如何从PictureBox中获取字节数组？

Question

我正在使用 DevExpress PictureEdit，我试图获取从以下代码加载的图像的字节

byte[] picBytes = picStudent.EditValue as byte[];

但它总是返回 null。怎么办？

Answer 1

PictureEdit.EditValue 属性根本不包含字节数组。此属性包含

System.Drawing.Image

实例 (proof)。因此，要从 PictureEdit 获取图像字节，请使用以下方法：

Image img = pictureEdit1.EditValue as Image; // or use the PictureEdit.Image property
using(MemoryStream ms = new MemoryStream()) {
    img.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
    byte[] bytes = ms.ToArray();
}

Answer 2

VB.NET 中的真实示例：

    public function Pic_to_Byte() as byte()    
       Dim img As System.Drawing.Image = TryCast(pic_Sample.EditValue, System.Drawing.Image) 
        If pic_Sample.EditValue = Nothing Then Exit Sub
        Using ms As New MemoryStream()
            img.Save(ms, System.Drawing.Imaging.ImageFormat.Png)
            Dim fileByte As Byte() = ms.ToArray()
            return fileByte
        End Using
end function