防止拖拽文本域

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>防止拖拽文本域</title>
<style>
textarea {
width: 500px;
height: 249px;
/*取消轮廓线*/
outline: none;
/*边框改变颜色*/
border: 1px solid #036;
/*防止用户拖拽文本域*/
resize: none;
}
</style>
</head>
<body>
<textarea>请留了言</textarea>
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</body>
</html>