站長資訊網(wǎng)下面分享一個(gè)用HTML5 Canvas畫印章效果實(shí)例代碼，可以看一下
<!DOCTYPE html> <html> <head> <meta charset="gbk"> <title>HTML5 Canvas畫印章</title> </head> <body> <canvas id="canvas" width="200" height="200"></canvas> <script> var canvas = document.getElementById("canvas"); var context = canvas.getContext('2d'); var text = "XXX專用章"; var companyName = "浙江網(wǎng)絡(luò)科技股份有限公司"; // 繪制印章邊框 var width = canvas.width / 2; var height = canvas.height / 2; context.lineWidth = 5; context.strokeStyle = "#f00"; context.beginPath(); context.arc(width, height, 90, 0, Math.PI * 2);//寬、高、半徑 context.stroke(); //畫五角星 create5star(context,width,height,25,"#f00",0); // 繪制印章名稱 context.font = '20px 宋體'; context.textBaseline = 'middle';//設(shè)置文本的垂直對齊方式 context.textAlign = 'center'; //設(shè)置文本的水平對對齊方式 context.lineWidth=1; context.strokeStyle = '#f00'; context.strokeText(text,width,height+60); // 繪制印章單位 context.translate(width,height);// 平移到此位置, context.font = '23px 宋體' var count = companyName.length;// 字?jǐn)?shù) var angle = 4*Math.PI/(3*(count - 1));// 字間角度 var chars = companyName.split(""); var c; for (var i = 0; i < count; i++) { c = chars[i];// 需要繪制的字符 if (i == 0) { context.rotate(5 * Math.PI / 6); } else{ context.rotate(angle); } context.save(); context.translate(70, 0);// 平移到此位置,此時(shí)字和x軸垂直，公司名稱和最外圈的距離 context.rotate(Math.PI / 2);// 旋轉(zhuǎn)90度,讓字平行于x軸 context.strokeText(c, 0, 0);// 此點(diǎn)為字的中心點(diǎn) context.restore(); } //繪制五角星 /** * 創(chuàng)建一個(gè)五角星形狀. 該五角星的中心坐標(biāo)為(sx,sy),中心到頂點(diǎn)的距離為radius,rotate=0時(shí)一個(gè)頂點(diǎn)在對稱軸上 * rotate:繞對稱軸旋轉(zhuǎn)rotate弧度 */ function create5star(context, sx, sy, radius, color, rotato) { context.save(); context.fillStyle = color; context.translate(sx, sy);//移動(dòng)坐標(biāo)原點(diǎn) context.rotate(Math.PI + rotato);//旋轉(zhuǎn) context.beginPath();//創(chuàng)建路徑 var x = Math.sin(0); var y = Math.cos(0); var dig = Math.PI / 5 * 4; for (var i = 0; i < 5; i++) {//畫五角星的五條邊 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(); } </script>
<!DOCTYPE html> <html> <head> <meta charset="gbk"> <title>HTML5 Canvas畫印章</title> </head> <body> <canvas id="canvas" width="200" height="200"></canvas> <script> var canvas = document.getElementById("canvas"); var context = canvas.getContext('2d'); var text = "XXX專用章"; var companyName = "浙江網(wǎng)絡(luò)科技股份有限公司"; // 繪制印章邊框 var width = canvas.width / 2; var height = canvas.height / 2; context.lineWidth = 5; context.strokeStyle = "#f00"; context.beginPath(); context.arc(width, height, 90, 0, Math.PI * 2);//寬、高、半徑 context.stroke(); //畫五角星 create5star(context,width,height,25,"#f00",0); // 繪制印章名稱 context.font = '20px 宋體'; context.textBaseline = 'middle';//設(shè)置文本的垂直對齊方式 context.textAlign = 'center'; //設(shè)置文本的水平對對齊方式 context.lineWidth=1; context.strokeStyle = '#f00'; context.strokeText(text,width,height+60); // 繪制印章單位 context.translate(width,height);// 平移到此位置, context.font = '23px 宋體' var count = companyName.length;// 字?jǐn)?shù) var angle = 4*Math.PI/(3*(count - 1));// 字間角度 var chars = companyName.split(""); var c; for (var i = 0; i < count; i++) { c = chars[i];// 需要繪制的字符 if (i == 0) { context.rotate(5 * Math.PI / 6); } else{ context.rotate(angle); } context.save(); context.translate(70, 0);// 平移到此位置,此時(shí)字和x軸垂直，公司名稱和最外圈的距離 context.rotate(Math.PI / 2);// 旋轉(zhuǎn)90度,讓字平行于x軸 context.strokeText(c, 0, 0);// 此點(diǎn)為字的中心點(diǎn) context.restore(); } //繪制五角星 /** * 創(chuàng)建一個(gè)五角星形狀. 該五角星的中心坐標(biāo)為(sx,sy),中心到頂點(diǎn)的距離為radius,rotate=0時(shí)一個(gè)頂點(diǎn)在對稱軸上 * rotate:繞對稱軸旋轉(zhuǎn)rotate弧度 */ function create5star(context, sx, sy, radius, color, rotato) { context.save(); context.fillStyle = color; context.translate(sx, sy);//移動(dòng)坐標(biāo)原點(diǎn) context.rotate(Math.PI + rotato);//旋轉(zhuǎn) context.beginPath();//創(chuàng)建路徑 var x = Math.sin(0); var y = Math.cos(0); var dig = Math.PI / 5 * 4; for (var i = 0; i < 5; i++) {//畫五角星的五條邊 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(); } </script>
