C#给图片添加水印完整实例
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2022-06-25 08:56:19
本文实例讲述了c#给图片添加水印的方法。分享给大家供大家参考,具体如下:
using system;
using system.data;
using sys...
本文实例讲述了c#给图片添加水印的方法。分享给大家供大家参考,具体如下:
using system; using system.data; 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.drawing; using system.io; using system.drawing.imaging; /// <summary> ///imgwater 的摘要说明 /// </summary> public class imgwater { public imgwater() { // //todo: 在此处添加构造函数逻辑 // } /// <summary> /// 图片水印 /// </summary> /// <param name="imgfile">原图文件地址</param> /// <param name="waterimg">水印图片地址</param> /// <param name="simgpath">水印图片保存地址</param> /// <param name="alpha">水印透明度设置</param> /// <param name="iscale">水印图片在原图上的显示比例</param> /// <param name="intdistance">水印图片在原图上的边距确定,以图片的右边和下边为准,当设定的边距超过一定大小后参数会自动失效</param> public bool zzsimgwater( string imgfile , string waterimg , string simgpath , float alpha , float iscale , int intdistance ) { try { //装载图片 filestream fs = new filestream(imgfile, filemode.open); binaryreader br = new binaryreader(fs); byte[] bytes = br.readbytes((int)fs.length); br.close(); fs.close(); memorystream ms = new memorystream(bytes); system.drawing.image imgphoto = system.drawing.image.fromstream(ms); //system.drawing.image imgphoto = system.drawing.image.fromfile(imgfile); int imgphotowidth = imgphoto.width; int imgphotoheight = imgphoto.height; system.drawing.image imgwatermark = new bitmap(waterimg); int imgwatermarkwidth = imgwatermark.width; int imgwatermarkheight = imgwatermark.height; //计算水印图片尺寸 decimal ascale = convert.todecimal(iscale); decimal pscale = 0.05m; decimal minscale = ascale - pscale; decimal maxscale = ascale + pscale; int imgwatermarkwidthnew = imgwatermarkwidth; int imgwatermarkheightnew = imgwatermarkheight; if (imgphotowidth >= imgwatermarkwidth && imgphotoheight >= imgwatermarkheight && imgphotowidth >= imgphotoheight) if (imgwatermarkwidth > imgwatermarkheight) if ((minscale <= math.round((convert.todecimal(imgwatermarkwidth) / convert.todecimal(imgphotowidth)), 7)) && (math.round((convert.todecimal(imgwatermarkwidth) / convert.todecimal(imgphotowidth)), 7) <= maxscale)) { } else { imgwatermarkwidthnew = convert.toint32(imgphotowidth * ascale); imgwatermarkheightnew = convert.toint32((imgphotowidth * ascale / imgwatermarkwidth) * imgwatermarkheight); } else if ((minscale <= math.round((convert.todecimal(imgwatermarkheight) / convert.todecimal(imgphotoheight)), 7)) && (math.round((convert.todecimal(imgwatermarkheight) / convert.todecimal(imgphotoheight)), 7) <= maxscale)) { } else { imgwatermarkheightnew = convert.toint32(imgphotoheight * ascale); imgwatermarkwidthnew = convert.toint32((imgphotoheight * ascale / imgwatermarkheight) * imgwatermarkwidth); } if (imgwatermarkwidth >= imgphotowidth && imgwatermarkheight >= imgphotoheight && imgwatermarkwidth >= imgwatermarkheight) { imgwatermarkwidthnew = convert.toint32(imgphotowidth * ascale); imgwatermarkheightnew = convert.toint32(((imgphotowidth * ascale) / imgwatermarkwidth) * imgwatermarkheight); } if (imgwatermarkwidth >= imgphotowidth && imgwatermarkheight <= imgphotoheight && imgphotowidth >= imgphotoheight) { imgwatermarkwidthnew = convert.toint32(imgphotowidth * ascale); imgwatermarkheightnew = convert.toint32(((imgphotowidth * ascale) / imgwatermarkwidth) * imgwatermarkheight); } if (imgwatermarkwidth <= imgphotowidth && imgwatermarkheight >= imgphotoheight && imgphotowidth >= imgphotoheight) { imgwatermarkheightnew = convert.toint32(imgphotoheight * ascale); imgwatermarkwidthnew = convert.toint32(((imgphotoheight * ascale) / imgwatermarkheight) * imgwatermarkwidth); } if (imgphotowidth >= imgwatermarkwidth && imgphotoheight >= imgwatermarkheight && imgphotowidth <= imgphotoheight) if (imgwatermarkwidth > imgwatermarkheight) if ((minscale <= math.round((convert.todecimal(imgwatermarkwidth) / convert.todecimal(imgphotowidth)), 7)) && (math.round((convert.todecimal(imgwatermarkwidth) / convert.todecimal(imgphotowidth)), 7) <= maxscale)) { } else { imgwatermarkwidthnew = convert.toint32(imgphotowidth * ascale); imgwatermarkheightnew = convert.toint32(((imgphotowidth * ascale) / imgwatermarkwidth) * imgwatermarkheight); } else if ((minscale <= math.round((convert.todecimal(imgwatermarkheight) / convert.todecimal(imgphotoheight)), 7)) && (math.round((convert.todecimal(imgwatermarkheight) / convert.todecimal(imgphotoheight)), 7) <= maxscale)) { } else { imgwatermarkheightnew = convert.toint32(imgphotoheight * ascale); imgwatermarkwidthnew = convert.toint32(((imgphotoheight * ascale) / imgwatermarkheight) * imgwatermarkwidth); } if (imgwatermarkwidth >= imgphotowidth && imgwatermarkheight >= imgphotoheight && imgwatermarkwidth <= imgwatermarkheight) { imgwatermarkheightnew = convert.toint32(imgphotoheight * ascale); imgwatermarkwidthnew = convert.toint32(((imgphotoheight * ascale) / imgwatermarkheight) * imgwatermarkwidth); } if (imgwatermarkwidth >= imgphotowidth && imgwatermarkheight <= imgphotoheight && imgphotowidth <= imgphotoheight) { imgwatermarkwidthnew = convert.toint32(imgphotowidth * ascale); imgwatermarkheightnew = convert.toint32(((imgphotowidth * ascale) / imgwatermarkwidth) * imgwatermarkheight); } if (imgwatermarkwidth <= imgphotowidth && imgwatermarkheight >= imgphotoheight && imgphotowidth <= imgphotoheight) { imgwatermarkheightnew = convert.toint32(imgphotoheight * ascale); imgwatermarkwidthnew = convert.toint32(((imgphotoheight * ascale) / imgwatermarkheight) * imgwatermarkwidth); } //将原图画出来 bitmap bmphoto = new bitmap(imgphotowidth, imgphotoheight, system.drawing.imaging.pixelformat.format24bpprgb); bmphoto.setresolution(72, 72); graphics gbmphoto = graphics.fromimage(bmphoto); gbmphoto.interpolationmode = system.drawing.drawing2d.interpolationmode.high; gbmphoto.smoothingmode = system.drawing.drawing2d.smoothingmode.highquality; gbmphoto.clear(color.white); gbmphoto.drawimage( imgphoto , new rectangle(0, 0, imgphotowidth, imgphotoheight) , 0 , 0 , imgphotowidth , imgphotoheight , graphicsunit.pixel ); bitmap bmwatermark = new bitmap(bmphoto); bmwatermark.setresolution(imgphoto.horizontalresolution, imgphoto.verticalresolution); graphics gwatermark = graphics.fromimage(bmwatermark); //指定高质量显示水印图片质量 gwatermark.interpolationmode = system.drawing.drawing2d.interpolationmode.high; gwatermark.smoothingmode = system.drawing.drawing2d.smoothingmode.highquality; imageattributes imageattributes = new imageattributes(); //设置两种颜色,达到合成效果 colormap colormap = new colormap(); colormap.oldcolor = color.fromargb(255, 0, 255, 0); colormap.newcolor = color.fromargb(0, 0, 0, 0); colormap[] remaptable = { colormap }; imageattributes.setremaptable(remaptable, system.drawing.imaging.coloradjusttype.bitmap); //用矩阵设置水印图片透明度 float[][] colormatrixelements = { new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f}, new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f}, new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f}, new float[] {0.0f, 0.0f, 0.0f, alpha, 0.0f}, new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f} }; system.drawing.imaging.colormatrix wmcolormatrix = new