在画布中打开本地图像 [英] Open local image in canvas
本文介绍了在画布中打开本地图像的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在尝试制作一个javascript图像颜色选择器。
可以在画布上打开本地图片,而不需要上传到服务器?
function draw(){
var ctx = document.getElementById('canvas')。getContext('2d');
var img = new Image();
img.onload = function(){
ctx.drawImage(img,0,0);
}
img.src = $('#uploadimage')。val();
}
< input type ='file'name ='img'size = '65'id ='uploadimage'/>
解决方案
不支持所有浏览器(IE和Opera AFAIK)但您可以使用 File API 获取数据URI
函数draw(){
var ctx = document.getElementById('canvas')。getContext('2d')
,img = new Image()
,f = document.getElementById(uploadimage)。files [0]
,url = window.URL || window.webkitURL
,src = url.createObjectURL(f);
img.src = src;
img.onload = function(){
ctx.drawImage(img,0,0);
url.revokeObjectURL(src);
}
}
< input type ='file'name ='img'size = '65'id ='uploadimage'/>
我添加了小提琴这里。
i'm trying to make an javascript image color picker. It is possible to open local image in canvas, without uploading it to server ?
function draw() {
var ctx = document.getElementById('canvas').getContext('2d');
var img = new Image();
img.onload = function(){
ctx.drawImage(img,0,0);
}
img.src = $('#uploadimage').val();
}
<input type='file' name='img' size='65' id='uploadimage' />
解决方案
Not supported in all browser (IE and Opera AFAIK) but you could get a data URI using the File API
function draw() {
var ctx = document.getElementById('canvas').getContext('2d')
, img = new Image()
, f = document.getElementById("uploadimage").files[0]
, url = window.URL || window.webkitURL
, src = url.createObjectURL(f);
img.src = src;
img.onload = function(){
ctx.drawImage(img,0,0);
url.revokeObjectURL(src);
}
}
<input type='file' name='img' size='65' id='uploadimage' />
I added a fiddle here as an example.
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