jquery实现图片上传前的预览

html代码

<div id="uploadPreview"></div>
<input id="uploadImage" type="file" name="photoimage" class="fimg1" onchange="PreviewImage();" />

js代码

$("#uploadImage").on("change", function(){
    // Get a reference to the fileList
    var files = !!this.files ? this.files : [];

    // If no files were selected, or no FileReader support, return
    if (!files.length || !window.FileReader) return;

    // Only proceed if the selected file is an image
    if (/^image/.test( files[0].type)){

        // Create a new instance of the FileReader
        var reader = new FileReader();

        // Read the local file as a DataURL
        reader.readAsDataURL(files[0]);

        // When loaded, set image data as background of div
        reader.onloadend = function(){

       $("#uploadPreview").css("background-image", "url("+this.result+")");

        }

    }

});