Binding and DecodePixelWidth property

本文关键字：property DecodePixelWidth and Binding | 更新日期: 2023-09-27 18:10:12

有谁知道为什么绑定不能为DecodePixelWidth属性工作吗?当我通过xml设置它时-一切正常-我看到缩放图像。当我使用绑定-图像不缩放

<Image VerticalAlignment="Top" Width="2292" Stretch="None">
    <Image.Source>
         <BitmapImage UriSource="{Binding Src}" DecodePixelWidth="{Binding DecodePixelWidth}"  />
    </Image.Source>
</Image>
    public int DecodePixelWidth
    {
        get
        {
            return _decodePixelWidth;
        }
        set
        {
            if (value != _decodePixelWidth)
            {
                _decodePixelWidth = value;
                NotifyPropertyChanged("DecodePixelWidth");
            }
        }
    }

谢谢!

Binding and DecodePixelWidth property

我有同样的问题，我已经找到了这个解决方案http://diegoparolin-codeplus.blogspot.it/2014/09/set-decodepixelheight-property-binding.html，它适用于我。

在我的MVVM WPF应用程序中，我想用存储在app.config中的值来调整位图图像的大小。因此，为了做到这一点，我尝试绑定图像。高度属性和BitmapImage。DecodePixelHeight直接到我的ViewModel，像这样:

在app.config 

<?xml version="1.0" encoding="utf-8"?>
<configuration>   
  <appSettings>   
    <add key="DocumentsToBeFiledImageHeight" value="240"/>
    <add key="DocumentsToBeFiledImageDecodePixelHeight" value="240"/>
  </appSettings> 
</configuration>

然后在我的ViewModel中我添加了这些属性

private int _documentsToBeFiledImageDecodePixelHeight;
public int DocumentsToBeFiledImageDecodePixelHeight
{
  get { return _documentsToBeFiledImageDecodePixelHeight; }
  set
  {
    if (value != _documentsToBeFiledImageDecodePixelHeight)
    {
      _documentsToBeFiledImageDecodePixelHeight = value;
      RaisePropertyChanged(DocumentsToBeFiledImageDecodePixelHeightPropertyName);
    }
  }
}
private double _documentsToBeFiledImageHeight;
public double DocumentsToBeFiledImageHeight
{
  get { return _documentsToBeFiledImageHeight; }
  set
  {
    if (value != _documentsToBeFiledImageHeight)
    {
      _documentsToBeFiledImageHeight = value;
      RaisePropertyChanged(DocumentsToBeFiledImageHeightPropertyName);
    }
  }
}

和这个代码

DocumentsToBeFiledImageHeight = Convert.ToDouble(ConfigurationManager.AppSettings["DocumentsToBeFiledImageHeight"]);

DocumentsToBeFiledImageDecodePixelHeight = Convert.ToInt32(ConfigurationManager.AppSettings["DocumentsToBeFiledImageDecodePixelHeight"]);

然后在XAML中我添加了以下代码

<Image Grid.Row="0" Height="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.DocumentsToBeFiledImageHeight, UpdateSourceTrigger=PropertyChanged}"> 
   <Image.Source>
     <BitmapImage DecodePixelHeight="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.DocumentsToBeFiledImageDecodePixelHeight, UpdateSourceTrigger=PropertyChanged}" 
        UriSource="{Binding Path=FullName}" />
   </Image.Source>
</Image>

不幸的是它不起作用，似乎DecodePixelHeight属性没有正确设置。因此，我试图直接从app.config中恢复值。我在app.config文件

的用户设置部分添加了这些参数
<userSettings>
  <Agest.AO.Client.Properties.Settings>
    <setting name="DocumentsToBeFiledImageDecodePixelHeight" serializeAs="String">
      <value>240</value>
    </setting>
    <setting name="DocumentsToBeFiledImageHeight" serializeAs="String">
      <value>240</value>
    </setting>
  </Agest.AO.Client.Properties.Settings>
</userSettings>

，我这样修改了XAML代码

xmlns:localme="clr-namespace:Agest.AO.Client.Properties" 
<Image Grid.Row="0" Height="{Binding Source={x:Static localme:Settings.Default}, Path=DocumentsToBeFiledImageHeight, Mode=OneWay}">
  <Image.Source>
    <BitmapImage DecodePixelHeight="{Binding Source={x:Static localme:Settings.Default}, Path=DocumentsToBeFiledImageDecodePixelHeight, Mode=OneWay}"
            UriSource="{Binding Path=FullName}" />
  </Image.Source>
</Image>

现在它工作了，我可以直接在配置文件中设置值。

问候!

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