Silverlight MVVM中的验证模型

Question

how to validate in model in silverlight? The code sample what Im trying to achieve is shown below..

 <Grid x:Name="AddnewGrid" Margin="2" DataContext="{Binding SaveUpdateEmp, Mode=TwoWay">
        <Grid.RowDefinitions>
            <RowDefinition Height="*"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="125"></ColumnDefinition>
            <ColumnDefinition Width="10"></ColumnDefinition>
            <ColumnDefinition Width="*"></ColumnDefinition>
        </Grid.ColumnDefinitions>
        <TextBlock x:Name="EmployeeCode" Text="EmployeeCode" FontSize="14" Grid.Row="0" Grid.Column="0" VerticalAlignment="Center"></TextBlock>
        <TextBlock x:Name="EmployeeCodeSprtr" Text=":" FontSize="14" Grid.Row="0" Grid.Column="1" VerticalAlignment="Center"></TextBlock>
        <TextBox x:Name="txtEmployeeCode" Text="{Binding EmployeeCode, Mode=TwoWay, ValidatesOnDataErrors=True}" Grid.Row="0" Grid.Column="2" VerticalAlignment="Center" Width="150" HorizontalAlignment="Left"></TextBox>

        <TextBlock x:Name="EmployeeName" Text="Employee Name" FontSize="14" Grid.Row="1" Grid.Column="0" VerticalAlignment="Center"></TextBlock>
        <TextBlock x:Name="EmployeeNameSprtr" Text=":" FontSize="14" Grid.Row="1" Grid.Column="1" VerticalAlignment="Center"></TextBlock>
        <TextBox x:Name="txtEmployeeName" Text="{Binding EmployeeName, Mode=TwoWay, ValidatesOnDataErrors=True}" Grid.Row="1" Grid.Column="2" VerticalAlignment="Center" Width="150" HorizontalAlignment="Left"></TextBox>

        <TextBlock x:Name="EmployeePW" Text="PassWord" FontSize="14" Grid.Row="2" Grid.Column="0" VerticalAlignment="Center"></TextBlock>
        <TextBlock x:Name="EmployeePWSprtr" Text=":" FontSize="14" Grid.Row="2" Grid.Column="1" VerticalAlignment="Center"></TextBlock>
        <TextBox x:Name="txtEmployeePW" Text="{Binding EmployeePW, Mode=TwoWay, ValidatesOnDataErrors=True}" Grid.Row="2" Grid.Column="2" VerticalAlignment="Center" Width="150" HorizontalAlignment="Left"></TextBox>

        <TextBlock x:Name="EmployeeDesg" Text="Designation" FontSize="14" Grid.Row="3" Grid.Column="0" VerticalAlignment="Center"></TextBlock>
        <TextBlock x:Name="EmployeeDesgSprtr" Text=":" FontSize="14" Grid.Row="3" Grid.Column="1" VerticalAlignment="Center"></TextBlock>
        <TextBox x:Name="txtEmployeeDesg" Grid.Row="3" Text="{Binding EmployeeDesg, Mode=TwoWay, ValidatesOnDataErrors=True}" Grid.Column="2" VerticalAlignment="Center" Width="150" HorizontalAlignment="Left"></TextBox>

        <TextBlock x:Name="DepartmentId" Text="DepartmentID" FontSize="14" Grid.Row="4" Grid.Column="0" VerticalAlignment="Center"></TextBlock>
        <TextBlock x:Name="DepartmentIdSprtr" Text=":" FontSize="14" Grid.Row="4" Grid.Column="1" VerticalAlignment="Center"></TextBlock>
        <TextBox x:Name="txtDepartmentId" Grid.Row="4" Text="{Binding DepartmentId, Mode=TwoWay, ValidatesOnDataErrors=True}" Grid.Column="2" VerticalAlignment="Center" Width="150" HorizontalAlignment="Left"></TextBox>

        <TextBlock x:Name="DepartmentName" Text="Department" FontSize="14" Grid.Row="5" Grid.Column="0" VerticalAlignment="Center"></TextBlock>
        <TextBlock x:Name="DepartmentNameSprtr" Text=":" FontSize="14" Grid.Row="5" Grid.Column="1" VerticalAlignment="Center"></TextBlock>
        <TextBox x:Name="txtDepartmentName" Grid.Row="5" Text="{Binding DepartmentName, Mode=TwoWay, ValidatesOnDataErrors=True}" Grid.Column="2" VerticalAlignment="Center" Width="150" HorizontalAlignment="Left"></TextBox>

        <Button x:Name="CancelButton" Content="Cancel" Click="CancelButton_Click" Grid.Row="6" Grid.Column="2"  Width="75" Height="23" HorizontalAlignment="Left" />
        <Button x:Name="OKButton" Content="Save" Click="OKButton_Click" Grid.Row="6" Grid.Column="0" Width="75" Height="23" HorizontalAlignment="Left" />
    </Grid>

Here the SaveUpdateEmp is object of propertyclass in model. How to validate these fields.??

Answer 1

You need to implement INotifyDataErrorInfo on your model and make sure that you have ValidatesOnDataErrors=True on the controls/properties that you need to validate. I can give you a code sample, but I think this does a better job than I can - http://msdn.microsoft.com/en-us/library/system.componentmodel.inotifydataerrorinfo(v=vs.95).aspx . If you have questions, I'm happy to answer.