javascript - 从 Controller 获取 Json 值到 jquery

Question

我有一个 JS 函数:

$(document).on('click', '#submitForm', function (e) {
var fileName = $('#fileName').val();
$.ajax({
    type: 'POST',
    url: '/Calculation/FileExist',
    data: { 'fileName': fileName },
    dataType: 'bool',
    success: function (result) {
        if (result.returnvalue) {
            e.preventDefault();
            alert(result.returnvalue);
            alert("The filename already exists. Please choose another one");
        }
        else {
            alert("The file doesn't exist");
        }
    }
});
});

我的行动:

    public ActionResult FileExist(string fileName)
    {
        bool result = true;
        string path = Server.MapPath(TempPath) + fileName + ".xlsx"; //Path for the file
        string[] Files = Directory.GetFiles(Server.MapPath(TempPath));
        for (int i = 0; i < Files.Length; i++)
        {
            if (path == Files[i])
            {
                //The filename already exists
                result = false;
            }
        }
        return Json(new { returnvalue = result });
    }

我在这里做错了什么？我正在尝试从 FileExist 方法获取 bool 值，如果为 true，则停止提交表单 (e.preventDefault)

Answer 1

没有数据类型:'bool'。请使用 dataType:'json' dataType:'text' 发送 bool 值

在你的情况下，它应该是dataType:'json'

$.ajax({
    type: 'POST',
    url: '/Calculation/FileExist',
    data: { 'fileName': fileName },
    dataType: 'json',
    success: function (result) {
        if (result.returnvalue) {
            e.preventDefault();
            alert(result.returnvalue);
            alert("The filename already exists. Please choose another one");
        }
        else {
            alert("The file doesn't exist");
        }
    }
});

然后

[HttpPost]
public ActionResult FileExist(string fileName)
{
}