system.drawing.imaging.colormatrix(colormatrixelements); imageattributes.setcolormatrix(wmcolormatrix, system.drawing.imaging.colormatrixflag.default, system.drawing.imaging.coloradjusttype.bitmap); //确定水印边距 int xpos = imgphotowidth - imgwatermarkwidthnew; int ypos = imgphotoheight - imgwatermarkheightnew; int xposofwm = 0; int yposofwm = 0; if (xpos > intdistance) xposofwm = xpos - intdistance; else xposofwm = xpos; if (ypos > intdistance) yposofwm = ypos - intdistance; else yposofwm = ypos; gwatermark.drawimage( imgwatermark , new rectangle(xposofwm, yposofwm, imgwatermarkwidthnew, imgwatermarkheightnew) , 0 , 0 , imgwatermarkwidth , imgwatermarkheight , graphicsunit.pixel , imageattributes ); imgphoto = bmwatermark; //以jpg格式保存图片 imgphoto.save(simgpath, system.drawing.imaging.imageformat.jpeg); //销毁对象 gbmphoto.dispose(); gwatermark.dispose(); imgphoto.dispose(); imgwatermark.dispose(); return true; } catch { return false ; } } /**//// <summary> /// 文字水印 /// </summary> /// <param name="imgfile">原图文件地址</param> /// <param name="textfont">水印文字</param> /// <param name="simgpath">文字水印图片保存地址</param> /// <param name="hscale">高度位置</param> /// <param name="widthfont">文字块在图片中所占宽度比例</param> /// <param name="alpha">文字透明度 其数值的范围在0到255</param> public bool zzstextwater( string imgfile , string textfont , string simgpath , float hscale , float widthfont , int alpha ) { try { filestream fs = new filestream(imgfile, filemode.open); binaryreader br = new binaryreader(fs); byte[] bytes = br.readbytes((int)fs.length); br.close(); fs.close(); memorystream ms = new memorystream(bytes); system.drawing.image imgphoto = system.drawing.image.fromstream(ms); //system.drawing.image imgphoto = system.drawing.image.fromfile(imgfile); int imgphotowidth = imgphoto.width; int imgphotoheight = imgphoto.height; bitmap bmphoto = new bitmap(imgphotowidth, imgphotoheight, system.drawing.imaging.pixelformat.format24bpprgb); bmphoto.setresolution(72, 72); graphics gbmphoto = graphics.fromimage(bmphoto); gbmphoto.interpolationmode = system.drawing.drawing2d.interpolationmode.high; gbmphoto.smoothingmode = system.drawing.drawing2d.smoothingmode.highquality; gbmphoto.drawimage( imgphoto , new rectangle(0, 0, imgphotowidth, imgphotoheight) , 0 , 0 , imgphotowidth , imgphotoheight , graphicsunit.pixel ); //建立字体大小的数组,循环找出适合图片的水印字体 //int[] sizes = new int[] { 1000, 800, 700, 650, 600, 560, 540, 500, 450, 400, 380, 360, 340, 320, 300, 280, 260, 240, 220, 200, 180, 160, 140, 120, 100, 80, 72, 64, 48, 32, 28, 26, 24, 20, 28, 16, 14, 12, 10, 8, 6, 4, 2 }; int[] sizes = new int[] { 28, 26, 24, 20, 16, 14, 12 }; system.drawing.font crfont = null; system.drawing.sizef crsize = new sizef(); for (int i = 0; i < 7; i++) { crfont = new font("微软雅黑", sizes[i], fontstyle.bold); crsize = gbmphoto.measurestring(textfont, crfont); if ((ushort)crsize.width < (ushort)imgphotowidth * widthfont) break; } //设置水印字体的位置 //int ypixlesfrombottom = (int)(imgphotoheight * hscale); //float yposfrombottom = ((imgphotoheight - ypixlesfrombottom) - (crsize.height / 2)); //float xcenterofimg = (imgphotowidth * 1 / 2); float yposfrombottom = imgphotoheight *0.85f; float xcenterofimg = imgphotowidth * 0.8f; //if (xcenterofimg<crsize.height) // xcenterofimg = (imgphotowidth * (1 - (crsize.height)/ imgphotowidth)); system.drawing.stringformat strformat = new system.drawing.stringformat(); strformat.alignment = system.drawing.stringalignment.center; // system.drawing.solidbrush semitransbrush2 = new system.drawing.solidbrush(color.fromargb(alpha, 0, 0, 0)); gbmphoto.drawstring( textfont , crfont , semitransbrush2 , new system.drawing.pointf(xcenterofimg + 1, yposfrombottom + 1) , strformat ); system.drawing.solidbrush semitransbrush = new system.drawing.solidbrush(color.fromargb(alpha, 255, 255, 255)); //gbmphoto.fillrectangle(semitransbrush2, new rectanglef(new pointf(xcenterofimg - crsize.width / 2, yposfrombottom - 4), crsize)); gbmphoto.drawstring( textfont , crfont , semitransbrush , new system.drawing.pointf(xcenterofimg, yposfrombottom) , strformat ); bmphoto.save(simgpath, system.drawing.imaging.imageformat.jpeg); gbmphoto.dispose(); imgphoto.dispose(); bmphoto.dispose(); return true; } catch { return false; } } /**//// <summary> /// 文字和logo图片水印 /// </summary> /// <param name="imgfile">原图文件地址</param> /// <param name="waterimg">水印图片地址</param> /// <param name="textfont">水印文字信息</param> /// <param name="simgpath">生存水印图片后的保存地址</param> /// <param name="imgalpha">水印图片的透明度</param> /// <param name="imgiscale">水印图片在原图上的显示比例</param> /// <param name="intimgdistance">水印图片在原图上的边距确定,以图片的右边和下边为准,当设定的边距超过一定大小后参数会自动失效</param> /// <param name="texthscale">水印文字高度位置,从图片底部开始计算,0-1</param> /// <param name="textwidthfont">文字块在图片中所占宽度比例 0-1</param> /// <param name="textalpha">文字透明度 其数值的范围在0到255</param> public void zzsimgtextwater( string imgfile , string waterimg , string textfont , string simgpath , float imgalpha , float imgiscale , int intimgdistance , float texthscale , float textwidthfont , int textalpha ) { try { filestream fs = new filestream(imgfile, filemode.open); binaryreader br = new binaryreader(fs); byte[] bytes = br.readbytes((int)fs.length); br.close(); fs.close(); memorystream ms = new memorystream(bytes); system.drawing.image imgphoto = system.drawing.image.fromstream(ms); //system.drawing.image imgphoto = system.drawing.image.fromfile(imgfile); int imgphotowidth = imgphoto.width; int imgphotoheight = imgphoto.height; bitmap bmphoto = new bitmap(imgphotowidth, imgphotoheight, system.drawing.imaging.pixelformat.format24bpprgb); bmphoto.setresolution(72, 72); graphics gbmphoto = graphics.fromimage(bmphoto); gbmphoto.interpolationmode = system.drawing.drawing2d.interpolationmode.high; gbmphoto.smoothingmode = system.drawing.drawing2d.smoothingmode.highquality; gbmphoto.drawimage( imgphoto , new rectangle(0, 0, imgphotowidth, imgphotoheight) , 0 , 0 , imgphotowidth , imgphotoheight , graphicsunit.pixel ); //建立字体大小的数组,循环找出适合图片的水印字体 int[] sizes = new int[] { 1000, 800, 700, 650, 600, 560, 540, 500, 450, 400, 380, 360, 340, 320, 300, 280, 260, 240, 220, 200, 180, 160, 140, 120, 100, 80, 72, 64, 48, 32, 28, 26, 24, 20, 28, 16, 14, 12, 10, 8, 6, 4, 2 }; system.drawing.font crfont = null; system.drawing.sizef crsize = new sizef(); for (int i = 0; i < 43; i++) { crfont = new font("arial", sizes[i], fontstyle.bold); crsize = gbmphoto.measurestring(textfont, crfont); if ((ushort)crsize.width < (ushort)imgphotowidth * textwidthfont) break; } //设置水印字体的位置 int ypixlesfrombottom = (int)(imgphotoheight * texthscale); float yposfrombottom = ((imgphotoheight - ypixlesfrombottom) - (crsize.height / 2)); float xcenterofimg = (imgphotowidth * 1 / 2); system.drawing.stringformat strformat = new system.drawing.stringformat(); strformat.alignment = system.drawing.stringalignment.center; // system.drawing.solidbrush semitransbrush2 = new system.drawing.solidbrush(color.fromargb(textalpha, 0, 0, 0)); gbmphoto.drawstring( textfont , crfont , semitransbrush2 , new system.drawing.pointf(xcenterofimg + 1, yposfrombottom + 1) , strformat ); system.drawing.solidbrush semitransbrush = new