图片操作：生成缩略图、添加水印、截取图片等

usingSystem;
usingSystem.Drawing;
usingSystem.Drawing.Imaging;
usingSystem.IO;
usingSystem.Web;

namespaceXXXX.Common
{
///<summary>
///图片操作：生成缩略图、添加水印、截取图片等
///</summary>
publicclassImagesHelper
{



///<summary>
///根据文件流获得图片宽度
///</summary>
///<paramname="file"></param>
///<returns></returns>
publicstaticintgetImgWidth(Streamstream)
{
Imageimg=Image.FromStream(stream);
intresult=img.Width;
img.Dispose();
stream.Dispose();
returnresult;
}

///<summary>
///根据图片路径获得图片宽度
///</summary>
///<paramname="filePath"></param>
///<returns></returns>
publicstaticintgetImgWidth(stringfilePath)
{
Imageimg=Image.FromFile(filePath);
intresult=img.Width;
img.Dispose();
returnresult;
}


#region从文件流生成缩略图
///<summary>
///从文件流生成缩略图
///</summary>
///<paramname="stream">数据IO流</param>
///<paramname="savePath"></param>
///<paramname="width"></param>
///<paramname="height"></param>
///<paramname="scale"></param>
///<returns></returns>
publicstaticboolGetThumbNail(Streamstream,stringsavePath,intwidth,intheight,ThumbNailScalescale)
{
//缩略图
Imageimg=Image.FromStream(stream);
stream.Dispose();
inttowidth=width;
inttoheight=height;
intx=0;
inty=0;
intow=img.Width;
intoh=img.Height;
//如果图片小于指定宽度
if(ow<width)
width=ow;

if(oh<height)
height=oh;


switch(scale)
{
caseThumbNailScale.Appointed:
break;
caseThumbNailScale.ScaleWidth:
toheight=img.Height*width/img.Width;
break;
caseThumbNailScale.ScaleHeight:
towidth=img.Width*height/img.Height;
break;
caseThumbNailScale.Cut:
if((double)img.Width/(double)img.Height>(double)towidth/(double)toheight)
{
oh=img.Height;
ow=img.Height*towidth/toheight;
y=0;
x=(img.Width-ow)/2;
}
else
{
ow=img.Width;
oh=img.Width*height/towidth;
x=0;
y=(img.Height-oh)/2;
}
break;
caseThumbNailScale.ScaleDown:
doubleTw,Th;
Tw=width;
Th=height*(Convert.ToDouble(oh)/Convert.ToDouble(ow));
if(Th>height)
{
Th=height;
Tw=width*(Convert.ToDouble(ow)/Convert.ToDouble(oh));
}
towidth=Convert.ToInt32(Tw);
toheight=Convert.ToInt32(Th);
break;
default:
break;
}

//新建一个bmp图片
Imagebitmap=newBitmap(towidth,toheight);

//新建一个画板
Graphicsg=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(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(img,newRectangle(0,0,towidth,toheight),
newRectangle(x,y,ow,oh),
GraphicsUnit.Pixel);

try
{
//以jpg格式保存缩略图
bitmap.Save(savePath,ImageFormat.Jpeg);
}
catch(Exceptionex)
{
Logger.Write(string.Format("从文件流生成缩略图：{0}",ex.Message),Logger.MsgType.Error);
returnfalse;
}
finally
{
img.Dispose();
bitmap.Dispose();
g.Dispose();
}

returntrue;
}
#endregion

#region从文件路径生成缩略图
///<summary>
///从图片路径生成缩略图
///</summary>
///<paramname="originalImagePath">图片路径</param>
///<paramname="savePath">保存路径</param>
///<paramname="width">缩略图宽度</param>
///<paramname="height">缩略图高度</param>
///<paramname="mode">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>
///<returns></returns>
publicstaticboolGetThumbNail(stringoriginalImagePath,stringsavePath,intwidth,intheight,ThumbNailScalescale)
{
//缩略图
Imageimg=Image.FromFile(originalImagePath);

inttowidth=width;
inttoheight=height;

intx=0;
inty=0;
intow=img.Width;
intoh=img.Height;

