silverlight-3.0 - Silverlight 3 DataForm，如何显示/隐藏字段

Question

我有一个DataForm，它已设置要折叠的某些DataField的可见性，并且当用户从ComboBox选择一个选项时，应再次使某些DataField可见。

基本上(用粗略的伪代码)。

OnComboBoxChange = 
    if this.index = 1 then
        DataForm.Fields[1].Visibility = Visible
    else
        DataForm.Fields[2].Visibility = Visible

奖励积分适用于MVVM模式。

Answer 1

以下是使用MVVM避免代码隐藏的示例(值得商的MVVM，否):

<UserControl>
  <StackPanel>
    <ComboBox x:Name="comboBox" SelectionChanged="comboBox_SelectionChanged"/>
    <StackPanel Orientation="Horizontal" Visibility="{Binding IsFirstFormShown}">
      <TextBlock Text="First: "/>
      <TextBox/>
    </StackPanel>
    <StackPanel Orientation="Horizontal" Visibility="{Binding IsSecondFormShown}">
      <TextBlock Text="Second: "/>
      <TextBox/>
    </StackPanel>
  </StackPanel>
</UserControl>

然后是您的ViewModel，

public class MyFormViewModel : INotifyPropertyChanged
{
     private System.Windows.Visibility _isFirstShown;
     public System.Windows.Visibility IsFirstFormShown
     {
          get { return _isFirstShown; }
          set
          {
               _isFirstShown = value;
               if (PropertyChanged != null ) 
               { 
                    PropertyChanged(this, new PropertyChangedEventArgs(value)); 
               }
          }
     }

     //TODO: implement the other property (writing code in this edit window makes me tired)
     //hopefully you get the picture here...
}

很简单我可能会尝试为我的属性命名一些“模型”而不是“ View ”，但是这种约定并不完全不合适。