將databound datagridview圖像保存到memoryStream

Question

關於如何將圖像從數據綁定的datagidview控件保存到memoryStream的任何示例？

我知道用圖片框，我們可以做

pictureBox1.Image.Save(ms, ImageFormat.Jpeg); 

什麼數據綁定DataGridViewImage？

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我收到錯誤「對象引用不設置到對象的實例」

Private Sub conv_photo() 

    'converting photo to binary data 


    Dim ms As MemoryStream = New MemoryStream() 
    TryCast(DataGridView1.Columns(1), DataGridViewImageColumn).Image.Save(ms, ImageFormat.Jpeg)`Right here error` 

    Dim photo_aray As Byte() = New Byte(CInt(ms.Length - 1)) {} 
    ms.Position = 0 
    ms.Read(photo_aray, 0, photo_aray.Length) 
    _Command.Parameters.AddWithValue("@_m_barrImg", photo_aray) 

End Sub 

Answer 1

你會做同樣的事情用一個DataGridViewImageColumn，你只需要得到一個參考該欄例如

(dataGrid.Columns[columnIndex] as DataGridViewImageColumn).Image.Save(ms, ImageFormat.Jpeg);