Asp.net(C#)给图片加上水印效果
private void Btn_Upload_Click(object sender, System.EventArgs e)
{
if(UploadFile.PostedFile.FileName.Trim()!="")
{
//上传文件
string extension = Path.GetExtension(UploadFile.PostedFile.FileName).ToUpper();
string fileName = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + DateTime.Now.Day.ToString() + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString();
string path = Server.MapPath(".") + "/UploadFile/" + fileName + extension;
UploadFile.PostedFile.SaveAs(path);
//加文字水印，注意，这里的代码和以下加图片水印的代码不能共存
System.Drawing.Image image = System.Drawing.Image.FromFile(path);
Graphics g = Graphics.FromImage(image);
g.DrawImage(image, 0, 0, image.Width, image.Height);
Font f = new Font("Verdana", 32);
Brush b = new SolidBrush(Color.White);
string addText = AddText.Value.Trim();
g.DrawString(addText, f, b, 10, 10);
g.Dispose();
//加图片水印
System.Drawing.Image image = System.Drawing.Image.FromFile(path);
System.Drawing.Image copyImage = System.Drawing.Image.FromFile( Server.MapPath(".") + "/Alex.gif");
Graphics g = Graphics.FromImage(image);
g.DrawImage(copyImage, new Rectangle(image.Width-copyImage.Width, image.Height-copyImage.Height, copyImage.Width, copyImage.Height), 0, 0, copyImage.Width, copyImage.Height, GraphicsUnit.Pixel);
g.Dispose();
//保存加水印过后的图片,删除原始图片
string newPath = Server.MapPath(".") + "/UploadFile/" + fileName + "_new" + extension;
image.Save(newPath);
image.Dispose();
if(File.Exists(path))
{
File.Delete(path);
}
Response.Redirect(newPath);
}
}
//生成缩略图#region //生成缩略图
/**//// <summary>
/// 生成缩略图
/// </summary>
/// <param name="str_originalImagePath">源图路径（物理路径）</param>
/// <param name="str_ThumbnailPath">缩略图路径（物理路径）</param>
/// <param name="i_width">缩略图宽度</param>
/// <param name="i_height">缩略图高度</param>
/// <param name="str_mode">生成缩略图的模式</param>
public static void MakeThumbnail(string str_originalImagePath,string str_ThumbnailPath,int i_width,int i_height,string str_mode)
{
System.Drawing.Image img_OriginalImage = Image.FromFile(str_originalImagePath);
int i_ToWidth = i_width;
int i_ToHeight = i_height;
int x = 0;
int y = 0;
int i_OriginalWidth = img_OriginalImage.Width;
int i_OriginalHeight = img_OriginalImage.Height;
switch(str_mode)
{
case "HW": //按照指定的高度和宽度进行缩放（可能变形）
break;
case "W" : //指定宽度，高度按照比例缩放
i_ToHeight = img_OriginalImage.Height*i_width/img_OriginalImage.Width;
break;
case "H" : //指定高度，宽度按照比例缩放
i_ToWidth = img_OriginalImage.Width*i_Height/img_OriginalImage.Height;
break;
case "CUT" : //按照指定的高度和宽度剪裁（不变形）
if ((double)img_OriginalImage.Width/(double)img_OriginalImage.Height > (double)i_ToWidth/(double)i_ToHeight)
{
i_OriginalHeight = img_OriginalImage.Height;
i_OriginalWidth = img_OriginalImage.Height*i_ToWidth/i_ToHeight;
y = 0;
x = (img_OriginalImage.Width-i_OriginalWidth)/2;
}
else
{
i_OriginalWidth = img_OriginalImage.Width;
i_OriginalHeight = img_OriginalImage.Width*i_Height/i_ToWidth;
x = 0;
y = (img_OriginalImage.Height-i_OriginalHeight)/2;
}
break;
default:
break;
}
//新建一个BMP图片
Image img_BitMap = new System.Drawing.Bitmap(i_ToWidth,i_ToHeight);
//新建一个画板
System.Drawing.Graphics gp = new System.Drawing.Graphics.FromImage(img_BitMap);
//设置高质量插值法
gp.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
//设置高质量、低速度呈现平滑程度
gp.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//清空画布并以透明背景色填充
gp.Clear(Color.Transparent);
//指定位置并按大小绘制原图片的指定部分
gp.DrawImage(img_OriginalImage,new Rectangle(0,0,i_ToWidth,i_ToHeight),new Rectangle(x,y,i_OrignalWidth,i_OriginalHeight),GraphicsUnit.Pixel);
try
{
//以JPG格式保存图片
img_BitMap.Save(str_ThumbnailPath,System.Drawing.Imaging.ImageFormat.Jpeg);
}
catch(Exception e)
{
throw e;
}
finally
{
img_OriginalImage.Dispose();
img_BitMap.Dispose();
gp.Dispose();
}
}
#endregion
posted @ 2010-10-09 12:41 飛魚V 阅读(148) 评论(0)
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