Javascript/jQuery 图像缩放插件

Question

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Answer 1

由于这个问题现在已经被看到超过 1k 次，所以我将我的解决方案添加到其中。随意复制和改编。

解决方案涉及 jQuery UI slider 插件。主要是我们创建一个固定大小的div，overflow:scroll，里面有一个img标签，我们在下面添加一个slider。 slider “更改”事件绑定(bind)到 img@width/@height 属性的重新缩放。

这是我们所做的摘录:

HTML

    <div id="pictureFilePreview">
        <img id="pictureFilePreviewImg" src="style/images/spacer.gif"/>
    </div>
    <div id="pictureSlider"/>

JS

$('#pictureFilePreview').css('overflow','scroll');
$('#pictureFilePreviewImg')
    .attr("src", "http://url.of.the.image")
    .css("display","block")
    .bind("load", function(){ //wait for complete load of the image
        // Slider  
        var initHeight = parseInt($('#pictureFilePreviewImg').attr("height"));  
        var initWidth = parseInt($('#pictureFilePreviewImg').attr("width"));  
        if ($('#pictureFilePreview').width() < initWidth 
            || $('#pictureFilePreview').height() < initHeight) {                

            var deltaW = $('#pictureFilePreview').width() - initWidth;  
            var deltaH = $('#pictureFilePreview').height() - initHeight;
            var ratio = 0;
            if (deltaW < deltaH) {
                ratio = ($('#pictureFilePreview').width() / initWidth) * 100;
            } else {
                ratio = ($('#pictureFilePreview').height() / initHeight) * 100;
            }
            $('#pictureSlider').slider({  
                range: false,
                min : ratio,
                values: [100],
                change: function(event, ui) {  
                    var newHeight = ((initHeight) * ui.value / 100);  
                    var newWidth = ((initWidth) * ui.value / 100); 
                    $('#pictureFilePreviewImg').attr("height",newHeight);  
                    $('#pictureFilePreviewImg').attr("width",newWidth);  
                    $('#pictureFilePreview').css('overflow',ui.value === 0?'visible':'scroll');  
                }  
            }); 
        }
    });