问题描述
我正在尝试使用 ASP.NET Web API 将列表返回到 Xamarin,并使用 Prism MvvM 框架使用 Xamarin Forms。
我有一个 API,它以 JSON 格式返回一个列表,下面是示例。这通过邮递员正确返回数据(我相信):
public async Task<List<OpenWorkOrder>> GetopenWorkOrders()
{
using (WO db = new WO())
{
List<OpenWorkOrder> woLog = await db.OpenWorkOrders
.OrderBy(x => x.WOID)
.ToListAsync();
return woLog;
}
}
以下是 postman 返回的数据示例:
[
{
"WOID": "M0000001","AssetNumber": "Item 2","WorkRequested": null,"Active": true,"ID": 1
},{
"WOID": "M0000002","AssetNumber": "Item 1","ID": 2
}
]
我正在努力将它绑定到 Xamarin Forms 中的 ListView。 我想使用一个按钮导航到一个页面,并在该页面上加载列表视图,供用户选择他们正在执行的工单。
这是视图和绑定:
<StackLayout>
<Label Text="Test"></Label>
<ListView ItemsSource="{Binding Openorders}"></ListView>
</StackLayout>
private object _openWO;
public object Openorders
{
get { return _openWO; }
set { SetProperty(ref _openWO,value); }
}
private async Task<OpenWorkOrder> OpenWO()
{
var client = new RestClient("http://apiurl/Maint/api/");
var request = new RestRequest("GetopenWorkOrders",Method.GET);
IRestResponse<OpenWorkOrder> response2 = await client.ExecuteAsync<OpenWorkOrder>(request);
var Openorders = response2.Data;
return Openorders;
}
public async void OnNavigatedTo(INavigationParameters parameters)
{
try { await OpenWO();
Console.WriteLine("Await Called!"); }
catch (Exception ex)
{
await _dialogService.displayAlertAsync("Exception Handled",ex.ToString(),"OK");
}
}
当我导航到它时,屏幕打开得很好,我看到它运行 Write Line,我只是不知道为什么我在表单上看不到任何数据。
我在哪里搞砸了?
编辑: 与 Jason 交谈后,这里是一些更新的代码。
private List<OpenWorkOrder> _openWO;
public List<OpenWorkOrder> Openorders
{
get { return _openWO; }
set { SetProperty(ref _openWO,value); }
}
关于更新的代码:
private async Task<OpenWorkOrder> OpenWO()
{
var client = new RestClient("apiurl/api/");
var request = new RestRequest("GetopenWorkOrders",Method.GET);
IRestResponse<OpenWorkOrder> response2 = await client.ExecuteAsync<OpenWorkOrder>(request);
if (response2.StatusCode.ToString() == "OK")
{
Console.WriteLine("RESPONSE DATA!!!!" +response2.Content+"RESPONSE DATA!!!!");
var Openorders = response2.Data;
return Openorders;
}
else
{
Console.WriteLine("Response status code: " + response2.StatusCode.ToString());
return null;
}
}
这是 OpenWorkOrder 类:
public class OpenWorkOrder
{
public int ID { get; set; }
public string WOID { get; set; }
public string AssetNumber { get; set; }
public string WorkRequested { get; set; }
public Nullable<bool> Active { get; set; }
}
解决方法
首先您需要修改您的 REST 请求以处理 List<OpenWorkOrder>
// this will return a List,not a single object
private async Task<List<OpenWorkOrder>> OpenWO()
{
var client = new RestClient("http://apiurl/Maint/api/");
var request = new RestRequest("GetOpenWorkOrders",Method.GET);
// get a list here too
IRestResponse<List<OpenWorkOrder>> response2 = await client.ExecuteAsync<OpenWorkOrder>(request);
// return a list
return response2.data;
}
然后在调用方法时,您需要将结果分配给您的属性
OpenOrders = await OpenWO();
Console.WriteLine("Await Called!"); }