由网友(yī個亽旳褙影)分享简介：我想随便挑使用文件：专用异步无效Button_Click_1（对象发件人，RoutedEventArgs E）{尝试{FileOpenPicker openPicker =新FileOpenPicker（）;openPicker.ViewMode = PickerViewMode.Thumbnail;openPick...

我想随便挑使用文件：

 专用异步无效Button_Click_1（对象发件人，RoutedEventArgs E）
{
    尝试
    {
            FileOpenPicker openPicker =新FileOpenPicker（）;
            openPicker.ViewMode = PickerViewMode.Thumbnail;
            openPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
            openPicker.FileTypeFilter.Add（JPG）;
            openPicker.FileTypeFilter.Add（JPEG）;
            openPicker.FileTypeFilter.Add（。PNG）;

            StorageFile文件=等待openPicker.PickSingleFileAsync（）;
            如果（文件！= NULL）
            {
                //应用程序现在已经读/写访问拿起文件
                txt.Text =捡到的文件：+ file.Name;
            }
            其他
            {
                txt.Text =操作被取消。
            }

    }
    赶上（例外的例外）
    {
        txt.Text = exception.Message;
    }
}
 

...但它抛出一个异常：'不支持指定的方法;

我复制并从Windows Phone 8的文档粘贴在code。没有他们的样品的工作。我想，也许我缺少一个文件的能力/合同或什么，但他们甚至没有在VS中存在手机的应用程序。

为什么不工作的呢？

我已经跟踪它的尝试的第一行：

  FileOpenPicker openPicker =新FileOpenPicker（）; //这是抛出异常就行了。
 

解决方案

据的MSDN，论坛，从我承担的答案是MS的员工（here):

  

我们目前不支持选择的文件以外的其他照片或   从其他商店的应用程序选择文件。

所以看起来你被卡住了 PhotoChooserTask 而不是 FileOpenPicker 。

I am trying to just pick a file using:

private async void Button_Click_1(object sender, RoutedEventArgs e)
{
    try
    {
            FileOpenPicker openPicker = new FileOpenPicker();
            openPicker.ViewMode = PickerViewMode.Thumbnail;
            openPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
            openPicker.FileTypeFilter.Add(".jpg");
            openPicker.FileTypeFilter.Add(".jpeg");
            openPicker.FileTypeFilter.Add(".png");

            StorageFile file = await openPicker.PickSingleFileAsync();
            if (file != null)
            {
                // Application now has read/write access to the picked file
                txt.Text = "Picked file: " + file.Name;
            }
            else
            {
                txt.Text = "Operation cancelled.";
            }

    }
    catch (Exception exception)
    {
        txt.Text = exception.Message;
    }
}

...but It throws an exception: `Specified method is not supported.";

I copied and pasted the code from the Windows Phone 8 docs. None of their samples work. I thought that maybe I am missing a Documents capability/Contract or whatever but they don't even exist in VS for Phone apps.

Why won't this work?

I have tracked it down to the very first line of the try:

FileOpenPicker openPicker = new FileOpenPicker(); // this is the line the exception is thrown on.

解决方案

According to the MSDN-forums and an answer from what i assume is a MS employee (here):

We do not currently support choosing files other than photos or choosing files from other Store apps.

So it looks like you are stuck with the PhotoChooserTask instead of FileOpenPicker.