This time I will show you how to use JS to drag and drop files to upload, and what are the precautions to use JS to drag and drop files to upload. The following is a practical case, let's take a look.
<!doctype html> <html> <head> <meta charset="utf-8"> <title>JS文件拖拽上传</title> <style> p{ width: 300px; height: 300px; border:1px dashed #000; position:absolute; top: 50%; left: 50%; margin:-150px 0 0 -150px; text-align:center; font:20px/300px '微软雅黑'; display:none; } </style> <script> window.onload = function () { var oBox = document.getElementById('box'); var oM = document.getElementById('m1'); var timer = null; document.ondragover = function(){ clearTimeout(timer); timer = setTimeout(function(){ oBox.style.display = 'none'; },200); oBox.style.display = 'block'; }; //进入子集的时候 会触发ondragover 频繁触发 不给ondrop机会 oBox.ondragenter = function(){ oBox.innerHTML = '请释放鼠标'; }; oBox.ondragover = function(){ return false; }; oBox.ondragleave = function(){ oBox.innerHTML = '请将文件拖拽到此区域'; }; oBox.ondrop = function(ev){ var oFile = ev.dataTransfer.files[0]; var reader = new FileReader(); //读取成功 reader.onload = function(){ console.log(reader); }; reader.onloadstart = function(){ alert('读取开始'); }; reader.onloadend = function(){ alert('读取结束'); }; reader.onabort = function(){ alert('中断'); }; reader.onerror = function(){ alert('读取失败'); }; reader.onprogress = function(ev){ var scale = ev.loaded/ev.total; if(scale>=0.5){ alert(1); reader.abort(); } oM.value = scale*100; }; reader.readAsDataURL(oFile,'base64'); return false; }; }; </script> </head> <body> <meter id="m1" value="0" min="0" max="100"></meter> <p id="box">请将文件拖拽到此区域</p> </body> </html>
How to use Vue to integrate AdminLTE template
How to use JS to make a Tic-Tac-Toe game
The above is the detailed content of How to use JS to drag and drop files to upload. For more information, please follow other related articles on the PHP Chinese website!