system.drawing.solidbrush(color.fromargb(textalpha, 255, 255, 255)); gbmphoto.drawstring( textfont , crfont , semitransbrush , new system.drawing.pointf(xcenterofimg, yposfrombottom) , strformat ); system.drawing.image imgwatermark = new bitmap(waterimg); int imgwatermarkwidth = imgwatermark.width; int imgwatermarkheight = imgwatermark.height; //计算水印图片尺寸 decimal ascale = convert.todecimal(imgiscale); decimal pscale = 0.05m; decimal minscale = ascale - pscale; decimal maxscale = ascale + pscale; int imgwatermarkwidthnew = imgwatermarkwidth; int imgwatermarkheightnew = imgwatermarkheight; if (imgphotowidth >= imgwatermarkwidth && imgphotoheight >= imgwatermarkheight && imgphotowidth >= imgphotoheight) if (imgwatermarkwidth > imgwatermarkheight) if ((minscale <= math.round((convert.todecimal(imgwatermarkwidth) / convert.todecimal(imgphotowidth)), 7)) && (math.round((convert.todecimal(imgwatermarkwidth) / convert.todecimal(imgphotowidth)), 7) <= maxscale)) { } else { imgwatermarkwidthnew = convert.toint32(imgphotowidth * ascale); imgwatermarkheightnew = convert.toint32((imgphotowidth * ascale / imgwatermarkwidth) * imgwatermarkheight); } else if ((minscale <= math.round((convert.todecimal(imgwatermarkheight) / convert.todecimal(imgphotoheight)), 7)) && (math.round((convert.todecimal(imgwatermarkheight) / convert.todecimal(imgphotoheight)), 7) <= maxscale)) { } else { imgwatermarkheightnew = convert.toint32(imgphotoheight * ascale); imgwatermarkwidthnew = convert.toint32((imgphotoheight * ascale / imgwatermarkheight) * imgwatermarkwidth); } if (imgwatermarkwidth >= imgphotowidth && imgwatermarkheight >= imgphotoheight && imgwatermarkwidth >= imgwatermarkheight) { imgwatermarkwidthnew = convert.toint32(imgphotowidth * ascale); imgwatermarkheightnew = convert.toint32(((imgphotowidth * ascale) / imgwatermarkwidth) * imgwatermarkheight); } if (imgwatermarkwidth >= imgphotowidth && imgwatermarkheight <= imgphotoheight && imgphotowidth >= imgphotoheight) { imgwatermarkwidthnew = convert.toint32(imgphotowidth * ascale); imgwatermarkheightnew = convert.toint32(((imgphotowidth * ascale) / imgwatermarkwidth) * imgwatermarkheight); } if (imgwatermarkwidth <= imgphotowidth && imgwatermarkheight >= imgphotoheight && imgphotowidth >= imgphotoheight) { imgwatermarkheightnew = convert.toint32(imgphotoheight * ascale); imgwatermarkwidthnew = convert.toint32(((imgphotoheight * ascale) / imgwatermarkheight) * imgwatermarkwidth); } if (imgphotowidth >= imgwatermarkwidth && imgphotoheight >= imgwatermarkheight && imgphotowidth <= imgphotoheight) if (imgwatermarkwidth > imgwatermarkheight) if ((minscale <= math.round((convert.todecimal(imgwatermarkwidth) / convert.todecimal(imgphotowidth)), 7)) && (math.round((convert.todecimal(imgwatermarkwidth) / convert.todecimal(imgphotowidth)), 7) <= maxscale)) { } else { imgwatermarkwidthnew = convert.toint32(imgphotowidth * ascale); imgwatermarkheightnew = convert.toint32(((imgphotowidth * ascale) / imgwatermarkwidth) * imgwatermarkheight); } else if ((minscale <= math.round((convert.todecimal(imgwatermarkheight) / convert.todecimal(imgphotoheight)), 7)) && (math.round((convert.todecimal(imgwatermarkheight) / convert.todecimal(imgphotoheight)), 7) <= maxscale)) { } else { imgwatermarkheightnew = convert.toint32(imgphotoheight * ascale); imgwatermarkwidthnew = convert.toint32(((imgphotoheight * ascale) / imgwatermarkheight) * imgwatermarkwidth); } if (imgwatermarkwidth >= imgphotowidth && imgwatermarkheight >= imgphotoheight && imgwatermarkwidth <= imgwatermarkheight) { imgwatermarkheightnew = convert.toint32(imgphotoheight * ascale); imgwatermarkwidthnew = convert.toint32(((imgphotoheight * ascale) / imgwatermarkheight) * imgwatermarkwidth); } if (imgwatermarkwidth >= imgphotowidth && imgwatermarkheight <= imgphotoheight && imgphotowidth <= imgphotoheight) { imgwatermarkwidthnew = convert.toint32(imgphotowidth * ascale); imgwatermarkheightnew = convert.toint32(((imgphotowidth * ascale) / imgwatermarkwidth) * imgwatermarkheight); } if (imgwatermarkwidth <= imgphotowidth && imgwatermarkheight >= imgphotoheight && imgphotowidth <= imgphotoheight) { imgwatermarkheightnew = convert.toint32(imgphotoheight * ascale); imgwatermarkwidthnew = convert.toint32(((imgphotoheight * ascale) / imgwatermarkheight) * imgwatermarkwidth); } //将原图画出来 bitmap bmwatermark = new bitmap(bmphoto); bmwatermark.setresolution(imgphoto.horizontalresolution, imgphoto.verticalresolution); graphics gwatermark = graphics.fromimage(bmwatermark); //指定高质量显示水印图片质量 gwatermark.interpolationmode = system.drawing.drawing2d.interpolationmode.high; gwatermark.smoothingmode = system.drawing.drawing2d.smoothingmode.highquality; system.drawing.imaging.imageattributes imageattributes = new system.drawing.imaging.imageattributes(); //设置两种颜色,达到合成效果 system.drawing.imaging.colormap colormap = new system.drawing.imaging.colormap(); colormap.oldcolor = color.fromargb(255, 0, 255, 0); colormap.newcolor = color.fromargb(0, 0, 0, 0); system.drawing.imaging.colormap[] remaptable = { colormap }; imageattributes.setremaptable(remaptable, system.drawing.imaging.coloradjusttype.bitmap); //用矩阵设置水印图片透明度 float[][] colormatrixelements = { new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f}, new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f}, new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f}, new float[] {0.0f, 0.0f, 0.0f, imgalpha, 0.0f}, new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f} }; system.drawing.imaging.colormatrix wmcolormatrix = new system.drawing.imaging.colormatrix(colormatrixelements); imageattributes.setcolormatrix(wmcolormatrix, system.drawing.imaging.colormatrixflag.default, system.drawing.imaging.coloradjusttype.bitmap); //确定水印边距 int xpos = imgphotowidth - imgwatermarkwidthnew; int ypos = imgphotoheight - imgwatermarkheightnew; int xposofwm = 0; int yposofwm = 0; if (xpos > intimgdistance) xposofwm = xpos - intimgdistance; else xposofwm = xpos; if (ypos > intimgdistance) yposofwm = ypos - intimgdistance; else yposofwm = ypos; gwatermark.drawimage( imgwatermark , new rectangle(xposofwm, yposofwm, imgwatermarkwidthnew, imgwatermarkheightnew) , 0 , 0 , imgwatermarkwidth , imgwatermarkheight , graphicsunit.pixel , imageattributes ); imgphoto = bmwatermark; //以jpg格式保存图片 imgphoto.save(simgpath, system.drawing.imaging.imageformat.jpeg); //销毁对象 gbmphoto.dispose(); gwatermark.dispose(); bmphoto.dispose(); imgphoto.dispose(); imgwatermark.dispose(); } catch { } } /**//// <summary> /// 缩略图 /// </summary> /// <param name="imgfile">原图文件地址</param> /// <param name="simgpath">缩略图保存地址</param> /// <param name="resizewidth">缩略图宽度</param> /// <param name="resizeheight">缩略图高度</param> /// <param name="bgcolor">缩略图背景颜色,注意,背景颜色只能指定knowncolor中的值,如blue,red,green等</param> public bool zzsresizeimg( string imgfile , string simgpath , int resizewidth , int resizeheight , string bgcolor ) { try { filestream fs = new filestream(imgfile, filemode.open); binaryreader br = new binaryreader(fs); byte[] bytes = br.readbytes((int)fs.length); br.close(); fs.close(); memorystream ms = new memorystream(bytes); system.drawing.image