//如果图片小于指定宽度
if(ow<width)
width=ow;

switch(scale)
{
caseThumbNailScale.Appointed:
break;
caseThumbNailScale.ScaleWidth:
toheight=img.Height*width/img.Width;
break;
caseThumbNailScale.ScaleHeight:
towidth=img.Width*height/img.Height;
break;
caseThumbNailScale.Cut:
if((double)img.Width/(double)img.Height>(double)towidth/(double)toheight)
{
oh=img.Height;
ow=img.Height*towidth/toheight;
y=0;
x=(img.Width-ow)/2;
}
else
{
ow=img.Width;
oh=img.Width*height/towidth;
x=0;
y=(img.Height-oh)/2;
}
break;
caseThumbNailScale.ScaleDown:
doubleTw,Th;
Tw=width;
Th=height*(Convert.ToDouble(oh)/Convert.ToDouble(ow));
if(Th>height)
{
Th=height;
Tw=width*(Convert.ToDouble(ow)/Convert.ToDouble(oh));
}
towidth=Convert.ToInt32(Tw);
toheight=Convert.ToInt32(Th);
break;
default:
break;
}

//新建一个bmp图片
Imagebitmap=newBitmap(towidth,toheight);

//新建一个画板
Graphicsg=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(Color.White);

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

try
{
//以jpg格式保存缩略图
bitmap.Save(savePath,ImageFormat.Jpeg);
}
catch(Exceptione)
{
throwe;
}
finally
{
img.Dispose();
bitmap.Dispose();
g.Dispose();
}

returntrue;

}
#endregion

#region获取图片格式
///<summary>
///获取图片格式
///</summary>
///<paramname="strContentType"></param>
///<returns>返回图片格式</returns>
publicstaticImageFormatGetImageType(objectstrContentType)
{
if((strContentType.ToString().ToLower())=="image/pjpeg")
{
returnImageFormat.Jpeg;
}
elseif((strContentType.ToString().ToLower())=="image/gif")
{
returnImageFormat.Gif;
}
elseif((strContentType.ToString().ToLower())=="image/bmp")
{
returnImageFormat.Bmp;
}
elseif((strContentType.ToString().ToLower())=="image/tiff")
{
returnImageFormat.Tiff;
}
elseif((strContentType.ToString().ToLower())=="image/x-icon")
{
returnImageFormat.Icon;
}
elseif((strContentType.ToString().ToLower())=="image/x-png")
{
returnImageFormat.Png;
}
elseif((strContentType.ToString().ToLower())=="image/x-emf")
{
returnImageFormat.Emf;
}
elseif((strContentType.ToString().ToLower())=="image/x-exif")
{
returnImageFormat.Exif;
}
elseif((strContentType.ToString().ToLower())=="image/x-wmf")
{
returnImageFormat.Wmf;
}
else
{
returnImageFormat.MemoryBmp;
}
}
#endregion

///<summary>
///生成水印图片
///</summary>
///<paramname="sourceFile"></param>
///<paramname="saveFile">保存文件路径</param>
///<returns></returns>
publicstaticboolMakeWaterImage(StreamsourceFile,stringsaveFile)
{
boolresult=false;
//水印图片
try
{
ImageimgPhoto=Image.FromStream(sourceFile);
sourceFile.Close();
sourceFile.Dispose();

intphWidth=imgPhoto.Width;
intphHeight=imgPhoto.Height;

BitmapbmPhoto=newBitmap(phWidth,phHeight,PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution,imgPhoto.VerticalResolution);

ImageimgWatermark=newBitmap(System.Web.HttpContext.Current.Server.MapPath("/images/watermark.png"));
intwmWidth=imgWatermark.Width;
intwmHeight=imgWatermark.Height;

if(phWidth>(wmWidth+100)&&phHeight>(wmHeight+100))
{
GraphicsgrPhoto=Graphics.FromImage(bmPhoto);
grPhoto.Clear(Color.White);
grPhoto.DrawImage(imgPhoto,newRectangle(0,0,phWidth,phHeight),0,0,phWidth,phHeight,GraphicsUnit.Pixel);

grPhoto.Dispose();

