这个属性我们平时可能并不怎么用.先来看下MSDN上的解释:
解释的非常专业,然而我并没有看懂.
说说我的理解吧:把这个属性设置为false,看起来没有变化,但操作上已经把他完全忽视了,不触发事件,可以直接点到它下面的东西.
这个属性能方便的解决工作中常见的麻烦,比如下面这个例子:
注意上面那部分.效果很简单,就是个渐变的效果.但是这个渐变贯穿了两列,就使得处理起来有点小麻烦.
当然解决方案有很多:
可以写两个ListBoxItem的样式,第一个放顶部有渐变的背景,和右部保持一致,通过样式选择器来实现.这显然比较麻烦.
还可以在大背景下放个渐变,ListBoxItem的上半部分做成透明,这样相对简单,但不一定能实现理想的效果.
IsHitTestVisible属性就很好的解决了这个问题.直接在上层放个border,背景设置成渐变,IsHitTestVisible设置为false.这样就既能看到渐变效果,又能透过border,直接点到ListBoxItem.设置一个属性就解决了问题,非常方便.相当于在上面放了个蒙板,但是这个蒙板能看到却点不到.
类似的我还想到了一个场景:
这个效果顶层是个图片,IsHitTestVisible为false,透明为0.3.
并不是图片是个背景,然后所有控件都是半透明效果.
见代码:
XMAL:
<Grid> <Grid> <Grid.RowDefinitions> <RowDefinition Height="70" /> <RowDefinition /> <RowDefinition Height="50" /> </Grid.RowDefinitions> <Border Background="Red"> <Label Content="logo" Foreground="White" /> </Border> <Grid Grid.Row="1" Background="#AAAFAF"> <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" Button.Click="StackPanel_Click"> <Button Width="132" Height="32" Margin="10" Content="金闪闪" /> <Button Width="132" Height="32" Margin="10" Content="小圆" /> </StackPanel> <Label Width="100" Height="100" Margin="76,29,266,171" Background="Green" Content="我不透明" Foreground="Blue" /> <Label Width="100" Height="40" Margin="112,40,230,220" Background="Red" Content="我不透明" Foreground="Blue" /> </Grid> <Border Grid.Row="2" Background="#555F5F"> <Label Content="状态栏" Foreground="White" /> </Border> </Grid> <Image Name="img" Width="0" Height="0" HorizontalAlignment="Center" VerticalAlignment="Center" IsHitTestVisible="False" Opacity=".8" Source="/Image/jinshanshan.png" Stretch="Fill" /> </Grid>
后台:
private void StackPanel_Click(object sender, RoutedEventArgs e) { Button btn = (Button)e.OriginalSource; string content = btn.Content.ToString(); if (content == "金闪闪") { img.Source = new BitmapImage(new Uri(@"/Image/jinshanshan.png", UriKind.Relative)); } if (content == "小圆") { img.Source = new BitmapImage(new Uri(@"/Image/jinshanshan.png", UriKind.Relative)); } DoubleAnimation daX = new DoubleAnimation(); daX.From = 0; daX.To = 400; daX.FillBehavior = FillBehavior.HoldEnd; Storyboard.SetTarget(daX, img); Storyboard.SetTargetProperty(daX, new PropertyPath(Image.WidthProperty)); DoubleAnimation daY = new DoubleAnimation(); daY.From = 0; daY.To = 400; daY.FillBehavior = FillBehavior.HoldEnd; Storyboard.SetTarget(daY, img); Storyboard.SetTargetProperty(daY, new PropertyPath(Image.HeightProperty)); DoubleAnimation daOp = new DoubleAnimation(); daOp.From = 1; daOp.To = 1; daOp.FillBehavior = FillBehavior.HoldEnd; Storyboard.SetTarget(daOp, img); Storyboard.SetTargetProperty(daOp, new PropertyPath(Image.OpacityProperty)); Storyboard sb = new Storyboard(); sb.Children.Add(daX); sb.Children.Add(daY); sb.Children.Add(daOp); sb.Begin(); }
