基于文本的长度WPF文本框背景颜色

问题描述：

我在ListView的ItemTemplate一个文本框。我想文本框的背景颜色变为红色每当长度大于75个字符，我需要的背景色，以更新的用户类型。什么是WPF实现这一目标的最佳途径？

I have a textbox in a listview itemtemplate. I want to change the background color of the textbox to red whenever the length is greater than 75 characters, and I need the background color to update as the user types. What is the best way to achieve this in WPF?

答

我相信这样的事情会工作。它会要求你写你自己的背景颜色的转换器。

I believe something like this would work. It would require you to write your own background color converter.

<TextBox 
    Background="{Binding RelativeSource={RelativeSource self},
        Path=Text, 
        UpdateSourceTrigger=PropertyChanged,
        Converter={StaticResource backgroundColorConverter}}" 
    ... 
/>

另一种选择是使用一个DataTrigger像的下方。这还需要一个转换器，以检查是否字符串的长度超过75

Another option would be to use a DataTrigger like below. This would also require a converter to check if the length of the string was more than 75.

<TextBox>
    ....
    <TextBox.Style>
        <Style TargetType="{x:Type TextBox}">
            <Setter Property="Background" Value="YourDefaultColor" />
            <Style.Triggers>
                <DataTrigger Binding="{Binding ElementName=YourTextBox, Path=Text, Converter={StaticResource textLengthColorConverter}}" Value="True">
                    <Setter Property="Background" Value="Red" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </TextBox.Style>
</TextBox>

基于文本的长度WPF文本框背景颜色

相关推荐