在UWP c＃中选择或点击文本框后，如何更改文本框前景的颜色？

Question

How Change color of the textbox foreground after select or tap on the textbox in UWP?

i used below code on gotfocus event of textbox.

private void tbWeight_GotFocus(object sender, RoutedEventArgs e) 
{ 
  tbWeight.Foreground = new SolidColorBrush(Colors.blue); 
}

First time when i write some thing on textbox its work fine but when textbox lost focus and then tap or get the cursor again on the same textbox the font color is get change to black. I want change black color to blue or any other color.

Answer 1

is any thing wrong

When you set Foreground property to a TextBox , this color will only be applied when the TextBox lost focus, so when you get cursor of it, this color will not be changed. This is why your code works at the first time.

Then in the LostFocus event you change the foreground to its original color. It makes your foreground changes when got focus and changes again DIRECTLY when lost focus, but the foreground color will only be applied when the TextBox lost focus, it makes your code then seems like never works.

The right way to do this work is to modify the template of TextBox , you can open the Document Outline then find your TextBox , right click it and choose Edit Template , finally select Edit a copy , the default style of your TextBox will then be generated in the Page.Resources . In this style, you can find the VisualState x:Name="Focused" , under this visual state, it controls the foreground of TextBox when it got focused, you can change it for example like this:

<VisualState x:Name="Focused">
    <Storyboard>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="PlaceholderTextContentPresenter">
            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlPlaceholderForegroundFocused}" />
        </ObjectAnimationUsingKeyFrames>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="BorderElement">
            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlBackgroundFocused}" />
        </ObjectAnimationUsingKeyFrames>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="BorderElement">
            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlBorderBrushFocused}" />
        </ObjectAnimationUsingKeyFrames>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentElement">
            <DiscreteObjectKeyFrame KeyTime="0" Value="Blue" /> <!--This one here!-->
        </ObjectAnimationUsingKeyFrames>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="RequestedTheme" Storyboard.TargetName="ContentElement">
            <DiscreteObjectKeyFrame KeyTime="0" Value="Light" />
        </ObjectAnimationUsingKeyFrames>
    </Storyboard>
</VisualState>