简单的C#进行图片操作
最近做东西,需要在一个服务器已经存在的图片上,在上面画一些标注(只是简单的圆形矩形文字之类)。以前倒还真没有做过图形操作,不过听说挺简单的。就问了一下,大家说使用Graphics类。
那么,就可以简单得到下面的代码了。
1 // 得到图片
2 System.Drawing.Image img = System.Drawing.Image.FromFile ( this.TextBox1.Text );
3 Graphics g = Graphics.FromImage ( img );
4 Pen p = new Pen ( Color.White, 2 );
5 g.DrawImage ( img, 10, 10 );
6
7 // 画圆和文字
8 g.DrawEllipse ( p, 10, 10, 5, 5 );
9 g.DrawString ( "这里是圆", new Font ( "宋体", 9 ), Brushes.White, new PointF ( 20, 20 ) );
10
11 // 填充一个圆
12 g.FillEllipse ( Brushes.White, 10, 10, 5, 5 );
13
14 // 显示到页面上,不生成真正的文件
15 Response.ContentType = "image/gif";
16 img.Save ( Response.OutputStream, ImageFormat.Jpeg );
这样在页面上就显示一个图片了。并且画了一个圆。2 System.Drawing.Image img = System.Drawing.Image.FromFile ( this.TextBox1.Text );
3 Graphics g = Graphics.FromImage ( img );
4 Pen p = new Pen ( Color.White, 2 );
5 g.DrawImage ( img, 10, 10 );
6
7 // 画圆和文字
8 g.DrawEllipse ( p, 10, 10, 5, 5 );
9 g.DrawString ( "这里是圆", new Font ( "宋体", 9 ), Brushes.White, new PointF ( 20, 20 ) );
10
11 // 填充一个圆
12 g.FillEllipse ( Brushes.White, 10, 10, 5, 5 );
13
14 // 显示到页面上,不生成真正的文件
15 Response.ContentType = "image/gif";
16 img.Save ( Response.OutputStream, ImageFormat.Jpeg );
PS:用一个笨方法把多个图合并到一个图里面:
1// 合并四张图
2// 96*96的图
3System.Drawing.Image imgBig = System.Drawing.Image.FromFile ( "c:\\qcd_logo2.PNG" );
4// 48*48的图
5System.Drawing.Image img = System.Drawing.Image.FromFile ( "c:\\qcd_logo.bmp" );
6Graphics g = Graphics.FromImage ( imgBig );
7g.DrawImage ( img, 0, 0 );
8g.DrawImage ( img, 49, 0 );
9g.DrawImage ( img, 0, 49 );
10g.DrawImage ( img, 49, 49 );
2// 96*96的图
3System.Drawing.Image imgBig = System.Drawing.Image.FromFile ( "c:\\qcd_logo2.PNG" );
4// 48*48的图
5System.Drawing.Image img = System.Drawing.Image.FromFile ( "c:\\qcd_logo.bmp" );
6Graphics g = Graphics.FromImage ( imgBig );
7g.DrawImage ( img, 0, 0 );
8g.DrawImage ( img, 49, 0 );
9g.DrawImage ( img, 0, 49 );
10g.DrawImage ( img, 49, 49 );
PS2:用一个方法截取合并后的图
1// 144*144的图
2 System.Drawing.Image imgBig = System.Drawing.Image.FromFile ( "c:\\qcd_logo2.PNG" );
3// 48*48的图
4 System.Drawing.Image img = System.Drawing.Image.FromFile ( "c:\\qcd_logo.bmp" );
5 Graphics g = Graphics.FromImage ( imgBig );
6 Pen p = new Pen ( Color.Red, 2 );
7// 全部合并,即3*3
8 g.DrawImage ( img, 0, 0 );
9 g.DrawImage ( img, 49, 0 );
10 g.DrawImage ( img, 0, 49 );
11 g.DrawImage ( img, 49, 49 );
12 g.DrawImage ( img, 97, 0 );
13 g.DrawImage ( img, 0, 97 );
14 g.DrawImage ( img, 97, 97 );
15 g.DrawImage ( img, 49, 97 );
16 g.DrawImage ( img, 97, 49 );
17 g.DrawEllipse ( p, 49, 49, 10, 10 );
18 g.DrawString ( "这是圆", new Font ( "宋体", 9 ), Brushes.Red, new PointF ( 55, 55 ) );
19
20// 切换到小图
21 g = Graphics.FromImage ( img );
22 // 截取的大图范围
23 Rectangle rect = new Rectangle ( 49, 49, 48, 48 );
24// 截取大图
25 g.DrawImage ( imgBig, 0, 0, rect, GraphicsUnit.Pixel );
26
27 // 显示到页面上,不生成真正的文件
28 Response.ContentType = "image/gif";
29 img.Save ( Response.OutputStream, ImageFormat.Jpeg );
2 System.Drawing.Image imgBig = System.Drawing.Image.FromFile ( "c:\\qcd_logo2.PNG" );
3// 48*48的图
4 System.Drawing.Image img = System.Drawing.Image.FromFile ( "c:\\qcd_logo.bmp" );
5 Graphics g = Graphics.FromImage ( imgBig );
6 Pen p = new Pen ( Color.Red, 2 );
7// 全部合并,即3*3
8 g.DrawImage ( img, 0, 0 );
9 g.DrawImage ( img, 49, 0 );
10 g.DrawImage ( img, 0, 49 );
11 g.DrawImage ( img, 49, 49 );
12 g.DrawImage ( img, 97, 0 );
13 g.DrawImage ( img, 0, 97 );
14 g.DrawImage ( img, 97, 97 );
15 g.DrawImage ( img, 49, 97 );
16 g.DrawImage ( img, 97, 49 );
17 g.DrawEllipse ( p, 49, 49, 10, 10 );
18 g.DrawString ( "这是圆", new Font ( "宋体", 9 ), Brushes.Red, new PointF ( 55, 55 ) );
19
20// 切换到小图
21 g = Graphics.FromImage ( img );
22 // 截取的大图范围
23 Rectangle rect = new Rectangle ( 49, 49, 48, 48 );
24// 截取大图
25 g.DrawImage ( imgBig, 0, 0, rect, GraphicsUnit.Pixel );
26
27 // 显示到页面上,不生成真正的文件
28 Response.ContentType = "image/gif";
29 img.Save ( Response.OutputStream, ImageFormat.Jpeg );