//添加水印图片

using(BitmapbmWatermark=newBitmap(bmPhoto))
{
bmWatermark.SetResolution(imgPhoto.HorizontalResolution,imgPhoto.VerticalResolution);
GraphicsgrWatermark=Graphics.FromImage(bmWatermark);
using(ImageAttributesimageAttributes=newImageAttributes())
{
//ColorMapcolorMap=newColorMap();
//colorMap.OldColor=Color.FromArgb(255,255,255,255);
//colorMap.NewColor=Color.FromArgb(0,0,0,0);
//ColorMap[]remapTable={colorMap};
//imageAttributes.SetRemapTable(remapTable,ColorAdjustType.Bitmap);
float[][]colorMatrixElements={newfloat[]{1.0f,0.0f,0.0f,0.0f,0.0f},newfloat[]{0.0f,1.0f,0.0f,0.0f,0.0f},newfloat[]{0.0f,0.0f,1.0f,0.0f,0.0f},newfloat[]{0.0f,0.0f,0.0f,1.0f,0.0f},newfloat[]{0.0f,0.0f,0.0f,0.0f,1.0f}};
ColorMatrixwmColorMatrix=newColorMatrix(colorMatrixElements);
imageAttributes.SetColorMatrix(wmColorMatrix,ColorMatrixFlag.Default,ColorAdjustType.Bitmap);
intxPosOfWm=((phWidth-wmWidth)-2);
intyPosOfWm=((phHeight-wmHeight)-2);
grWatermark.DrawImage(imgWatermark,newRectangle(xPosOfWm,yPosOfWm,wmWidth,wmHeight),0,0,wmWidth,wmHeight,GraphicsUnit.Pixel,imageAttributes);
}
imgPhoto=bmWatermark;
grWatermark.Dispose();
imgPhoto.Save(saveFile,ImageFormat.Jpeg);
}

result=true;
}
else
{
result=false;
}
imgWatermark.Dispose();
bmPhoto.Dispose();
imgPhoto.Dispose();
}
catch(Exceptionex)
{
Logger.Write(string.Format("生成水印图片错误:{0}",ex.Message),Logger.MsgType.Information);

try
{
ImageimgPhoto2=Image.FromStream(sourceFile);
imgPhoto2.Save(saveFile,ImageFormat.Jpeg);
imgPhoto2.Dispose();
result=true;
}
catch
{
result=false;
}
}

returnresult;

}

///<summary>
///生成水印图片
///</summary>
///<paramname="sourceFile"></param>
///<paramname="saveFile">保存文件路径</param>
///<paramname="Location">位置0-右下角1-居中2-右上角3-左下角</param>
///<returns></returns>
publicstaticboolMakeWaterImage(StreamsourceFile,stringsaveFile,ImagePositionPosition)
{
boolresult=false;
//水印图片
try
{
ImageimgPhoto=Image.FromStream(sourceFile);


intphWidth=imgPhoto.Width;
intphHeight=imgPhoto.Height;

BitmapbmPhoto=newBitmap(phWidth,phHeight,PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution,imgPhoto.VerticalResolution);

ImageimgWatermark=newBitmap(System.Web.HttpContext.Current.Server.MapPath("/images/watermark.png"));
intwmWidth=imgWatermark.Width;
intwmHeight=imgWatermark.Height;

if(phWidth>(wmWidth+100)&&phHeight>(wmHeight+100))
{
GraphicsgrPhoto=Graphics.FromImage(bmPhoto);
grPhoto.Clear(Color.White);
grPhoto.DrawImage(imgPhoto,newRectangle(0,0,phWidth,phHeight),0,0,phWidth,phHeight,GraphicsUnit.Pixel);

grPhoto.Dispose();

//添加水印图片

using(BitmapbmWatermark=newBitmap(bmPhoto))
{
bmWatermark.SetResolution(imgPhoto.HorizontalResolution,imgPhoto.VerticalResolution);
GraphicsgrWatermark=Graphics.FromImage(bmWatermark);
using(ImageAttributesimageAttributes=newImageAttributes())
{
//ColorMapcolorMap=newColorMap();
//colorMap.OldColor=Color.FromArgb(255,255,255,255);
//colorMap.NewColor=Color.FromArgb(0,0,0,0);
//ColorMap[]remapTable={colorMap};
//imageAttributes.SetRemapTable(remapTable,ColorAdjustType.Bitmap);
float[][]colorMatrixElements={newfloat[]{1.0f,0.0f,0.0f,0.0f,0.0f},newfloat[]{0.0f,1.0f,0.0f,0.0f,0.0f},newfloat[]{0.0f,0.0f,1.0f,0.0f,0.0f},newfloat[]{0.0f,0.0f,0.0f,1.0f,0.0f},newfloat[]{0.0f,0.0f,0.0f,0.0f,1.0f}};
ColorMatrixwmColorMatrix=newColorMatrix(colorMatrixElements);
imageAttributes.SetColorMatrix(wmColorMatrix,ColorMatrixFlag.Default,ColorAdjustType.Bitmap);
intxPosOfWm=0;
intyPosOfWm=0;
switch(Position)
{
caseImagePosition.BottomRight:
xPosOfWm=((phWidth-wmWidth)-2);
yPosOfWm=((phHeight-wmHeight)-2);
break;
caseImagePosition.TopLeft:
xPosOfWm=2;
yPosOfWm=2;
break;
caseImagePosition.TopRigth:
xPosOfWm=((phWidth-wmWidth)-2);
yPosOfWm=2;
break;
caseImagePosition.BottomLeft:
xPosOfWm=2;
yPosOfWm=((phHeight-wmHeight)-2);
break;
caseImagePosition.Center:
xPosOfWm=((phWidth/2)-(wmWidth/2));
yPosOfWm=((phHeight/2)-(wmHeight/2));
break;
}
grWatermark.DrawImage(imgWatermark,newRectangle(xPosOfWm,yPosOfWm,wmWidth,wmHeight),0,0,wmWidth,wmHeight,GraphicsUnit.Pixel,imageAttributes);
}
imgPhoto=bmWatermark;
grWatermark.Dispose();
imgPhoto.Save(saveFile,ImageFormat.Jpeg);
}

