从控制器发送阵列中的MVC使用JSON视图 [英] send array from controller to a view using JSON in MVC

问题描述

我有这样的code：

var mapcity = new Array([]);              

         $.ajax({
             type: 'GET',
             url: '/home/DrawMap',
             dataType: 'json',
             success: function (data) {

                 var len = data.length;

                 for (var i = 0; i < len; i++) {

                    // mapcity['' + data[i].name + ''] = { center: new google.maps.LatLng(data[i].x, data[i].y), population: data[i].population, name: '' + data[i].name + '' };
                     mapcity['' + data[i].name + ''] = { center: new google.maps.LatLng(data[i].x, data[i].y), population: data[i].population, name: ''+data[i].name+'' };
                     //newarr[i] = data[i].name;

                   alert(mapcity[0].population)
                 }
                 }
         });
}

这是我的code的一部分，这是从控制器内的功能：

This is a part of my code, and this is the function from controller :

public ActionResult DrawMap() {   

  string data = "[{ 'x':31.949454,'y': 35.932913,'population':50000,'name':'amman'},{ 'x':33.79,'y': 33.39,'population':100000,'name':'Zarqa'}]";
        data=data.Replace("'","\"");
        return this.Content(data, "application/json");       

    }

当我运行它，它的HET从控制器，但没有保存到mapcity变量JSON数据！
它什么都不做。我怎么能解决这个问题，什么IAM做错了吗？

When I run this, its het the JSON data from the controller but without saving it into the mapcity variable! And it does nothing. how can I solve it and what iam doing wrong?

推荐答案

您不应该手动构建JSON你没有，但总是用JSON序列化：

You should never be manually building JSON as you did but always use a JSON serializer:

public ActionResult DrawMap() 
{
    var data = new[]
    {
        new
        {
            x = 31.949454,
            y = 35.932913,
            population = 50000,
            name = "amman",
        },
        new
        {
            x = 33.79,
            y = 33.39,
            population = 100000,
            name = "Zarqa",
        }
    };

    return Json(data, JsonRequestBehavior.AllowGet);
}

你也已经宣布了成功处理程序这是导致我到以为你试图将$就调用后立即使用它的价值以外的 mapcity 变量，显然是不可能的，因为AJAX就其自己的本性是异步的。这意味着，成功回调可能很久以后执行，$就调用立即返回。

Also you have declared your mapcity variable outside of the success handler which is leading me into thinking that you are attempting to use its value immediately after the $.ajax call which obviously is not possible because AJAX by its very own nature is asynchronous. This means that the success callback could be executed much later and the $.ajax call returns immediately.

因此​​，要使用这个变量的唯一一个安全的地方就是在成功的功能：

So the only single safe place to use this variable is INSIDE the success function:

$.ajax({
    type: 'GET',
    url: '/home/DrawMap',
    success: function (data) {
        var mapcity = {};
        var len = data.length;
        for (var i = 0; i < len; i++) {
            mapcity['' + data[i].name + ''] = { center: new google.maps.LatLng(data[i].x, data[i].y), population: data[i].population, name: ''+data[i].name+'' };
        }
    }
});

您也有另外一个问题。您声明 mapcity 变量数组（新的Array（[]）），然后您试图插入非整数索引进去：

You also have another problem. You declared mapcity variable as array (new Array([])) and then you attempted to insert non-integer indexes into it:

mapcity['' + data[i].name + '']

在JavaScript的，当你声明一个数组，它只能有0基于整数索引。所以，你既可以其声明为JavaScript对象变种 mapcity = {}; 或者用整只索引

In javascript when you declare an array, it can only have 0 based integer indexes. So you could either declare it as a javascript object var mapcity = {}; or use integer indexes only.

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