本文实例为大家分享了html5 canvas在图片上画超链接的具体代码,供大家参考,具体内容如下
1. html
<canvas id="canvasfile" style="margin-top:15px;" width="500" height="400"></canvas> <input type="button" id="btnredo" value="re-draw" class="btn btn-warning"/>
2. javascript
var photow = 400; var photoh = 300; var photo; // logic load image into canvas // ... // e.g. // photo = new image(); // photo.onload = function() { // draw photo into canvas when ready // ctx.drawimage(photo, 0, 0, photow, photoh); // }; // load photo into canvas // photo.src = picurl; // canvas highlight var canvas = document.getelementbyid('canvasfile'), ctx = canvas.getcontext('2d'), img = new image; var btndone = document.getelementbyid('btndone'); var btnredo = document.getelementbyid('btnredo'); ctx.strokestyle = '#ff0000'; function drawdot(x, y) { var centerx = x; var centery = y; var radius = 2; ctx.beginpath(); ctx.arc(centerx, centery, radius, 0, 2 * math.pi, false); ctx.fillstyle = 'red'; ctx.fill(); ctx.linewidth = 2; ctx.strokestyle = '#ff0000'; ctx.stroke(); } function startdrawing() { ctx.drawimage(img, 0, 0, photow, photoh); canvas.onmousemove = mousemoving; canvas.onmousedown = mousedownhandle; canvas.onmouseup = mouseuphandle; // ## mobile events //touchstart – to toggle drawing mode “on” //touchend – to toggle drawing mode “off” //touchmove – to track finger position, used in drawing canvas.addeventlistener('touchmove', touchmove, false); canvas.addeventlistener('touchend', mouseuphandle, false); btnredo.onclick = function (e) { ctx.clearrect(0, 0, ctx.width, ctx.height); ctx.drawimage(photo, 0, 0, photow, photoh); savedrawing(); } } function savedrawing(e) { var image = document.getelementbyid('canvasfile').todataurl("image/jpeg"); image = image.replace('data:image/jpeg;base64,', ''); $("#imgnric1").val(image); }; function mousemoving(e) { if (drawing) { mousedownhandle(e); } } var drawing = false; function mousedownhandle(e) { drawing = true; var r = canvas.getboundingclientrect(), x = e.clientx - r.left, y = e.clienty - r.top; drawdot(x, y); } function mouseuphandle(e) { savedrawing(); e.preventdefault(); drawing = false; } //// mobile touch events function touchmove(e) { if (e.clientx > 800) { mousedownhandle(e); return; } var r = canvas.getboundingclientrect(), //event.changedtouches[0].pagex + ":" + event.changedtouches[0].pagey; x = e.changedtouches[0].pagex - r.left, y = e.changedtouches[0].pagey - r.top; drawdot(x, y); e.preventdefault(); }
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持移动技术网。
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