result=true;
}
else
{
ImageimgPhoto2=Image.FromStream(sourceFile);
imgPhoto2.Save(saveFile,ImageFormat.Jpeg);
imgPhoto2.Dispose();
result=true;
}
imgWatermark.Dispose();
bmPhoto.Dispose();
imgPhoto.Dispose();
}
catch
{

try
{
ImageimgPhoto2=Image.FromStream(sourceFile);
imgPhoto2.Save(saveFile,ImageFormat.Jpeg);
imgPhoto2.Dispose();
result=true;
}
catch
{
result=false;
}
}

sourceFile.Close();
sourceFile.Dispose();

returnresult;

}

#region从图片中截取一张指定大小的图片
///<summary>
///从图片中截取部分生成新图
///</summary>
///<paramname="sFromFilePath">原始图片</param>
///<paramname="saveFilePath">生成新图</param>
///<paramname="width">截取图片宽度</param>
///<paramname="height">截取图片高度</param>
///<paramname="spaceX">截图图片X坐标</param>
///<paramname="spaceY">截取图片Y坐标</param>
publicstaticvoidCaptureImage(stringsFromFilePath,stringsaveFilePath,intwidth,intheight,intspaceX,intspaceY)
{
//载入底图
ImagefromImage=Image.FromFile(sFromFilePath);
intx=0;//截取X坐标
inty=0;//截取Y坐标
//原图宽与生成图片宽之差
//当小于0(即原图宽小于要生成的图)时，新图宽度为较小者即原图宽度X坐标则为0
//当大于0(即原图宽大于要生成的图)时，新图宽度为设置值即widthX坐标则为sX与spaceX之间较小者
//Y方向同理
intsX=fromImage.Width-width;
intsY=fromImage.Height-height;
if(sX>0)
{
x=sX>spaceX?spaceX:sX;
}
else
{
width=fromImage.Width;
}
if(sY>0)
{
y=sY>spaceY?spaceY:sY;
}
else
{
height=fromImage.Height;
}

//创建新图位图
Bitmapbitmap=newBitmap(width,height);
//创建作图区域
Graphicsgraphic=Graphics.FromImage(bitmap);
//截取原图相应区域写入作图区
graphic.DrawImage(fromImage,0,0,newRectangle(x,y,width,height),GraphicsUnit.Pixel);
//从作图区生成新图
ImagesaveImage=Image.FromHbitmap(bitmap.GetHbitmap());
//保存图象
saveImage.Save(saveFilePath,ImageFormat.Jpeg);
//释放资源
saveImage.Dispose();
bitmap.Dispose();
graphic.Dispose();
}
#endregion

publicenumImagePosition
{
///<summary>
///居中
///</summary>
Center,
///<summary>
///左上角
///</summary>
TopLeft,
///<summary>
///左下角
///</summary>
BottomLeft,
///<summary>
///右下角
///</summary>
BottomRight,
///<summary>
///右上角
///</summary>
TopRigth
}

///<summary>
///图片
///</summary>
publicenumThumbNailScale
{
///<summary>
///指定高宽缩放，图片长宽不一致会变形
///</summary>
Appointed,
///<summary>
///指定宽，高按比例
///</summary>
ScaleWidth,
///<summary>
///指定高，宽按比例
///</summary>
ScaleHeight,
///<summary>
///指定高宽裁减，可能只显示部分图片
///</summary>
Cut,
///<summary>
///按图片比例缩放，不变形，显示全部图片（推荐）
///</summary>
ScaleDown
}
}
}