imgphoto = system.drawing.image.fromstream(ms); //system.drawing.image imgphoto = system.drawing.image.fromfile(imgfile); int imgphotowidth = imgphoto.width; int imgphotoheight = imgphoto.height; int startx = 0; int starty = 0; int newwidth = 0; int newheight = 0; if (imgphotowidth >= resizewidth && imgphotoheight >= resizeheight) { newwidth = resizewidth; newheight = convert.toint32(imgphotoheight * math.round(convert.todecimal(resizewidth) / convert.todecimal(imgphotowidth), 10)); startx = 0; starty = (resizeheight - newheight) / 2; } if (resizewidth > imgphotowidth && resizeheight < imgphotoheight) { newheight = resizeheight; newwidth = convert.toint32(imgphotowidth * math.round(convert.todecimal(resizeheight) / convert.todecimal(imgphotoheight), 10)); startx = (resizewidth - newwidth) / 2; starty = 0; } if (resizewidth < imgphotowidth && resizeheight > imgphotoheight) { newwidth = resizewidth; newheight = convert.toint32(imgphotoheight * math.round(convert.todecimal(resizewidth) / convert.todecimal(imgphotowidth), 10)); startx = 0; starty = (resizeheight - newheight) / 2; } if (imgphotowidth < resizewidth && imgphotoheight < resizeheight) { newwidth = imgphotowidth; newheight = imgphotoheight; startx = (resizewidth - imgphotowidth) / 2; starty = (resizeheight - imgphotoheight) / 2; } //计算缩放图片尺寸 bitmap bmphoto = new bitmap(resizewidth, resizeheight, system.drawing.imaging.pixelformat.format24bpprgb); bmphoto.setresolution(72, 72); graphics gbmphoto = graphics.fromimage(bmphoto); gbmphoto.clear(color.fromname(bgcolor)); gbmphoto.interpolationmode = system.drawing.drawing2d.interpolationmode.high; gbmphoto.smoothingmode = system.drawing.drawing2d.smoothingmode.highquality; gbmphoto.drawimage( imgphoto , new rectangle(startx, starty, newwidth, newheight) , new rectangle(0, 0, imgphotowidth, imgphotoheight) , graphicsunit.pixel ); bmphoto.save(simgpath, system.drawing.imaging.imageformat.jpeg); imgphoto.dispose(); gbmphoto.dispose(); bmphoto.dispose(); ms.close(); return true; } catch { return false; } } /**//// <summary> /// 图片剪切 /// </summary> /// <param name="imgfile">原图文件地址</param> /// <param name="simgpath">缩略图保存地址</param> /// <param name="pointx">剪切起始点 x坐标</param> /// <param name="pointy">剪切起始点 y坐标</param> /// <param name="cutwidth">剪切宽度</param> /// <param name="cutheight">剪切高度</param> public bool zzscutimg(string imgfile, string simgpath, int pointx, int pointy, int cutwidth, int cutheight) { filestream fs = new filestream(imgfile, filemode.open); binaryreader br = new binaryreader(fs); try { byte[] bytes = br.readbytes((int)fs.length); br.close(); fs.close(); memorystream ms = new memorystream(bytes); system.drawing.image imgphoto = system.drawing.image.fromstream(ms); //system.drawing.image imgphoto = system.drawing.image.fromfile(imgfile); //此处只能用filestream,用 system.drawing.image则会报多过进程访问文件的错误,会锁定文件 bitmap bmphoto = new bitmap(cutwidth, cutheight, system.drawing.imaging.pixelformat.format24bpprgb); bmphoto.setresolution(72, 72); graphics gbmphoto = graphics.fromimage(bmphoto); gbmphoto.interpolationmode = system.drawing.drawing2d.interpolationmode.high; gbmphoto.smoothingmode = system.drawing.drawing2d.smoothingmode.highquality; gbmphoto.drawimage( imgphoto , new rectangle(0, 0, cutwidth, cutheight) , new rectangle(pointx, pointy, cutheight, cutheight) , graphicsunit.pixel ); bmphoto.save(simgpath, system.drawing.imaging.imageformat.jpeg); imgphoto.dispose(); gbmphoto.dispose(); bmphoto.dispose(); ms.close(); return true; } catch { return false; } finally { } } }
希望本文所述对大家c#程序设计有所帮助。