1.如何禁用頁面元素拖出去
οndragstart="return false;" //禁止鼠標拖動，如拖動圖片、連接等
例如：
<body οndragstart="return false;" οncοntextmenu="return false;">
2.如何禁用拖元素進入頁面
<script>
document.ondrop = function(event) {
return false;
};
document.ondragenter = function(event) {
return false;
};
document.ondragover = function(event) {
return false;
};
</script>
參考資料：
https://blog.csdn.net/OrangeJuiceMe/article/details/64125068
https://cloud.tencent.com/developer/article/1476542