<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <title>Document</title></head><body> <canvas id="canvas" style="margin:0 auto;border:1px #ddd solid"> The current browser does not support Canvas, can replace the browser a try! </canvas> <script> window.onload = function(){ var canvas = document.getElementById('canvas'); canvas.width = 1024; canvas.height = 768; if(canvas.getContext('2d')){ var context = canvas.getContext('2d'); context.fillStyle = "blue"; context.fillRect(100,200,400,400); context.globalCompositeOperation = "sourse-over"; context.fillStyle = "red"; context.beginPath(); context.moveTo(400,300); context.lineTo(650,700); context.lineTo(150,700); context.closePath(); context.fill(); }else{ alert('當(dāng)前游覽器不支持Canvas,請(qǐng)更換游覽器后再試!'); } } </script></body><script> /*global globalAlpha globalCompositeOperation = "source-over"(default) sourse-atop sourse-in sourse-out destination-over //前面繪制的覆蓋了后面繪制的圖形 destination-atop destination-in destination-out lighter copy xor */</script></html>
新聞熱點(diǎn)
疑難解答
圖片精選