Click upload pictures, show preview (single image)

js code

 

 

// When the value of the element of change, change events occur.

$ ( "# Upload button id"). Change (function () {

　　var reads = new FileReader();

　　var f = document.getElementById ( "upload button id") files [0].;

　　reads.readAsDataURL(f);

　　reads.onload = function(){

　　　　document.getElementById ( "id you want to display a large picture img tag") src = this.result.;

　　}

)

 

Note: Some native js code above to obtain elements can not operate normally after the acquisition method of jquery replaced; code I do not quite understand the specific meaning, welcome to share