When you send an ajax request, specify the data type to be received as json 而你后端返回的数据不是json formats. Therefore, it is deemed that the request failed and a failure callback is entered.

And there may be something wrong with your back-end writing. The browser's response is an HTML page?

These places should be response.write('xxxx') right

Thenresponse.end()Let’s

Shouldn’t all backend response data be response.write?

Added:

I must have written it wrong

html

    <pre id="test">

    </pre>
    <pre id="test2">

    </pre>
    <script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
    <script>
        $.ajax({
            url: "./test.aspx",
            dataType: 'json'
        }).done(function (data) {
            // 指定为类型为json 则会将数据处理为对象的 即自动JSON.parse 了
            
            $('#test').text('data类型' + typeof data + '\n' + JSON.stringify(data, null, 4));
        }).fail(function () {
            alert('fail');
        });

        $.ajax({
            url: "./test.aspx"
        }).done(function (data) {
            alert('data类型' + typeof data + '\n');
            $('#test2').text('data类型' + typeof data + '\n' + data);
        }).fail(function () {
            alert('fail');
        });
    </script>

test.aspx.cs

protected void Page_Load(object sender, EventArgs e)
{   
    String str = @"[{
    ""guid"": ""410000197812057474"",
    ""name"": ""当进少头等程给进话团拉组层育除水"",
    ""url"": ""mailto://cixus.vg/wvgermuy"",
    ""date"": ""03-25"",
    ""status"": """",
    ""openType"": ""tabsnav""
}, {
    ""guid"": ""42000020111028506X"",
    ""name"": ""张度联酸做电往"",
    ""url"": ""mailto://pslic.sa/mhsgmxqur"",
    ""date"": ""08-08"",
    ""status"": """",
    ""openType"": ""dialog""
}, {
    ""guid"": ""520000199308053591"",
    ""name"": ""政劳则加派党王存才从她"",
    ""url"": ""telnet://lvgoxn.iq/imsfzmfjk"",
    ""date"": ""06-06"",
    ""status"": """",
    ""openType"": ""dialog""
}]";
    Response.Write(str);
    Response.End();
}

ajax removes datatype:json
or Response.Write returns json format data

When returning in the background, change it to:

return {
    success: true
}