求对缩小图片尺寸代码

[豆丁_]

怎么说呢，举例：将一张分辨率大于800X600的图缩小到800X600的格式，尺寸是可控的，但是只是缩小，并且不更改原来的图片，找到了一个GetThumbnailImage（）的方法，但是处理出来的图片非常的模糊

[hflkl1314]

没啥 本来就有的代码
大家共享嘛

[豆丁_]

自己up

[qq283617300]

没研究过~~帮你顶下

[hflkl1314]

/// <summary>
/// 将一张指定图片另存为一张指定尺寸的图片
/// </summary>
/// <param name="oldfile">原图</param>
/// <param name="newfile">新图</param>
/// <param name="width">新图宽</param>
/// <param name="height">新图高</param>
/// <returns></returns>
public bool Compress(Stream oldfile, string newfile, int width, int height)
{
try
{
System.Drawing.Image img = System.Drawing.Image.FromStream(oldfile);
System.Drawing.Imaging.ImageFormat thisFormat = img.RawFormat;
Size newSize = new Size(width, height);
Bitmap outBmp = new Bitmap(newSize.Width, newSize.Height);
Graphics g = Graphics.FromImage(outBmp);
g.CompositingQuality = CompositingQuality.HighQuality;
g.SmoothingMode = SmoothingMode.HighQuality;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(img, new Rectangle(0, 0, newSize.Width, newSize.Height), 0, 0, img.Width, img.Height, GraphicsUnit.Pixel);
g.Dispose();
EncoderParameters encoderParams = new EncoderParameters();
long[] quality = new long[1];
quality[0] = 100;
EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
encoderParams.Param[0] = encoderParam;
ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();
ImageCodecInfo jpegICI = null;
for (int x = 0; x < arrayICI.Length; x++)
if (arrayICI[x].FormatDescription.Equals("JPEG"))
{
jpegICI = arrayICI[x];//设置JPEG编码
break;
}
img.Dispose();
if (jpegICI != null)
outBmp.Save(newfile, System.Drawing.Imaging.ImageFormat.Jpeg);
else
outBmp.Save(newfile, System.Drawing.Imaging.ImageFormat.Jpeg);
outBmp.Dispose();
return true;
}
catch
{
return false;
}
}

[aimeast]

用缩略图。
在此查看样例：
http://msdn.microsoft.com/zh-cn/library/system.drawing.image.getthumbnailimage(VS.80).aspx

[豆丁_]

谢谢3楼的，OK了