Question

我正在尝试创建一个以字节数组作为源的图像对象。我究竟做错了什么？

当我尝试使用字节数组作为源数据初始化图像对象时，抛出异常。我的代码中显示了异常，如下所示。

public class MyClass
{
    publuc System.Windows.Media.Imaging.BitmapImage InstanceImage { get; set; }

    public void GetImage()
    {
        // Retrieves a list of custom "Item" objects that contain byte arrays.
        // ScvClnt is our service client. The PollQueue method is designed to return information to us.
        lstQueue = SvcClnt.PollQueue(1);

        // This condition always evaluates as True, since we requested exactly 1 "Item" from the service client.
        if (lstQueue.Count == 1)
        {
            // lstQueue[0].InstanceImage is a byte array containing the data from an image file.
            // I have confirmed that it is a valid TIFF image file, by writing it to disk and opening it in MSPaint.
            if (lstQueue[0].InstanceImage != null)
            {
                // This condition is also True, since the image is just under 3KB.
                if (lstQueue[0].InstanceImage.Length > 0)
                {
                    this.InstanceImage = new System.Windows.Media.Imaging.BitmapImage();
                    this.InstanceImage.BeginInit();
                    this.InstanceImage.StreamSource = new System.IO.MemoryStream(lstQueue[0].InstanceImage);
                    InstanceImage.EndInit();
                    // The call to EndInit throws a NullReferenceException.
                    // {"Object reference not set to an instance of an object."}
                    // I have confirmed that this.InstanceImage and this.InstanceImage.StreamSource are not null at this point.
                    // They are successfully assigned in the lines of code above.
                } else InstanceImage = null;
            } else InstanceImage = null;
        } else InstanceImage = null;
    }
}

我不知道地球上可能出现什么问题任何建议都将不胜感激。

Answer 1

乍一看，我不确定我是否正在按照你的课程进行操作，但为了解决原来的问题，请试一试：

    public static Image ConvertByteArrayToImage(byte[] byteArrayIn)
    {
        MemoryStream ms = new MemoryStream(byteArrayIn);
        Image returnImage = Image.FromStream(ms);
        return returnImage;
    }

Answer 2

This MSDN forum post使用此示例作为解决方案。

using (MemoryStream stream = new MemoryStream(abyteArray0))
{
    image.Source = BitmapFrame.Create(stream, BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
}

//The field image should be of type System.Windows.Controls.Image.

我使用了BitmapFrame.Create方法，该方法仅将流作为参数，并且它像魅力一样工作。

我正在尝试创建一个以字节数组为源的图像对象。我究竟做错了什么？

2 个答案: