c# - TimePicker(AvalonControlsLibrary)如何绑定(bind)校验？

Question

我想将自定义验证绑定(bind)到 TimePicker 自定义控件，但下面的代码显示“无法将内容添加到 TimePicker 的对象类型。”。

<Controls:TimePicker Name="TimePickerEndTime"
                      Grid.Row="2"
                      Grid.Column="1"
                      SelectedHour="11" 
                      SelectedMinute="20" 
                      SelectedSecond="0"
                         >
        <Binding Path="EndTime" UpdateSourceTrigger="PropertyChanged">
            <Binding.ValidationRules>
                <Validators:MyCustomTimepickerValidation ErrorMessage="{DynamicResource NumberValidatorMesage}"/>
            </Binding.ValidationRules>
        </Binding>
    </Controls:TimePicker>

Answer 1

你应该把 Binding 放在 SelectedTime 标签中:

<Controls:TimePicker Name="TimePickerEndTime"
                  Grid.Row="2"
                  Grid.Column="1"
                  SelectedHour="11" 
                  SelectedMinute="20" 
                  SelectedSecond="0"
                     >
     <Controls:TimePicker.SelectedTime>
        <Binding Path="EndTime" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged">
            <Binding.ValidationRules>
                <Validators:MyCustomTimepickerValidation ErrorMessage="{DynamicResource NumberValidatorMesage}"/>
            </Binding.ValidationRules>
        </Binding>
     </Controls:TimePicker.SelectedTime>
</Controls:TimePicker>

完整教程如何为 TimePicker 创建 ValidationRules。

1) 创建样式来显示错误信息:

<Style x:Key="timePickerInError" TargetType="{x:Type Controls:TimePicker}">
    <Style.Triggers>
        <Trigger Property="Validation.HasError" Value="true">
            <Setter Property="ToolTip"
                  Value="{Binding RelativeSource={x:Static RelativeSource.Self},
                      Path=(Validation.Errors)[0].ErrorContent}"/>
            <Setter Property="Background" Value="Red" />
        </Trigger>
    </Style.Triggers>
</Style>

2) 创建继承自 ValidationRule 的自定义类:

public class TimeRangeRule : ValidationRule
{
    private TimeSpan _min;
    private TimeSpan _max;

    public TimeRangeRule()
    {          
    }

    public TimeSpan Min
    {
        get { return _min; }
        set { _min = value; }
    }

    public TimeSpan Max
    {
        get { return _max; }
        set { _max = value; }
    }

    public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo)
    {
        if (value != null)
        {
            TimeSpan time = (TimeSpan)value;

            if ((time < Min) || (time > Max))
            {
                return new ValidationResult(false,
                  "Please enter the time in the range: " + Min + " - " + Max + ".");
            }
            else
            {
                return new ValidationResult(true, null);
            }
        }
        else
            return new ValidationResult(true, null);
    }
}

3) 使用 Style 和 ValidationRules 编写适当的绑定(bind):

<Controls:TimePicker Name="TimePickerEndTime"                               
          Style="{StaticResource timePickerInError}" >
    <Controls:TimePicker.SelectedTime>
        <Binding Path="EndTime" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged" >
            <Binding.ValidationRules>
                <Validators:TimeRangeRule Min="10:00:00" Max="15:00:00"/>
            </Binding.ValidationRules>
        </Binding>
    </Controls:TimePicker.SelectedTime>
</Controls:TimePicker>