not allowed:");
//e.KeyValue = Keys.None;
// mark event as handled
e.Handled = true;
}
}
from msdnlink
edit:
I think that you need the key down event not the key up
EDIT2
here is some tested code and it works as you wanted:
bool invalid=false;
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
if ((e.KeyCode & Keys.Enter) == Keys.Enter)
{
invalid = true;
}
}
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (invalid)
{
e.Handled = true;
}
invalid = false;
}
The first commented out line didn't work for some reason so if anyone could explain why this would be useful.
You wanted to detect Ctrl + Enter.
if (e.KeyData == (Keys.Control | Keys.Enter)) {..
Keys.Control and Key.Enter are nothing but are some values please refer . Now doing logical or will not necessarily result to key which has been pressed. Totally illogical clause.
Ok now come to your actual problem you want to detect Enter stroke and Ctrl + Enter stroke to be treated as same.
Besides you want to undo the newline character thats been introduced. Try
PreviewKeyDown or Preview key up eventhandler with the following condition
if(e.KeyCode==Keys.Enter)
Let me know if this works