Util.cs 的部分代码:
1
/// <summary>
2
/// 创建缩略图
3
/// </summary>
4
/// <param name="src">来源页面
5
/// 可以是相对地址或者绝对地址
6
/// </param>
7
/// <param name="width">缩略图宽度</param>
8
/// <param name="height">缩略图高度</param>
9
/// <returns>字节数组</returns>
10
public static byte[] MakeThumbnail(string src, double width, double height)
11
{
12
Image image;
13![](/Images/OutliningIndicators/InBlock.gif)
14
// 相对路径从本机直接读取
15
if (src.ToLower().IndexOf("http://") == -1)
16
{
17
src = HttpContext.Current.Server.MapPath(src);
18
image = Image.FromFile(src, true);
19
}
20
else // 绝对路径从 Http 读取
21
{
22
HttpWebRequest req = (HttpWebRequest) WebRequest.Create(src);
23
req.Method = "GET";
24
HttpWebResponse resp = (HttpWebResponse) req.GetResponse();
25
Stream receiveStream = resp.GetResponseStream();
26
image = Image.FromStream(receiveStream);
27
resp.Close();
28
receiveStream.Close();
29
}
30
double newWidth, newHeight;
31
if (image.Width > image.Height)
32
{
33
newWidth = width;
34
newHeight = image.Height*(newWidth/image.Width);
35
}
36
else
37
{
38
newHeight = height;
39
newWidth = (newHeight/image.Height)*image.Width;
40
}
41
if (newWidth > width)
42
{
43
newWidth = width;
44
}
45
if (newHeight > height)
46
{
47
newHeight = height;
48
}
49
//取得图片大小
50
Size size = new Size((int) newWidth, (int) newHeight);
51
//新建一个bmp图片
52
Image bitmap = new Bitmap(size.Width, size.Height);
53
//新建一个画板
54
Graphics g = Graphics.FromImage(bitmap);
55
//设置高质量插值法
56
g.InterpolationMode = InterpolationMode.High;
57
//设置高质量,低速度呈现平滑程度
58
g.SmoothingMode = SmoothingMode.HighQuality;
59
//清空一下画布
60
g.Clear(Color.White);
61
//在指定位置画图
62
g.DrawImage(image, new Rectangle(0, 0, bitmap.Width, bitmap.Height),
63
new Rectangle(0, 0, image.Width, image.Height),
64
GraphicsUnit.Pixel);
65
///文字水印
66
//System.Drawing.Graphics G=System.Drawing.Graphics.FromImage(bitmap);
67
//System.Drawing.Font f=new Font("宋体",10);
68
//System.Drawing.Brush b=new SolidBrush(Color.Black);
69
//G.DrawString("myohmine",f,b,10,10);
70
//G.Dispose();
71
///图片水印
72
//System.Drawing.Image copyImage = System.Drawing.Image.FromFile(System.Web.HttpContext.Current.Server.MapPath("pic/1.gif"));
73
//Graphics a = Graphics.FromImage(bitmap);
74
//a.DrawImage(copyImage, new Rectangle(bitmap.Width-copyImage.Width,bitmap.Height-copyImage.Height,copyImage.Width, copyImage.Height),0,0, copyImage.Width, copyImage.Height, GraphicsUnit.Pixel);
75
//copyImage.Dispose();
76
//a.Dispose();
77
//copyImage.Dispose();
78
//保存高清晰度的缩略图
79
MemoryStream stream = new MemoryStream();
80
bitmap.Save(stream, ImageFormat.Jpeg);
81
byte[] buffer = stream.GetBuffer();
82
g.Dispose();
83
image.Dispose();
84
bitmap.Dispose();
85
return buffer;
86
}
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
2
![](/Images/OutliningIndicators/InBlock.gif)
3
![](/Images/OutliningIndicators/InBlock.gif)
4
![](/Images/OutliningIndicators/InBlock.gif)
5
![](/Images/OutliningIndicators/InBlock.gif)
6
![](/Images/OutliningIndicators/InBlock.gif)
7
![](/Images/OutliningIndicators/InBlock.gif)
8
![](/Images/OutliningIndicators/InBlock.gif)
9
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
10
![](/Images/OutliningIndicators/None.gif)
11
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
12
![](/Images/OutliningIndicators/InBlock.gif)
13
![](/Images/OutliningIndicators/InBlock.gif)
14
![](/Images/OutliningIndicators/InBlock.gif)
15
![](/Images/OutliningIndicators/InBlock.gif)
16
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
17
![](/Images/OutliningIndicators/InBlock.gif)
18
![](/Images/OutliningIndicators/InBlock.gif)
19
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
20
![](/Images/OutliningIndicators/InBlock.gif)
21
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
22
![](/Images/OutliningIndicators/InBlock.gif)
23
![](/Images/OutliningIndicators/InBlock.gif)
24
![](/Images/OutliningIndicators/InBlock.gif)
25
![](/Images/OutliningIndicators/InBlock.gif)
26
![](/Images/OutliningIndicators/InBlock.gif)
27
![](/Images/OutliningIndicators/InBlock.gif)
28
![](/Images/OutliningIndicators/InBlock.gif)
29
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
30
![](/Images/OutliningIndicators/InBlock.gif)
31
![](/Images/OutliningIndicators/InBlock.gif)
32
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
33
![](/Images/OutliningIndicators/InBlock.gif)
34
![](/Images/OutliningIndicators/InBlock.gif)
35
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
36
![](/Images/OutliningIndicators/InBlock.gif)
37
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
38
![](/Images/OutliningIndicators/InBlock.gif)
39
![](/Images/OutliningIndicators/InBlock.gif)
40
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
41
![](/Images/OutliningIndicators/InBlock.gif)
42
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
43
![](/Images/OutliningIndicators/InBlock.gif)
44
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
45
![](/Images/OutliningIndicators/InBlock.gif)
46
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
47
![](/Images/OutliningIndicators/InBlock.gif)
48
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
49
![](/Images/OutliningIndicators/InBlock.gif)
50
![](/Images/OutliningIndicators/InBlock.gif)
51
![](/Images/OutliningIndicators/InBlock.gif)
52
![](/Images/OutliningIndicators/InBlock.gif)
53
![](/Images/OutliningIndicators/InBlock.gif)
54
![](/Images/OutliningIndicators/InBlock.gif)
55
![](/Images/OutliningIndicators/InBlock.gif)
56
![](/Images/OutliningIndicators/InBlock.gif)
57
![](/Images/OutliningIndicators/InBlock.gif)
58
![](/Images/OutliningIndicators/InBlock.gif)
59
![](/Images/OutliningIndicators/InBlock.gif)
60
![](/Images/OutliningIndicators/InBlock.gif)
61
![](/Images/OutliningIndicators/InBlock.gif)
62
![](/Images/OutliningIndicators/InBlock.gif)
63
![](/Images/OutliningIndicators/InBlock.gif)
64
![](/Images/OutliningIndicators/InBlock.gif)
65
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
66
![](/Images/OutliningIndicators/InBlock.gif)
67
![](/Images/OutliningIndicators/InBlock.gif)
68
![](/Images/OutliningIndicators/InBlock.gif)
69
![](/Images/OutliningIndicators/InBlock.gif)
70
![](/Images/OutliningIndicators/InBlock.gif)
71
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
72
![](/Images/OutliningIndicators/InBlock.gif)
73
![](/Images/OutliningIndicators/InBlock.gif)
74
![](/Images/OutliningIndicators/InBlock.gif)
75
![](/Images/OutliningIndicators/InBlock.gif)
76
![](/Images/OutliningIndicators/InBlock.gif)
77
![](/Images/OutliningIndicators/InBlock.gif)
78
![](/Images/OutliningIndicators/InBlock.gif)
79
![](/Images/OutliningIndicators/InBlock.gif)
80
![](/Images/OutliningIndicators/InBlock.gif)
81
![](/Images/OutliningIndicators/InBlock.gif)
82
![](/Images/OutliningIndicators/InBlock.gif)
83
![](/Images/OutliningIndicators/InBlock.gif)
84
![](/Images/OutliningIndicators/InBlock.gif)
85
![](/Images/OutliningIndicators/InBlock.gif)
86
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
专门输出缩略图的页面 Thumbnail.aspx.cs 代码:
1
namespace JCDWeb
2
{
3
using System;
4
using System.Web.UI;
5![](/Images/OutliningIndicators/InBlock.gif)
6
public class Thumbnail : Page
7
{
8
private void Page_Load(object sender, EventArgs e)
9
{
10
string src = GetQueryStringSrc();
11
double width = GetQueryStringWidth();
12
double height = GetQueryStringHeight();
13![](/Images/OutliningIndicators/InBlock.gif)
14
Response.ContentType = "image/jpeg";
15
Response.Clear();
16![](/Images/OutliningIndicators/InBlock.gif)
17
if (src.Length > 0 && width > 0 && height > 0)
18
{
19
try
20
{
21
byte[] buffer = Util.MakeThumbnail(src, width, height);
22
Response.BinaryWrite(buffer);
23
Response.Flush();
24
}
25
catch
26
{
27![](/Images/OutliningIndicators/InBlock.gif)
28
}
29
}
30
}
31![](/Images/OutliningIndicators/InBlock.gif)
32
handle query string
72![](/Images/OutliningIndicators/InBlock.gif)
73
Web Forms Designer generated code
87
}
88
}
![](/Images/OutliningIndicators/None.gif)
2
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
3
![](/Images/OutliningIndicators/InBlock.gif)
4
![](/Images/OutliningIndicators/InBlock.gif)
5
![](/Images/OutliningIndicators/InBlock.gif)
6
![](/Images/OutliningIndicators/InBlock.gif)
7
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
8
![](/Images/OutliningIndicators/InBlock.gif)
9
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
10
![](/Images/OutliningIndicators/InBlock.gif)
11
![](/Images/OutliningIndicators/InBlock.gif)
12
![](/Images/OutliningIndicators/InBlock.gif)
13
![](/Images/OutliningIndicators/InBlock.gif)
14
![](/Images/OutliningIndicators/InBlock.gif)
15
![](/Images/OutliningIndicators/InBlock.gif)
16
![](/Images/OutliningIndicators/InBlock.gif)
17
![](/Images/OutliningIndicators/InBlock.gif)
18
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
19
![](/Images/OutliningIndicators/InBlock.gif)
20
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
21
![](/Images/OutliningIndicators/InBlock.gif)
22
![](/Images/OutliningIndicators/InBlock.gif)
23
![](/Images/OutliningIndicators/InBlock.gif)
24
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
25
![](/Images/OutliningIndicators/InBlock.gif)
26
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
27
![](/Images/OutliningIndicators/InBlock.gif)
28
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
29
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
30
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
31
![](/Images/OutliningIndicators/InBlock.gif)
32
![](/Images/OutliningIndicators/ContractedSubBlock.gif)
72
![](/Images/OutliningIndicators/InBlock.gif)
73
![](/Images/OutliningIndicators/ContractedSubBlock.gif)
87
![](/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
88
![](/Images/OutliningIndicators/ExpandedBlockEnd.gif)
调用方法:
相对地址:
Thumbnail.aspx?width=200&height=300&src=upload/test.jpg
绝对地址:
Thumbnail.aspx?width=200&height=300&src=http://www.test.com/upload/test.jpg