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利用canvas和localstorage实现本地存储图片

利用canvas和localstorage实现本地存储图片

作者: 安石0 | 来源:发表于2018-01-24 23:00 被阅读0次
//转载
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
          <input id="haorooms_btn" type="button" value="图片显示">
    <div id="haorooms_div"></div>

        <script type="text/javascript">
            function test(){
                window.open('a.html?init=first')
            }
            function saveImg( key ){
   var img = new Image,
    canvas = document.createElement("canvas"),
    ctx = canvas.getContext("2d"),
    src='./timg.jpg'
    img.crossOrigin = "Anonymous";

    img.onload = function() {
        canvas.width = img.width;
        canvas.height = img.height;
        ctx.drawImage( img, 0, 0 );
        localStorage.setItem( key, canvas.toDataURL("image/png") );
    }
    img.src = src;
    // make sure the load event fires for cached images too
    if ( img.complete || img.complete === undefined ) {
        img.src = "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw==";
        img.src = src;
    }
 }
    function get(div,key){//读取get(容器,图片)
    var srcStr = localStorage.getItem(key);
    var imgObj = document.createElement('img');
    imgObj.src = srcStr;
    div.appendChild(imgObj);
}
    window.onload = function(){
        if(! localStorage.getItem('savedImageData')){
            saveImg("savedImageData");
        }
    
    var haoroomsbtn = document.getElementById('haorooms_btn');
    var oDiv = document.getElementById('haorooms_div');
    haoroomsbtn.onclick = function(){
        get(oDiv,"savedImageData");
    }
}  
    </script>
    </body>
</html>

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