我正在研究 WinRT。如果抛出未处理的异常,我想将消息文本写入存储。 我在“App.xaml.cs”中添加了一个事件处理程序,请参阅代码。
异常被捕获但是最后一行,也就是写入文件的地方,再次崩溃 -> 'exception'!
为什么?有什么想法吗?
public App()
{
this.InitializeComponent();
this.Suspending += OnSuspending;
this.UnhandledException += App_UnhandledException;
}
async void App_UnhandledException(object sender, UnhandledExceptionEventArgs e)
{
StorageFolder folder = Windows.Storage.ApplicationData.Current.LocalFolder;
StorageFile file= await folder.CreateFileAsync("crash.log",CreationCollisionOption.OpenIfExists);
await FileIO.AppendTextAsync(file, e.Message); // <----- crash again -----
}
谢谢
晴天
最佳答案
我一直在想同样的事情,并且在我的搜索中很早就偶然发现了这个。我找到了一种方法,希望这对其他人也有用。
问题是 await
正在返回对 UI 线程的控制,并且应用程序崩溃了。您需要延期,但没有真正的方法可以延期。
我的解决方案是改用设置存储。我假设大多数想要这样做的人都想做一些 LittleWatson 风格的事情,所以这里有一些代码修改自 http://blogs.msdn.com/b/andypennell/archive/2010/11/01/error-reporting-on-windows-phone-7.aspx为了您的方便:
namespace YourApp
{
using Windows.Storage;
using Windows.UI.Popups;
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;
public class LittleWatson
{
private const string settingname = "LittleWatsonDetails";
private const string email = "mailto:?to=you@example.com&subject=YourApp auto-generated problem report&body=";
private const string extra = "extra", message = "message", stacktrace = "stacktrace";
internal static void ReportException(Exception ex, string extraData)
{
ApplicationData.Current.LocalSettings.CreateContainer(settingname, Windows.Storage.ApplicationDataCreateDisposition.Always);
var exceptionValues = ApplicationData.Current.LocalSettings.Containers[settingname].Values;
exceptionValues[extra] = extraData;
exceptionValues[message] = ex.Message;
exceptionValues[stacktrace] = ex.StackTrace;
}
internal async static Task CheckForPreviousException()
{
var container = ApplicationData.Current.LocalSettings.Containers;
try
{
var exceptionValues = container[settingname].Values;
string extraData = exceptionValues[extra] as string;
string messageData = exceptionValues[message] as string;
string stacktraceData = exceptionValues[stacktrace] as string;
var sb = new StringBuilder();
sb.AppendLine(extraData);
sb.AppendLine(messageData);
sb.AppendLine(stacktraceData);
string contents = sb.ToString();
SafeDeleteLog();
if (stacktraceData != null && stacktraceData.Length > 0)
{
var dialog = new MessageDialog("A problem occured the last time you ran this application. Would you like to report it so that we can fix the error?", "Error Report")
{
CancelCommandIndex = 1,
DefaultCommandIndex = 0
};
dialog.Commands.Add(new UICommand("Send", async delegate
{
var mailToSend = email.ToString();
mailToSend += contents;
var mailto = new Uri(mailToSend);
await Windows.System.Launcher.LaunchUriAsync(mailto);
}));
dialog.Commands.Add(new UICommand("Cancel"));
await dialog.ShowAsync();
}
}
catch (KeyNotFoundException)
{
// KeyNotFoundException will fire if we've not ever had crash data. No worries!
}
}
private static void SafeDeleteLog()
{
ApplicationData.Current.LocalSettings.CreateContainer(settingname, Windows.Storage.ApplicationDataCreateDisposition.Always);
var exceptionValues = ApplicationData.Current.LocalSettings.Containers[settingname].Values;
exceptionValues[extra] = string.Empty;
exceptionValues[message] = string.Empty;
exceptionValues[stacktrace] = string.Empty;
}
}
}
要实现它,您需要按照上面的链接执行相同的操作,但要确保数据在此处,以防 url 出现故障:
App.xaml.cs
构造函数(在调用 this.InitializeComponent()
之前):
this.UnhandledException += (s, e) => LittleWatson.ReportException(e.Exception, "extra message goes here");
显然,如果您已经有一个 UnhandledException 方法,您可以在其中调用 LittleWatson。
如果您使用的是 Windows 8.1,您也可以添加 NavigationFailed 调用。这需要在实际页面中(通常是 MainPage.xaml.cs 或任何首次打开的页面):
xx.xaml.cs
构造函数(任何给定页面):
rootFrame.NavigationFailed += (s, e) => LittleWatson.ReportException(e.Exception, "extra message goes here");
最后,您需要询问用户是否要在应用重新打开时发送电子邮件。在应用的默认页面构造函数中(默认:页面 App.xaml.cs 初始化):
this.Loaded += async (s, e) => await LittleWatson.CheckForPreviousException();
或者,如果您已经使用了 OnLoad 方法,则添加对它的调用。
关于c# - WinRT C# : Cannot save UnhandledException to Storage,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/15000769/