js前端驗證上傳的文件大小及格式

js前端驗證上傳的文件大小及格式
<script type="text/javascript">
        function fileChange(target) {
            var fileSize = 0;
            if (!target.files) {
                var filePath = target.value;
                var fileSystem = new ActiveXObject("Scripting.FileSystemObject");
                var file = fileSystem.GetFile(filePath);
                fileSize = file.Size;
            } else {
                fileSize = target.files[0].size;
            }

            var size = fileSize / 1024;
            if (size <110) { //空白的Excel表最大為10.1KB，當小於它及判斷為Excel內容為空
                alert("導入的Excel表不能為空！");
                target.value = "";
                return
            } 
            if (size > 5000) {
                alert("導入的Excel表不能大於5M！");
                target.value = "";
                return
            }            
            var name = target.value;
            var fileName = name.substring(name.lastIndexOf(".") + 1).toLowerCase();
            if (fileName != "xlsx" && fileName != "xls") {
                alert("請選擇.xlsx格式文件上傳！");
                target.value = "";
                return
            }
        } 
    </script>

 

調用JS的input框

 <td><input type="file" id="file" name="file" accept="application/vnd.ms-excel,application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" onchange="fileChange(this);"></td>

 

原文鏈接：https://www.jianshu.com/p/85059c9752d8