我在客户端使用了plupload来上传图像。然后在我的控制器中有以下逻辑:
public ActionResult UploadFile()
{
try
{
var file = Request.Files.Count > 0 ? Request.Files[0] : null;
using (var fileStream = new MemoryStream())
{
using (var oldImage = new Bitmap(file.InputStream))
{
var format = oldImage.RawFormat;
using (var newImage = ImageUtility.ResizeImage(oldImage, 800, 2000))
{
newImage.Save(fileStream, format);
}
byte[] bits = fileStream.ToArray();
}
}
{
catch (Exception ex)
{
}
}
ImageUtility.ResizeImage方法:
public static class ImageUtility
{
public static Bitmap ResizeImage(Bitmap image, int width, int height)
{
if (image.Width <= width && image.Height <= height)
{
return image;
}
int newWidth;
int newHeight;
if (image.Width > image.Height)
{
newWidth = width;
newHeight = (int)(image.Height * ((float)width / image.Width));
}
else
{
newHeight = height;
newWidth = (int)(image.Width * ((float)height / image.Height));
}
var newImage = new Bitmap(newWidth, newHeight);
using (var graphics = Graphics.FromImage(newImage))
{
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
graphics.FillRectangle(Brushes.Transparent, 0, 0, newWidth, newHeight);
graphics.DrawImage(image, 0, 0, newWidth, newHeight);
return newImage;
}
}
}
我这里遇到的问题是,图片大小增加了。 我上传的图片大小为1.62MB,在调用控制器后,它创建了Bitmap实例,然后将Bitmap保存到文件流,并使用“fileStream.ToArray();”读取位,结果我在“bits”中获得了2.35MB。
请问有人能告诉我将图片保存为位图后大小增加的原因。我需要Bitmap,因为我需要检查上传的图像的宽度和高度,如果需要,就进行调整。