1

我从链接文本中获取了这段代码并对其进行了一些修改，因为我想将它与我的 AJAX 上传器一起使用，该上传器需要一个流用于将上传的项目添加到附件显示中；

public Stream ResizeFromStream(int MaxSideSize, Stream Buffer)
{
    int intNewWidth;
    int intNewHeight;
    System.Drawing.Image imgInput = System.Drawing.Image.FromStream(Buffer);

    // GET IMAGE FORMAT
    ImageFormat fmtImageFormat = imgInput.RawFormat;

    // GET ORIGINAL WIDTH AND HEIGHT
    int intOldWidth = imgInput.Width;
    int intOldHeight = imgInput.Height;

    // IS LANDSCAPE OR PORTRAIT ?? 
    int intMaxSide;

    if (intOldWidth >= intOldHeight)
    {
        intMaxSide = intOldWidth;
    }
    else
    {
        intMaxSide = intOldHeight;
    }


    if (intMaxSide > MaxSideSize)
    {
        // SET NEW WIDTH AND HEIGHT
        double dblCoef = MaxSideSize / (double)intMaxSide;
        intNewWidth = Convert.ToInt32(dblCoef * intOldWidth);
        intNewHeight = Convert.ToInt32(dblCoef * intOldHeight);
    }
    else
    {
        intNewWidth = intOldWidth;
        intNewHeight = intOldHeight;
    }

    // CREATE NEW BITMAP
    Bitmap bmpResized = new Bitmap(imgInput, intNewWidth, intNewHeight);

    // SAVE BITMAP TO STREAM
    MemoryStream imgStream = new MemoryStream();
    bmpResized.Save(imgStream, imgInput.RawFormat);

    // RELEASE RESOURCES
    imgInput.Dispose();
    bmpResized.Dispose();
    Buffer.Close();

    return imgStream;
}

并在这段代码中被调用；

private void ItemPicture_FileUploaded(object sender, UploaderEventArgs args)
{
    if (GetVisibleItemCount() >= 5)
        return;

    using (System.IO.Stream stream = args.OpenStream())
    {
        ImageResize ir = new ImageResize();
        // This returns a 0 byte stream
        ItemPictureAttachments.Upload(args.FileSize, args.FileName, ir.ResizeFromStream(640, stream));
        // This works fine
        // ItemPictureAttachments.Items.Add(args.FileSize, args.FileName, stream);
    }
}

在将流返回到调用它的位置时我做错了吗？谢谢！

4

2 回答 2

0

我使用常规 ASP.NET 文件控件的 PostedFile.Inputstream 属性测试了您的 ResizeFromStream 方法，并且效果很好。也许问题出在您用来检索文件流的组件 (args.OpenStream()) 上？

于 2009-08-20T10:53:12.643 回答
0

根据您的代码，一切看起来都不错。我建议你在

Bitmap bmpResized = new Bitmap(imgInput, intNewWidth, intNewHeight);

并检查 imgInput 是否不为空。或者 ImageRawFormat 可能有问题。

于 2009-08-20T07:42:49.157 回答