WPF TextBox 在验证上设置红色边框
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WPF TextBox setting red border on Validation
提问by Piotr Lazarczyk
I'm trying to make textbox's border red when it's empty. Here's my xaml:
我试图在文本框为空时将其边框设为红色。这是我的 xaml：
<TextBox Style="{StaticResource TextBoxEmptyError}" Name="tbFilename" Grid.Column="1" >
<Binding Path="Text" UpdateSourceTrigger="PropertyChanged" NotifyOnValidationError="True">
<Binding.ValidationRules>
<local:EmptyRule />
</Binding.ValidationRules>
</Binding>
</TextBox>
style i'm trying to set:
我正在尝试设置的样式：
<Style x:Key="TextBoxEmptyError" TargetType="{x:Type TextBox}">
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="True">
<Setter Property="BorderThickness" Value="2" />
<Setter Property="BorderBrush" Value="Red" />
</Trigger>
</Style.Triggers>
</Style>
EmptyRule:
空规则：
public class EmptyRule : ValidationRule
{
public override ValidationResult Validate(object value, CultureInfo cultureInfo)
{
if (string.IsNullOrEmpty(value as string))
return new ValidationResult(false, null);
else
return new ValidationResult(true, null);
}
}
In debugger it looks like Validation method isn't used at all. What am I doing wrong?
在调试器中，看起来根本没有使用 Validation 方法。我究竟做错了什么？
采纳答案by StepUp
I cannot see where you set DataContextbetween XAML and viewModel.
我看不到您DataContext在 XAML 和 viewModel 之间设置的位置。
DataContextis a way to know where XAML(View, your Window) can get data from.
DataContext是一种了解 XAML(View, your Window) 可以从何处获取数据的方法。
For example, you have model class:
例如，您有模型类：
internal class SomeUser
{
private string _name;
private string _address;
public string Name
{
get { return _name; }
set
{
_name = value;
}
}
public string Address
{
get { return _address; }
set { _address = value; }
}
}
Then you should set DataContextto your Window. For example, in code-behind:
然后你应该设置DataContext为你的Window. 例如，在代码隐藏中：
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
DataContext = new SomeUser();
}
}
then XAML should looks like this:
那么 XAML 应该是这样的：
<Grid>
<Grid.Resources>
<Style x:Key="CustomTextBoxTextStyle" TargetType="TextBox">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type TextBox}">
<Border x:Name="bg" BorderBrush="#FF825E5E" BorderThickness="1">
<ScrollViewer x:Name="PART_ContentHost" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="Validation.HasError" Value="True">
<Trigger.Setters>
<Setter Property="ToolTip" Value="{Binding RelativeSource={RelativeSource Self},Path=(Validation.Errors)[0].ErrorContent}"/>
<Setter Property="BorderThickness" TargetName="bg" Value="2"/>
<Setter Property="BorderBrush" TargetName="bg" Value="Red"/>
</Trigger.Setters>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Grid.Resources>
</Grid>
<TextBox Style="{StaticResource CustomTextBoxTextStyle}" Height="23" Name="textBox1" Margin="25">
<Validation.ErrorTemplate>
<ControlTemplate>
<DockPanel>
<TextBlock Foreground="Red" DockPanel.Dock="Right">!</TextBlock>
<AdornedElementPlaceholder x:Name="ErrorAdorner"
></AdornedElementPlaceholder>
</DockPanel>
</ControlTemplate>
</Validation.ErrorTemplate>
<TextBox.Text>
<Binding Path="Name" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged">
<Binding.ValidationRules>
<local:NameValidator></local:NameValidator>
</Binding.ValidationRules>
</Binding>
</TextBox.Text>
</TextBox>
回答by Jan Paolo Go
your Bindingto Textshould be like this...
你Binding的Text应该是这样的...
<Binding Path="Text" UpdateSourceTrigger="LostFocus" Mode="OneWayToSource" NotifyOnValidationError="True" RelativeSource="{RelativeSource Self}">
