以下代码成功从Web服务获取数据并将其显示在Windows 8桌面应用程序中。
HttpClient client = new HttpClient();
HttpResponseMessage response = await client.GetAsync("http://localhost:12345/api/items");
var info = new List<SampleDataGroup>();
if (response.IsSuccessStatusCode)
{
var content = await response.Content.ReadAsStringAsync();
var item = JsonConvert.DeserializeObject<dynamic>(content);
foreach (var data in item)
{
var infoSect = new SampleDataGroup
(
(string)data.Id.ToString(),
(string)data.Name,
(string)"",
(string)data.PhotoUrl,
(string)data.Description
);
info.Add(infoSect);
}
}
else
{
MessageDialog dlg = new MessageDialog("Error");
await dlg.ShowAsync();
}
但是,这需要互联网连接才能工作。每次没有互联网连接时,应用程序都会崩溃。
如果网络连接不起作用,如何在此代码中编写try catch
语句以显示弹出消息?
修改
我正在尝试使用下面的MessageDialog
,这会阻止应用崩溃,但它不会显示消息。
catch (Exception ex)
{
MessageDialog err = new MessageDialog(ex.Message);
}
答案 0 :(得分:0)
你不需要
string errorMessage = string.Empty;
try
{
HttpClient client = new HttpClient();
HttpResponseMessage response = await
client.GetAsync("http://localhost:12345/api/items");
var info = new List<SampleDataGroup>();
if (response.IsSuccessStatusCode)
{
var content = await response.Content.ReadAsStringAsync();
var item = JsonConvert.DeserializeObject<dynamic>(content);
foreach (var data in item)
{
var infoSect = new SampleDataGroup
(
(string)data.Id.ToString(),
(string)data.Name,
(string)"",
(string)data.PhotoUrl,
(string)data.Description
);
info.Add(infoSect);
}
}
else
{
errorMessage = "Error";
}
}
catch (Exception ex)
{
ErrorMessage = ex.Message;
}
if (errorMessage != string.Empty)
{
MessageDialog dlg = new MessageDialog(errorMessage);
await dlg.ShowAsync();
}