如何在WP8中使用C＃在网格中显示图像？

Question

我需要在WP8中插入图像。 我有一堆图像。 单击图像后，必须将其设置为网格的背景。 所以我创建了一个空的“ grid1”和按钮。 在按钮单击事件中编写了以下代码，但未显示图像！

 private void bg6_Click(object sender, RoutedEventArgs e)
    {
        System.Windows.Media.ImageBrush myBrush = new System.Windows.Media.ImageBrush();
        Image image = new Image();
        image.Source = new System.Windows.Media.Imaging.BitmapImage(
            new Uri("\\PhoneApp2\\PhoneApp2\\Assets\\bg\\bg5.jpg"));
        myBrush.ImageSource = image.Source;
       // Grid grid1 = new Grid();
        grid1.Background = myBrush;          
    }

Answer 1

很难知道图像文件是否位于正确的位置并设置为正确的构建类型。 我建议将事件处理程序添加到Image failed事件 。

private void bg6_Click(object sender, RoutedEventArgs e)
{
  System.Windows.Media.ImageBrush myBrush = new System.Windows.Media.ImageBrush();
  Image image = new Image();
  image.ImageFailed += (s, e) => MessageBox.Show("Failed to load: " + e.ErrorException.Message);
  image.Source = new System.Windows.Media.Imaging.BitmapImage(
  new Uri("\\PhoneApp2\\PhoneApp2\\Assets\\bg\\bg5.jpg"));
  myBrush.ImageSource = image.Source;
  // Grid grid1 = new Grid();
  grid1.Background = myBrush;          
}

Answer 2

首先，您不需要使用Image来填充URI的背景。

private void bg6_Click(object sender, RoutedEventArgs e)
{
    System.Windows.Media.ImageBrush myBrush = new System.Windows.Media.ImageBrush(new Uri("\\PhoneApp2\\PhoneApp2\\Assets\\bg\\bg5.jpg"));
   // Grid grid1 = new Grid();
    grid1.Background = myBrush;          
}

其次，最好使用XAML设计它，并通过创建具有可见性和source属性的helper类来从代码中操纵可见性和源代码。 不要忘记在该类中实现INotifyPropertyChanged接口。

<Grid x:Name="myGrid" DataContext="{Binding}" Visibility="{Binding Path=VisibleProperty}">
<Grid.Background>
<ImageBrush x:Name="myBrush" ImageSource="{Binding Path=SourceProperty}"></ImageBrush>
</Grid.Background>

并在代码中：

private void bg6_Click(object sender, RoutedEventArgs e)
{
   myGrid.DataContext=new myImagePresenterClass(new Uri("\\PhoneApp2\\PhoneApp2\\Assets\\bg\\bg5.jpg"), Visibility.Visible)
}

public class myImagePresenterClass:INotifyPropertyChanged
{
private URI sourceProperty
Public URI SourceProperty
{
get
 {
  return sourceProperty;
 }
set
 {
   sourceProperty=value;
   if(PropertyChanged!=null){PropertyChanged(this, new PropertyChangedEventArgs("SourceProperty"));}
 }
}

//Don't forget to implement the Visible property the same way as SourceProperty and the class constructor.
}

Answer 3

我发现了错误...对不起。 我没有正确遵循语法。 我错过了Uri方法中的“ @”。 代表这一点的正确方法是

 private void bg1_Click(object sender, RoutedEventArgs e)
    {
        System.Windows.Media.ImageBrush myBrush = new System.Windows.Media.ImageBrush();
        Image image = new Image();
        image.ImageFailed += (s, i) => MessageBox.Show("Failed to load: " + i.ErrorException.Message);
        image.Source = new System.Windows.Media.Imaging.BitmapImage(new Uri(@"/Assets/bg/bg1.jpg/", UriKind.RelativeOrAbsolute));
        myBrush.ImageSource = image.Source;
        grid1.Background = myBrush;

    }