js 制作电子印章
圆形章
<!DOCTYPE HTML> <HEAD> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>圆形公章</title> </HEAD> <body> <BR> 输入单位（14位，多了自己调）：<input id="dw" width="50" type="text" value='某某某某某某某某某单位人事部'/> <br> 输入单位(英文)：<input id="edw" width="50" type="text" value='WTYRBCHFBBDHCBFVBDDD'/> <br> 章下面文字：<input id="mdtext" width="50" type="text" value='专用章'/> <div id="sealdiv" > <canvas id="canvas" width="250" height="250"></canvas> </div> <input type="button" onclick="javascript:createSealEx();" value="生成中英公章"/> <input type="button" onclick="javascript:createSealEx2();" value="生成中公章"/> </body> <SCRIPT LANGUAGE="javascript"> function createSealEx(){ var dw = document.getElementById("dw"); var edw = document.getElementById("edw"); var mdtext = document.getElementById("mdtext"); var tuzhangdiv = document.getElementById("tuzhangdiv"); tuzhangdiv.innerHTML ="<canvas id='canvas' width='160' height='160'></canvas>"; createSeal('canvas',dw.value,edw.value,mdtext.value); } function createSealEx2(){ var dw = document.getElementById("dw"); var edw = document.getElementById("edw"); var mdtext = document.getElementById("mdtext"); var tuzhangdiv = document.getElementById("tuzhangdiv"); tuzhangdiv.innerHTML ="<canvas id='canvas' width='160' height='160'></canvas>"; createSeal11('canvas',dw.value,mdtext.value); } function createSeal11(id,company,name){ var canvas = document.getElementById(id); var context = canvas.getContext('2d'); // 绘制印章边框 var width=canvas.width/2; var height=canvas.height/2; context.lineWidth=2; context.strokeStyle="#f00"; context.beginPath(); context.arc(width,height,78,0,Math.PI*2); context.stroke(); context.save(); context.lineWidth=1; context.strokeStyle="#f00"; context.beginPath(); context.arc(width,height,75,0,Math.PI*2); context.stroke(); context.save(); //画五角星 create5star(context,width,height,25,"#f00",0); // 绘制印章名称 context.font = '18px Helvetica'; context.textBaseline = 'middle';//设置文本的垂直对齐方式 context.textAlign = 'center'; //设置文本的水平对对齐方式 context.lineWidth=1; context.fillStyle = '#f00'; context.fillText(name,width,height+53); // 绘制印章单位 context.translate(width,height);// 平移到此位置, context.font = '20px Helvetica' var count = company.length;// 字数 var angle = 4*Math.PI/(3*(count - 1));// 字间角度 var chars = company.split(""); var c; for (var i = 0; i < count; i++){ c = chars[i];// 需要绘制的字符 if(i==0) context.rotate(5*Math.PI/6); else context.rotate(angle); context.save(); context.translate(64, 0);// 平移到此位置,此时字和x轴垂直 context.rotate(Math.PI/2);// 旋转90度,让字平行于x轴 context.fillText(c,0, 5);// 此点为字的中心点 context.restore(); } } function createSeal(id,company,ecompany,name){ var canvas = document.getElementById(id); var context = canvas.getContext('2d'); context.translate(0,0);//移动坐标原点 // 绘制印章边框 var width=canvas.width/2; var height=canvas.height/2; //边框1 context.lineWidth=2; context.strokeStyle="#f00"; context.beginPath(); context.arc(width,height,78,0,Math.PI*2); context.stroke(); context.save(); //边框2 context.lineWidth=1; context.strokeStyle="#f00"; context.beginPath(); context.arc(width,height,63,0,Math.PI*2); context.stroke(); context.save(); //画五角星 create5star(context,width,height,20,"#f00",0); // 绘制印章类型 context.font = 'bolder 15px SimSun'; context.textBaseline = 'middle';//设置文本的垂直对齐方式 context.textAlign = 'center'; //设置文本的水平对对齐方式 context.lineWidth=1; context.fillStyle = '#f00'; context.fillText(name,width,height+50); // 绘制印章中文单位 context.translate(width,height);// 平移到此位置, context.font = 'bolder 18px SimSun' var count = company.length;// 字数 var angle = 4*Math.PI/(3*(count-1));// 字间角度 var chars = company.split(""); var c; for (var