Question

如何更改元素VIA视图模型的样式，我想在单击按钮时切换样式。

XAML

<Grid x:Name="LayoutRoot"
      DataContext="{Binding Source={StaticResource IndexVMDataSource}}">
  <Button Content="Button"
          HorizontalAlignment="Left"
          Height="42"
          Margin="10,49,0,0"
          VerticalAlignment="Top"
          Width="130"
          Command="{Binding OnCommandName, Mode=OneWay}" />
  <HyperlinkButton Content="HyperlinkButton"
                   HorizontalAlignment="Left"
                   Height="34"
                   Margin="10,10,0,0"
                   VerticalAlignment="Top"
                   Width="216"
                   Style="{Binding QStyle}" />
</Grid>

VM

private string _styleA = "HyperLink-Navi-Container";
private string _styleB = "HyperLink-Navi-Container-2";

private string qStyle;
public string QStyle
{
     get
     {
           return qStyle;
     }
     set
     {
          if (qStyle != value)
          {
               qStyle = value;
               NotifyPropertyChanged(Utility.GetPropertyName(() => QStyle));
          }
     }
}

private ICommand onCommandName = null;
public ICommand OnCommandName
{
     get
     {
         return onCommandName;
     }
     private set
     {
         onCommandName = value;
     }
}

public void Command()
{
     if (QStyle != _styleA)
         QStyle = _styleA;
     else if (QStyle != _styleB)
         QStyle = _styleB;            
}

Answer 1

您的QStyle媒体资源必须属于Style类型：

private Style qStyle;
public Style QStyle
{
    get { return qStyle; }
    set
    {
        if (qStyle != value)
        {
             qStyle = value;
             NotifyPropertyChanged(Utility.GetPropertyName(() => QStyle));
        }
    }
}

或者你在样式绑定中使用binding converter，它为给定的字符串返回适当的Style（例如，Style资源的键）：

<HyperlinkButton ...
    Style="{Binding QStyle, Converter={StaticResource YourStringToStyleConverter}}" />

由于您尚未显示定义样式的位置，我猜它们位于您的UserControl的Resources中。然后你可以通过以下方式得到它们：

Style style = Resources["HyperLink-Navi-Container"] as Style;

如果在App.xaml中定义了资源，您可以编写

Style style = Application.Current.Resources["HyperLink-Navi-Container"] as Style;

绑定样式名称并通过VIA View Model更改样式

1 个答案: