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using
System;
using
System.Data;
using
System.Data.SqlClient;
using
System.Configuration;
using
System.Web;
using
System.Web.Security;
using
System.Web.UI;
using
System.Web.UI.WebControls;
using
System.Web.UI.WebControls.WebParts;
using
System.Web.UI.HtmlControls;
using
System.Text;
using
System.Text.RegularExpressions;
using
System.Drawing;
using
System.Drawing.Imaging;
using
System.Collections;
using
System.ComponentModel;
namespace
Legalsoft.Images
{
/// <summary>
/// News 的摘要说明
/// </summary>
public
class
XImage
{
public
Color tBackground;
public
Color tBorder;
public
Color tShadow;
public
int
tQuality;
public
string
markPosition;
/// <summary>
/// 图片参数预定义
/// </summary>
static
Hashtable htmimes =
new
Hashtable();
internal
readonly
string
AllowExt =
".jpe|.jpeg|.jpg|.png|.tif|.tiff|.bmp|.gif"
;
public
XImage()
{
tBackground = Color.Transparent;
tBorder = Color.Transparent;
tShadow = Color.Transparent;
tQuality = 100;
markPosition =
"左下角"
;
#region 图片类型预定义
htmimes[
".jpe"
]=
"image/jpeg"
;
htmimes[
".jpeg"
] =
"image/jpeg"
;
htmimes[
".jpg"
] =
"image/jpeg"
;
htmimes[
".png"
] =
"image/png"
;
htmimes[
".tif"
] =
"image/tiff"
;
htmimes[
".tiff"
] =
"image/tiff"
;
htmimes[
".bmp"
] =
"image/bmp"
;
htmimes[
".gif"
] =
"image/gif"
;
#endregion
}
#region 下载指定URL图片并保存
/// <summary>
/// 下载指定URL的文件并保存到指定目录
/// </summary>
/// <param name="strUrl"></param>
public
void
DownloadImage(
string
strUrl,
string
file)
{
System.Net.WebClient wc =
new
System.Net.WebClient();
wc.DownloadFile(strUrl, file);
}
#endregion
#region C#自动生成缩略图
/// <summary>
/// 按给定名字确定颜色
/// </summary>
/// <param name="name"></param>
/// <returns></returns>
public
Color ToColor(
string
name)
{
if
(name ==
"白色"
)
return
Color.White;
if
(name ==
"红色"
)
return
Color.Red;
if
(name ==
"蓝色"
)
return
Color.Blue;
if
(name ==
"绿色"
)
return
Color.Green;
if
(name ==
"黑色"
)
return
Color.Black;
if
(name ==
"灰色"
)
return
Color.DarkGray;
if
(name ==
"黄色"
)
return
Color.Yellow;
if
(name ==
"紫色"
)
return
Color.Cyan;
if
(name ==
"无色"
)
return
Color.Transparent;
return
Color.Transparent;
}
/// <summary>
/// 按名字设置各种颜色，可以自行扩充:)
/// </summary>
/// <param name="name"></param>
/// <returns></returns>
public
int
ToQuality(
string
name)
{
return
Int32.Parse(name.Replace(
"%"
,
""
));
}
/// <summary>
/// 获取图像编码解码器的所有相关信息
/// </summary>
/// <param name="mimeType">包含编码解码器的多用途网际邮件扩充协议 (MIME) 类型的字符串</param>
/// <returns>返回图像编码解码器的所有相关信息</returns>
private
static
ImageCodecInfo GetCodecInfo(
string
mimeType)
{
ImageCodecInfo[] CodecInfo = ImageCodecInfo.GetImageEncoders();
foreach
(ImageCodecInfo ici
in
CodecInfo)
{
if
(ici.MimeType == mimeType)
return
ici;
}
return
null
;
}
/// <summary>
/// 检测扩展名的有效性
/// </summary>
/// <param name="sExt">文件名扩展名</param>
/// <returns>如果扩展名有效,返回true,否则返回false.</returns>
private
bool
CheckValidExt(
string
sExt)
{
bool
flag =
false
;
string
[] aExt = AllowExt.Split(
"|"
);
foreach
(
string
filetype
in
aExt)
{
if
(filetype.ToLower() == sExt)
{
flag =
true
;
break
;
}
}
return
flag;
}
/// <summary>
/// 保存图片
/// </summary>
/// <param name="image">Image 对象</param>
/// <param name="savePath">保存路径</param>
/// <param name="ici">指定格式的编解码参数</param>
private
void
SaveImage(System.Drawing.Image image,
string
savePath, ImageCodecInfo ici)
{
//设置 原图片 对象的 EncoderParameters 对象
EncoderParameters parameters =
new
EncoderParameters(1);
parameters.Param[0] =
new
EncoderParameter(System.Drawing.Imaging.Encoder.Quality, ((
long
)tQuality));
image.Save(savePath, ici, parameters);
parameters.Dispose();
}
/// <summary>
/// 生成缩略图
/// </summary>
/// <param name="sourceImagePath">原图片路径(相对路径)</param>
/// <param name="thumbnailImagePath">生成的缩略图路径,如果为空则保存为原图片路径(相对路径)</param>
/// <param name="thumbnailImageWidth">缩略图的宽度（高度与按源图片比例自动生成）</param>
public
void
ToThumbnail(
string
sourceImagePath,
string
thumbnailImagePath,
int
thumbnailImageWidth,
int
thumbnailImageHeight )
{
// 1.先检查图片格式等信息
string
ThumbnailImagePath = thumbnailImagePath;
string
SourceImagePath = sourceImagePath;
string
sExt = SourceImagePath.Substring(SourceImagePath.LastIndexOf(
"."
)).ToLower();
if
(SourceImagePath.ToString() == System.String.Empty)
{
throw
new
NullReferenceException(
"SourceImagePath is null!"
);
}
if
(!CheckValidExt(sExt))
{
throw
new
ArgumentException(
"原图片文件格式不正确,支持的格式有[ "
+ AllowExt +
" ]"
,
"SourceImagePath"
);
}
// 从原图片创建 Image 对象
System.Drawing.Image image = System.Drawing.Image.FromFile(HttpContext.Current.Server.MapPath(SourceImagePath));
// 2.计算图片的位置、尺寸等信息
int
tWidth, tHeight, tLeft, tTop;
double
fScale = (
double
)thumbnailImageHeight / (
double
)thumbnailImageWidth;
// 高度宽度比
if
(((
double
)image.Width * fScale) > (
double
)image.Height)
// 如果原图比较宽
{
tWidth = thumbnailImageWidth;
tHeight = (
int
)((
double
)image.Height * (
double
)tWidth / (
double
)image.Width);
tLeft = 0;
tTop = (thumbnailImageHeight-tHeight)/2;
}
else
{
tHeight = thumbnailImageHeight;
tWidth = (
int
)((
double
)image.Width * (
double
)tHeight / (
double
)image.Height);
tLeft = (thumbnailImageWidth-tWidth)/2;
tTop = 0;
}
if
(tLeft < 0) tLeft = 0;
if
(tTop < 0) tTop = 0;
if
(tBorder != Color.Transparent)
{
tWidth -= 2;
tHeight -= 2;
tLeft++;
tTop++;
}
if
(tShadow != Color.Transparent)
{
tWidth -= 1;
tHeight -= 1;
}
//用指定的大小和格式初始化 Bitmap 类的新实例
//Bitmap bitmap = new Bitmap(ThumbnailImageWidth, num, PixelFormat.Format32bppArgb);
Bitmap bitmap =
new
Bitmap(thumbnailImageWidth, thumbnailImageHeight, PixelFormat.Format32bppArgb);
//从指定的 Image 对象创建新 Graphics 对象
Graphics graphics = Graphics.FromImage(bitmap);
//清除整个绘图面并以透明背景色填充
if
(tBackground != Color.Transparent)
{
graphics.Clear(tBackground);
}
else
{
graphics.Clear(Color.Transparent);
}
// 添加阴影
if
(tShadow != Color.Transparent)
{
Pen shPen =
new
Pen(tShadow);
graphics.DrawLine(shPen,
new
Point(1, thumbnailImageHeight-1),
new
Point(thumbnailImageWidth-1, thumbnailImageHeight-1));
graphics.DrawLine(shPen,
new
Point(thumbnailImageWidth-1, 1),
new
Point(thumbnailImageWidth-1, thumbnailImageHeight-1));
}
// 添加边框
if
(tBorder != Color.Transparent)
{
Pen bdPen =
new
Pen(tBorder);
if
(tShadow != Color.Transparent)
{
graphics.DrawRectangle(bdPen,
new
Rectangle(0, 0, thumbnailImageWidth-2, thumbnailImageHeight-2));
}
else
{
graphics.DrawRectangle(bdPen,
new
Rectangle(0, 0, thumbnailImageWidth-1, thumbnailImageHeight-1));
}
}
//在指定位置并且按指定大小绘制 原图片 对象
graphics.DrawImage(image,
new
Rectangle(tLeft, tTop, tWidth, tHeight));
image.Dispose();
try
{
//将此 原图片 以指定格式并用指定的编解码参数保存到指定文件
string
savepath = (ThumbnailImagePath ==
null
? SourceImagePath : ThumbnailImagePath);
SaveImage(bitmap, HttpContext.Current.Server.MapPath(savepath), GetCodecInfo((
string
)htmimes[sExt]));
}
catch
(System.Exception e)
{
throw
e;
}
finally
{
bitmap.Dispose();
graphics.Dispose();
}
}
#endregion
#region C#给图片添加水印
public
void
Mark(
string
sourceImagePath,
string
markString)
{
// 1.先检查图片格式等信息
string
markImagePath = sourceImagePath;
string
SourceImagePath = sourceImagePath;
string
sExt = SourceImagePath.Substring(SourceImagePath.LastIndexOf(
"."
)).ToLower();
if
(SourceImagePath.ToString() == System.String.Empty)
{
throw
new
NullReferenceException(
"SourceImagePath is null!"
);
}
if
(!CheckValidExt(sExt))
{
throw
new
ArgumentException(
"原图片文件格式不正确,支持的格式有[ "
+ AllowExt +
" ]"
,
"SourceImagePath"
);
}
// 从原图片创建 Image 对象
System.Drawing.Image image = System.Drawing.Image.FromFile(HttpContext.Current.Server.MapPath(SourceImagePath));
//用指定的大小和格式初始化 Bitmap 类的新实例
Bitmap bitmap =
new
Bitmap(image.Width, image.Height, PixelFormat.Format32bppArgb);
//从指定的 Image 对象创建新 Graphics 对象
Graphics graphics = Graphics.FromImage(bitmap);
//在指定位置并且按指定大小绘制 原图片 对象
graphics.DrawImage(image,
new
Rectangle(0, 0, image.Width, image.Height));
#region 绘制水印
// 设置水印字体
int
fHeight = image.Height/5;
if
(fHeight>16) fHeight = 16;
Font drawFont =
new
Font(
"Arial"
, fHeight);
// 设置水印文字位置，默认为左下角
float
x = 4;
float
y = image.Height - drawFont.Height - 4;
if
(markPosition ==
"左上角"
)
{
y = 4;
}
if
(markPosition ==
"右上角"
)
{
x = image.Width - markString.Length * fHeight / 2 - fHeight;
y = 4;
}
if
(markPosition ==
"右下角"
)
{
x = image.Width - markString.Length * fHeight / 2 - fHeight;
}
if
(markPosition ==
"图片中间"
)
{
x = image.Width / 2 - markString.Length * fHeight / 2;
y = image.Height / 2 - fHeight / 2;
}
StringFormat drawFormat =
new
StringFormat();
drawFormat.FormatFlags = StringFormatFlags.NoWrap;
// 设置水印文字颜色，先绘制一个黑色字作为阴影，再绘制白色字，这样比较显眼；
SolidBrush drawBrush =
new
SolidBrush(Color.Black);
graphics.DrawString(markString, drawFont, drawBrush, x, y, drawFormat);
drawBrush.Color = Color.White;
graphics.DrawString(markString, drawFont, drawBrush, x-1, y-1, drawFormat);
#endregion
image.Dispose();
try
{
//将此 原图片 以指定格式并用指定的编解码参数保存到指定文件
string
savepath = SourceImagePath;
SaveImage(bitmap, HttpContext.Current.Server.MapPath(savepath), GetCodecInfo((
string
)htmimes[sExt]));
}
catch
(System.Exception e)
{
throw
e;
}
finally
{
bitmap.Dispose();
graphics.Dispose();
}
}
#endregion
}
}
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本文转自曾祥展博客园博客，原文链接http://www.cnblogs.com/zengxiangzhan/archive/2009/12/31/1636549.html，如需转载请自行联系原作者
