wpf ValicationRule 和 BindingGroup

原文: wpf ValicationRule 和 BindingGroup

1.自定义一个ValicationRule：

 public class RangeValidationRule:ValidationRule
    {
        public override ValidationResult Validate(object value, CultureInfo cultureInfo)
        {
            double myValue = 0;
            if(double.TryParse(value.ToString(),out myValue))
            {
                if (myValue >= 0 && myValue <= 100)
                {
                    return new ValidationResult(true, null);
                }
            }
            return new ValidationResult(false, "Input should between 0 and 100");
        }
    }

使用：

 <Grid>
        <Slider Margin="10,120,-10,-120" Minimum="0" Maximum="100" Name="slider" Value="10"></Slider>
        <TextBox Height="50" Margin="5,30,5,240" >
            <TextBox.Text>
                <Binding ElementName="slider" Path="Value" UpdateSourceTrigger="PropertyChanged">
                    <Binding.ValidationRules>
                        <local:RangeValidationRule/>
                    </Binding.ValidationRules>
                </Binding>
            </TextBox.Text>
        </TextBox>
      
    </Grid>

2.BindingGroup的使用

 public class MyClass 
    {             
        public int StartValue { get; set; }    
        public int EndValue { get; set; } 
    }

 public class RangeValidationRule : ValidationRule
    {
        public override ValidationResult Validate(object value, CultureInfo cultureInfo)
        {
            BindingGroup bindingGroup = (BindingGroup)value;
            MyClass mc = (MyClass)bindingGroup.Items[0];
            int startValue = (int)bindingGroup.GetValue(mc, "StartValue");
            int endValue = (int)bindingGroup.GetValue(mc, "EndValue");
            bool isEnabled = (bool)bindingGroup.GetValue(mc, "IsEnabled");

            if (startValue > endValue)
            {
                return new ValidationResult(true, null);
            }

            return new ValidationResult(false, "Input should between 0 and 100");
        }
    }

 MyClass mc = new MyClass();
        public MainWindow()
        {
            InitializeComponent();
         
            this.DataContext = mc;
        }

 <Grid Name="Grid1" Width="400" Height="300" >
       
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <Grid.BindingGroup>
            <BindingGroup NotifyOnValidationError="True">
                <BindingGroup.ValidationRules >
                    <local:RangeValidationRule2 ValidationStep="ConvertedProposedValue"  />
                </BindingGroup.ValidationRules>
            </BindingGroup>
        </Grid.BindingGroup>
        <TextBox Grid.Row="0" Name="tb1" Text="{Binding StartValue}">
           
        </TextBox>
        <TextBox Grid.Row="1" Text="{Binding EndValue}"/>
        <Button Name="btn1" Content="btn1" Grid.Row="2" Click="Button_Click"  >
          
           
        </Button>
    </Grid>

验证：

  this.Grid1.BindingGroup.CommitEdit();