i = 0; i < count; i++){ c = chars[i];// 需要绘制的字符 if(i==0) context.rotate(5*Math.PI/6); else context.rotate(angle); context.save(); // 平移到此位置,此时字和x轴垂直，第一个参数是与圆外边的距离，越大距离越近 context.translate(52, 0); context.rotate(Math.PI/2);// 旋转90度,让字平行于x轴 context.fillText(c,0, 5);// 此点为字的中心点 context.restore(); } //绘制印章英文单位 context.translate(width-80,height-80);// 平移到此位置, context.font = 'bolder 10px SimSun'; var ecount = ecompany.length;// 字数 var eangle = (5*Math.PI)/(3*(ecount));// 字间角度 var echars = ecompany.split(""); var ec; for (var j = 0; j < ecount; j++){ ec = echars[j];// 需要绘制的字符 if(j==0) context.rotate(6*Math.PI/7-1); else context.rotate(eangle); context.save(); // 平移到此位置,此时字和x轴垂直，第一个参数是与圆外边的距离，越大距离越近 context.translate(74, 0); context.rotate(Math.PI/2);// 旋转90度,让字平行于x轴 context.fillText(ec,0, 4.8);// 此点为字的中心点 context.restore(); } } //绘制五角星 function create5star(context,sx,sy,radius,color,rotato){ context.save(); context.fillStyle=color; context.translate(sx,sy);//移动坐标原点 context.rotate(Math.PI+rotato);//旋转 context.beginPath();//创建路径 var x = Math.sin(0); var y= Math.cos(0); var dig = Math.PI/5 *4; for(var i = 0;i< 5;i++){//画五角星的五条边 var x = Math.sin(i*dig); var y = Math.cos(i*dig); context.lineTo(x*radius,y*radius); } context.closePath(); context.stroke(); context.fill(); context.restore(); } </html>
椭圆章
<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>椭圆</title> </head> <body> 输入单位（支持最多14位，多了自己调）：<input id="dw" width="50" type="text" value='测试印章椭圆科技有限公司公司'/> <br> 输入单位(英文)：<input id="edw" width="50" type="text" value='EASTPORTCOMPANY'/> <br> 章下面文字：<input id="mdtext" width="50" type="text" value='公司章'/> <div id="sealdiv" > <canvas id="canvas" width="165" height="165"></canvas> </div> </div> <input type="button" onclick="javascript:createSealEx();" value="生成中文公章"/> <input type="button" onclick="javascript:createSealEx2();" value="生成中英公章"/> <script> function createSealEx(){ var dw = document.getElementById("dw"); var edw = document.getElementById("edw"); var mdtext = document.getElementById("mdtext"); var sealdiv = document.getElementById("sealdiv"); sealdiv.innerHTML ="<canvas id='canvas' width='165' height='165'></canvas>"; createSeal2('canvas',dw.value,mdtext.value); } function createSealEx2(){ var dw = document.getElementById("dw"); var edw = document.getElementById("edw"); var mdtext = document.getElementById("mdtext"); var sealdiv = document.getElementById("sealdiv"); sealdiv.innerHTML ="<canvas id='canvas' width='165' height='165'></canvas>"; createSeal1('canvas',dw.value,edw.value,mdtext.value); } function createSeal1(id,company,ecompany,name){ var canvas = document.getElementById("canvas"); var context = canvas.getContext("2d"); context.strokeStyle="red";//设置边框颜色 context.textBaseline = 'middle';//设置文本的垂直对齐方式 context.textAlign = 'center'; //设置文本的水平对对齐方式 context.lineWidth = 2;//椭圆1宽度 //3个参数： 左边距 上边据 宽度 椭圆扁度 BezierEllipse4(context, 85, 79, 79, 55); //椭圆1 context.lineWidth = 1; BezierEllipse4(context, 85, 79, 76, 52); //椭圆2 context.lineWidth = 2; BezierEllipse4(context, 85, 79, 63, 39); //椭圆3 // 绘制印章类型 context.font = 'bolder 10px SimSun';//设置字体大小 样式 context.fillStyle = 'red';//设置字体颜色 context.fillText(name,canvas.width/2+3,canvas.height/2+25); context.save(); //保存上述操作 //绘制英文 var circle={ x:canvas.width/2, y:canvas.height/2, radius:58 }; var startAngle=220;//控制字符起始位置度数 var endAngle =-40;//首位字符相隔度数 var radius=circle.radius //圆的半径 var angleDecrement=(startAngle-endAngle)/(ecompany.length-1)//每个字母占的弧度 context.font="bolder 10px SimSun" context.lineWidth=1;//设置字体胖瘦 var ratioX = 70 / circle.radius; //横轴缩放比率 var ratioY = 45 / circle.radius; //纵轴缩放比率 //进行缩放（均匀压缩） 重点 context.scale(ratioX, ratioY); var index=0; for(var index=0;index<ecompany.length;index++){ //保存之前的设置开始绘画 context.save(); context.beginPath(); context.translate(circle.x+Math.cos((Math.PI/180)*startAngle)*radius-12,circle.y-Math.sin((Math.PI/180)*startAngle)*radius+19)//绘制点 +-微调 context.rotate((Math.PI/2)-(Math.PI/180)*startAngle) ; //Math.PI/2为旋转90度 Math.PI/180*X为旋转多少度 context.fillText(ecompany.charAt(index),0,0); context.strokeText(ecompany.charAt(index),0,0); startAngle-=angleDecrement; context.restore(); } // 绘制印章类型 context.font = 'bolder 14px SimSun'; context.lineWidth=1; context.fillStyle = '#f00'; context.fillText(company.substring(0,6),canvas.width/2-11,canvas.height/2+6); context.save(); context.font = 'bolder 14px SimSun'; context.lineWidth=1; context.fillStyle = '#f00'; context.fillText(company.substring(6,12),canvas.width/2-12,canvas.height/2+25); context.save(); context.font = 'bolder 14px SimSun'; context.lineWidth=1; context.fillStyle = '#f00'; context.fillText(company.substring(12,company.length),canvas.width/2-12,canvas.height/2+40); context.save(); } function createSeal2(id,company,name){ var canvas = document.getElementById("canvas"); var context = canvas.getContext("2d"); context.strokeStyle="red";//设置文本颜色 context.textBaseline = 'middle';//设置文本的垂直对齐方式 context.textAlign = 'center'; //设置文本的水平对对齐方式 context.lineWidth = 2;//椭圆1宽度 //3个参数： 左边距 上边据 宽度 椭圆扁度 BezierEllipse4(context, 85, 79, 79, 55); //椭圆1 context.lineWidth = 1; BezierEllipse4(context, 85, 79, 76, 52); //椭圆2 // 绘制印章类型 context.font = 'bolder 15px SimSun'; context.lineWidth=1; context.fillStyle = '#f00'; context.fillText(name,canvas.width/2+3,canvas.height/2+10); context.save(); //绘制中文 var ccircle={ x:canvas.width/2, y:canvas.height/2, radius:59 }; var cstartAngle=170;//控制字符起始位置度数 var cendAngle =15;//首位字符相隔度数 var cradius=ccircle.radius //圆的半径 var cangleDecrement=(cstartAngle-cendAngle)/(company.length-1)//每个字母占的弧度 context.font="12px SimSun" var cratioX = 66 / ccircle.radius; //横轴缩放比率 var cratioY = 57 / ccircle.radius; //纵轴缩放比率 //进行缩放（均匀压缩） context.scale(cratioX, cratioY); var cindex=0; for(var cindex=0;cindex<company.length;cindex++){ context.save() context.beginPath() //绘制点 context.translate(ccircle.x+Math.cos((Math.PI/180)*cstartAngle)*cradius-6,ccircle.y-Math.sin((Math.PI/180)*cstartAngle)*cradius+14) context.rotate((Math.PI/2)-(Math.PI/180)*cstartAngle) //Math.PI/2为旋转90度 Math.PI/180*X为旋转多少度 context.fillText(company.charAt(cindex),0,0) context.strokeText(company.charAt(cindex),0,0) cstartAngle-=cangleDecrement context.restore() } } function BezierEllipse4(ctx, x, y, a, b){ var k = .5522848, ox = a * k, // 水平控制点偏移量 oy = b * k; // 垂直控制点偏移量</p> <p> ctx.beginPath(); //从椭圆的左端点开始顺时针绘制四条三次贝塞尔曲线 ctx.moveTo(x - a, y); ctx.bezierCurveTo(x - a, y - oy, x - ox, y - b, x, y - b); ctx.bezierCurveTo(x + ox, y - b, x + a, y - oy, x + a, y); ctx.bezierCurveTo(x + a, y + oy, x + ox, y + b, x, y + b); ctx.bezierCurveTo(x - ox, y + b, x - a, y + oy, x - a, y); ctx.closePath(); ctx.stroke(); }; </script> </body> </html>
以上是点击生成电子印章，如果想要页面加载时直接显示就把点击方法里的事件写入onload里；
例如：
window.onload = function () { var dw = document.getElementById("dw"); var edw = document.getElementById("edw"); var mdtext = document.getElementById("mdtext"); var tuzhangdiv = document.getElementById("tuzhangdiv"); tuzhangdiv.innerHTML = "<canvas id='canvas' width='360' height='360'></canvas>"; createSeal11('canvas', dw.value, mdtext.value); //createSeal11('canvas', "上海**科技股份有限公司", ""); }
转载与：https://blog.csdn.net/qq_26721093/article/details/129219953
