clipboardData 在网页中实现截屏粘贴的功能

<script type="text/javascript">
(function(){
    var imgReader = function( item ){
        var blob = item.getAsFile(),
            reader = new FileReader();
           
        reader.onload = function( e ){
            var img = new Image();
           
            img.src = e.target.result;
            document.body.appendChild( img );
        };
       
        reader.readAsDataURL( blob );
    };

    document.getElementById( 'testInput' ).addEventListener( 'paste', function( e ){
    var clipboardData = e.clipboardData,
        i = 0,
        items, item, types;
       
    if( clipboardData ){
        items = clipboardData.items;
       
        if( !items ){
            return;
        }
       
        item = items[0];
        types = clipboardData.types || [];
       
        for( ; i < types.length; i++ ){
            if( types[i] === 'Files' ){
                item = items[i];
                break;
            }
        }
       
        if( item && item.kind === 'file' && item.type.match(/^image//i) ){
            imgReader( item );
        }
    }
    });
})(); 
</script>
   
</body>
</html>