[WinUI3] How to disable input methods when using TextBox?

Question

I want the TextBox to only be able to enter letters from the keyboard.And disable input methods.
I have tried the following methods:
~~~
ImmAssociateContext(main_window_hwnd, NULL);
~~~
but failed to disable successfully. Is the "main_window_hwnd" error? And I want to know how to get the right hwnd.

I also tried to intercept 'PreviewKeyDown'.It failed too.

I also know we can use “InputMethod” to Implement this in wpf，but what is the corresponding method in winui3?

Answer 1

I did some tests and this one worked, on Windows 10 21H1, not sure for other OS =>

(in MainWindow constructor)

IntPtr hWnd = WinRT.Interop.WindowNative.GetWindowHandle(this);  
IntPtr pContext = ImmGetContext(hWnd);  
bool bRet = ShowReadingWindow(pContext, false);  

with declarations :

    [DllImport("Imm32.dll", SetLastError = true, CharSet = CharSet.Unicode)]  
    public static extern IntPtr ImmGetContext(IntPtr unnamedParam1);  

    [DllImport("CHxReadingStringIME.dll", SetLastError = true, CharSet = CharSet.Unicode)]  
    public static extern bool ShowReadingWindow(IntPtr hwnd, bool bShow);

Answer 2

Hello,
Welcome to Microsoft Q&A!

How to disable input methods when using TextBox?

I think you could use PreviewKeyDown evnet to disable textbox input, PreviewKeyDown contains KeyRoutedEventArgs, you could set set the handler as true to disable keyboard input

private void TextBox_PreviewKeyDown(object sender, KeyRoutedEventArgs e)  
{  
    e.Handled = true;  
}  

Is the "main_window_hwnd" error? And I want to know how to get the right hwnd.

In WinUI3 we have provide way to Retrieve a window handle, please refer to Retrieve a window handle (HWND) official document.

The C# code below shows how to retrieve the window handle (HWND) for a WinUI 3 Window object.

private async void myButton_Click(object sender, RoutedEventArgs e)  
{  
    // Retrieve the window handle (HWND) of the current WinUI 3 window.  
    var hWnd = WinRT.Interop.WindowNative.GetWindowHandle(this);  
}  

Thank you.

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Answer 3

How about disabling the textbox???
For Ex: If the text box name is 'txt_name'. Then the to disable it just use the code = txt_name.isEnabled = false;
and to enable it back = txt_name.isEnabled = true;