我没有遇到绑定错误,这段代码在其他地方可以运行。我还没有找出我现在做了什么不同于它可以正常工作的代码,而且代码量也不是很大。
在UserControl.Resource:
<Style TargetType="TextBox">
<Setter Property="BorderBrush" Value="DarkBlue"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="Margin" Value="0,1,0,1"/>
<Setter Property="Validation.ErrorTemplate">
<Setter.Value>
<ControlTemplate>
<StackPanel Orientation="Horizontal">
<AdornedElementPlaceholder/>
<Grid Margin="2,0,0,0">
<Ellipse Width="20" Height="20" Fill="Red"/>
<TextBlock Foreground="White" Text="X" FontWeight="Bold"
HorizontalAlignment="Center" VerticalAlignment="Center"/>
</Grid>
</StackPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="True">
<Setter Property="ToolTip"
Value="{Binding RelativeSource={RelativeSource Self},
Path=(Validation.Errors)[0].ErrorContent}"/>
</Trigger>
</Style.Triggers>
</Style>
下面也有Xaml代码:
<TextBlock Height="23" HorizontalAlignment="Left" Margin="22,90,0,0"
Text="Keywords" VerticalAlignment="Top"/>
<TextBox Height="23" HorizontalAlignment="Left" Margin="22,108,0,0"
VerticalAlignment="Top" Width="244">
<Binding Path="Tags" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged">
<Binding.ValidationRules>
<DataErrorValidationRule ValidatesOnTargetUpdated="False"/>
</Binding.ValidationRules>
</Binding>
</TextBox>
当用户输入的Model.Tags
属性长度超过10个字符时,我的ViewModel中的保存按钮才会被激活。当我输入10、11个字符然后又删除至8个字符时,按钮的激活/禁用功能正常工作。所有属性更改都已触发。
模型:
namespace TBM.Model
{
public class Document : EntityBase , IDataErrorInfo
{
public int Id { get; set; }
public string DocumentName { get; set; }
public string Tags { get; set; }
public byte[] DocumentData { get; set; }
public int PeriodId { get; set; }
string IDataErrorInfo.Error { get { return null; } }
string IDataErrorInfo.this[string propertyName]
{
get { return this.GetValidationError(propertyName); }
}
public bool IsValid
{
get
{
foreach (string property in ValidatedProperties)
if (GetValidationError(property) != null)
return false;
return true;
}
}
static readonly string[] ValidatedProperties = { "Tags", };
private string GetValidationError(string propertyName)
{
if (Array.IndexOf(ValidatedProperties, propertyName) < 0)
return null;
string error = null;
switch (propertyName)
{
case "Tags": error = this.IsTagsEmpty(Tags); break;
default:
Debug.Fail("Unexpected property being validated on Document: " + propertyName);
break;
}
return error;
}
private string IsTagsEmpty(string value)
{
if (value != null && value.Trim().Length >= 10)
return null;
else
return "The keywords must have at least 10 chars!";
}
}
}
ViewModel:
public RelayCommand SaveDocumentCommand
{
get { return _saveDocumentCommand ?? (_saveDocumentCommand =
new RelayCommand(() => SaveDocument(),() => CanSaveDocument())); }
}
private bool CanSaveDocument()
{
return _document.IsValid;
}
//...
错误模板中的红色椭圆不显示,这是不起作用的。
更新: 在测试项目中确切的下面代码可以工作。但在我的生产项目中找不到资源?为什么会这样?
<TextBlock Height="23" HorizontalAlignment="Left" Margin="22,89,0,0"
Text="Keywords" VerticalAlignment="Top"/>
<TextBox Style="{StaticResource bla}" Height="23" HorizontalAlignment="Left"
Margin="22,109,0,0" VerticalAlignment="Top" Width="244">
<Binding Path="Tags" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged">
<Binding.ValidationRules>
<DataErrorValidationRule ValidatesOnTargetUpdated="False"
ValidationStep="UpdatedValue"/>
</Binding.ValidationRules>
</Binding>
</TextBox>
<UserControl.Resources>
<Style x:Name="bla" TargetType="TextBox">
<Setter Property="BorderBrush" Value="DarkBlue"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="Margin" Value="0,1,0,1"/>
<Setter Property="Validation.ErrorTemplate">
<Setter.Value>
<ControlTemplate>
<StackPanel Orientation="Horizontal">
<AdornedElementPlaceholder/>
<Grid Margin="2,0,0,0">
<Ellipse Width="20" Height="20" Fill="Red"/>
<TextBlock Foreground="White" Text="X" FontWeight="Bold"
HorizontalAlignment="Center" VerticalAlignment="Center"/>
</Grid>
</StackPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="True">
<Setter Property="ToolTip"
Value="{Binding RelativeSource={RelativeSource Self},
Path=(Validation.Errors)[0].ErrorContent}"/>
</Trigger>
</Style.Triggers>
</Style>
</UserControl.Resources>