The TextBox process IME input with delay in Korean

• .NET Core Version: Microsoft.NETCore.App 3.1.9
• Windows version: 2004
• Does the bug reproduce also in WPF for .NET Framework 4.8?: Yes
• Is this bug related specifically to tooling in Visual Studio (e.g. XAML Designer, Code editing, etc…)? No

Problem description: Hi, when I place the TextBox inside the popup, it will input the letter only when the next letter is entered. Please take a look at the gif https://i.imgur.com/z9fNvHE.gif .

Actual behavior: The letter was inputted only then I pressed the next key. Reproduced in IME mode with the Korean language.

Expected behavior: The letter should be inputted immediately

Minimal repro:

   <Grid>
        <Popup IsOpen="True" Width="100" Height="100" Placement="Center">
            <Border Background="Red">
                <TextBox Margin="5"/>
            </Border>
        </Popup>
    </Grid>

NetCore_Sample.zip Framework4_8_Sample.zip

[pchaurasia14]

@DmitryRomenskiy - This is currently under investigation. We found out that the editor that is opened is tied to OS and it may be opening on the top left corner when it doesn’t find the parent control handle.

We’ll update this thread once we confirm the behavior and its fix.

[alexdi220]

@alexdi220 - Does it still happen for .NET 6 ?

Apologize, for the misunderstanding. I really don’t mean the input delay but the placement of the IME editor - it doesn’t open near the TextBox