一个实用的文件上传类and生成图片缩略图(只提供上传)

///<summary>
/// 文件上传类
///</summary>
public class UploadFile
{
///<summary>
/// 上传文件公共方法
///</summary>
///<param name="PostedFile">PostedFile</param>
///<param name="sPath">示例(格式)为：D:/Upload/</param>
///<param name="sExtension">示例(格式)为：.jpg|.gif|.bmp|.png</param>
///<param name="iSize">上传的文件不能超过的大小(单位为KB)</iSize>
///<param name="flage">是否合格</param>
///<returns></returns>
public static string UploadFileImg(HttpPostedFile PostedFile, string sPath, string sExtension, int iSize, out bool flage)
{
string fileName = null;
flage = true;

if (PostedFile != null)
{
fileName = System.IO.Path.GetFileName(PostedFile.FileName);
if (fileName != "")
{
flage = false;
//获得图片的后缀名
string imgExtension = System.IO.Path.GetExtension(fileName);
//判断是否是图片
if (sExtension.ToLower().IndexOf(imgExtension.ToLower()) == -1)
{
Csharp5K.WebLib.MessageBox.Show("只能上传格式为［" + sExtension + "］的图片文件");
}
else if (PostedFile.ContentLength / 1024 > iSize)    // 上传文件不能大于 [iSize] KB
{
Csharp5K.WebLib.MessageBox.Show("上传图片不能超过" + iSize + "KB");
}
else
{
flage = true;
fileName = Guid.NewGuid().ToString("N") + imgExtension;
//如果 sPath 中存在“:”则为物理路径
if (sPath.IndexOf(":") != -1)
PostedFile.SaveAs(sPath + fileName);
else
PostedFile.SaveAs(HttpContext.Current.Server.MapPath(sPath + fileName));
}
}
}

return fileName;
}
}

///<summary>
/// 图形操作类
///</summary>
public class Drawing
{
#region 图片处理
///<summary>
/// 生成缩略图
///</summary>
///<param name="originalImagePath">源图路径（物理路径）</param>
///<param name="thumbnailPath">缩略图路径（物理路径）</param>
///<param name="width">缩略图宽度</param>
///<param name="height">缩略图高度</param>
///<param name="mode">生成缩略图的方式【HW：指定高宽缩放（可能变形）；W：指定宽，高按比例；H：指定高，宽按比例；Cut：指定高宽裁减（不变形）】</param>
public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
{
//判断源图片是否存在，不存在就不执行
if (! File.Exists(originalImagePath)) return;

//缩略图
System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);

int towidth = width;
int toheight = height;

int x = 0;
int y = 0;
int ow = originalImage.Width;
int oh = originalImage.Height;

switch (mode.ToUpper())
{
case "HW"://指定高宽缩放（可能变形）
break;
case "W"://指定宽，高按比例
toheight = originalImage.Height * width / originalImage.Width;
break;
case "H"://指定高，宽按比例
towidth = originalImage.Width * height / originalImage.Height;
break;
case "Cut"://指定高宽裁减（不变形）
if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
{
oh = originalImage.Height;
ow = originalImage.Height * towidth / toheight;
y = 0;
x = (originalImage.Width - ow) / 2;
}
else
{
ow = originalImage.Width;
oh = originalImage.Width * height / towidth;
x = 0;
y = (originalImage.Height - oh) / 2;
}
break;
default:
break;
}

//新建一个bmp图片
System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);

//新建一个画板
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);

//设置高质量插值法
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

//设置高质量,低速度呈现平滑程度
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

//清空画布并以透明背景色填充
g.Clear(System.Drawing.Color.Transparent);

//在指定位置并且按指定大小绘制原图片的指定部分
g.DrawImage(originalImage, new System.Drawing.Rectangle(0, 0, towidth, toheight),
new System.Drawing.Rectangle(x, y, ow, oh),
System.Drawing.GraphicsUnit.Pixel);

try
{
//以jpg格式保存缩略图
bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
}
catch (System.Exception e)
{
throw e;
}
finally
{
originalImage.Dispose();
bitmap.Dispose();
g.Dispose();
}
}

///<summary>
/// 在图片上增加文字水印，好像只能是JPG格式才可能加水印呢
///</summary>
///<param name="strText">文字</param>
///<param name="sPath">原服务器图片路径</param>
///<param name="sPath_sy">生成的带文字水印的图片路径</param>
///<param name="iSize">大小</param>
public static void AddWater(string strText,string sPath, string sPath_sy,int iSize)
{
if (Path.GetExtension(sPath).ToUpper() != ".JPG") return;

System.Drawing.Image image = System.Drawing.Image.FromFile(sPath);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);
g.DrawImage(image, 0, 0, image.Width, image.Height);
System.Drawing.Font f = new System.Drawing.Font("Arial", iSize);
System.Drawing.Brush b = new System.Drawing.SolidBrush(System.Drawing.Color.Green);

g.DrawString(strText, f, b, 8, image.Height - 8 - iSize);
g.Dispose();

image.Save(sPath_sy);
image.Dispose();
}

///<summary>
/// 在图片上生成图片水印
///</summary>
///<param name="Path">原服务器图片路径</param>
///<param name="Path_syp">生成的带图片水印的图片路径</param>
///<param name="Path_sypf">水印图片路径</param>
public static void AddWaterPic(string Path, string Path_syp, string Path_sypf)
{
System.Drawing.Image image = System.Drawing.Image.FromFile(Path);
System.Drawing.Image copyImage = System.Drawing.Image.FromFile(Path_sypf);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);
g.DrawImage(copyImage, new System.Drawing.Rectangle(image.Width - copyImage.Width, image.Height - copyImage.Height, copyImage.Width, copyImage.Height), 0, 0, copyImage.Width, copyImage.Height, System.Drawing.GraphicsUnit.Pixel);
g.Dispose();

image.Save(Path_syp);
image.Dispose();
}
#endregion
}