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这是我当前的拖放代码，我正在从电子邮件（不是附件）中拖动图像，光标变化很好，但是当它被删除时出错

Unable to cast object of type 'System.IO.MemoryStream' to type 'System.Drawing.Imaging.Metafile[]'.

我究竟做错了什么？MetafilePict 是否使用了错误的数据格式？

Private Sub ImageViewer_DragDrop(ByVal sender As System.Object, _
                                 ByVal e As System.Windows.Forms.DragEventArgs) _
                             Handles MyBase.DragDrop

    If (e.Data.GetDataPresent(DataFormats.MetafilePict, False)) Then
        Try
            For Each path As Metafile In CType(e.Data.GetData(DataFormats.MetafilePict), Metafile())
                'Do stuff with data
            Next
        Catch ex As Exception
            MessageBox.Show("Error Doing Drag/Drop")
        End Try
    End If
End Sub

Private Sub ImageViewer_DragEnter(ByVal sender As System.Object, ByVal _
                                  e As System.Windows.Forms.DragEventArgs) _
                              Handles MyBase.DragEnter
    If (e.Data.GetDataPresent(DataFormats.MetafilePict, True)) Then
        e.Effect = DragDropEffects.Copy
    End If
End Sub
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1 回答 1

0

好的回答我自己的问题。经过大量的探索后，我发现这适用于将图像从 Outlook 拖动到 vb.net。由于您无法从 Outlook 中拖动多个图像，因此我可以摆脱 For Each 循环。

代替： 

If (e.Data.GetDataPresent(DataFormats.MetafilePict, False)) Then
    Try
        For Each path As Metafile In CType(e.Data.GetData(DataFormats.MetafilePict), Metafile())
            'Do stuff with data
        Next

和：

If (e.Data.GetDataPresent(DataFormats.MetafilePict, False)) Then
        Try
            Dim img As Image = DirectCast(e.Data.GetData(DataFormats.Bitmap, True), Image)
            'Do stuff with data
于 2013-05-23T20:40:57.607 回答