Xamarin表单：AppDelegate中的System.NullReferenceException
嗨，我第一次尝试为IOS编译我的应用程序，但我得到了以下结果：Xamarin表单：AppDelegate中的System.NullReferenceException,xamarin,xamarin.forms,Xamarin,Xamarin.forms,嗨，我第一次尝试为IOS编译我的应用程序，但我得到了以下结果： <StackLayout WidthRequest="10000"> <StackLayout x:Name="LogoStack" BackgroundColor="White"> <Image x:Name="Image" Source="a.png"
<StackLayout WidthRequest="10000">
<StackLayout x:Name="LogoStack" BackgroundColor="White">
<Image x:Name="Image"
Source="a.png"
HeightRequest="120"
WidthRequest="120"
HorizontalOptions="Center">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="EasterCount"/>
</Image.GestureRecognizers>
</Image>
</StackLayout>
<StackLayout x:Name="StackList" IsVisible="True" HeightRequest="3000">
<ListView x:Name="PageList"
HasUnevenRows="True"
ItemTapped="Link_ItemTapped"
HeightRequest="25"
BackgroundColor="White">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Margin="0,0,0,0" BackgroundColor="#e7e7e7" HeightRequest="65" Padding="0">
<Grid x:Name="DeleteStack" VerticalOptions="CenterAndExpand" BackgroundColor="White" HorizontalOptions="FillAndExpand" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="50" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="28" />
<RowDefinition Height="22" />
<RowDefinition Height="1" />
</Grid.RowDefinitions>
<Label Grid.Column="0" Grid.Row="0" Text="{Binding Title}" LineBreakMode="TailTruncation" FontSize="25" Margin="20,0,0,0"/>
<Label Grid.Column="0" Grid.Row="1" Text="{Binding Link}" LineBreakMode="TailTruncation" FontSize="17" Margin="20,0,0,0"/>
<Image Margin="0,0,20,0"
IsVisible="{Binding IsVisible}"
Grid.Column="1"
Grid.Row="0"
Grid.RowSpan="2"
x:Name="DeleteButton"
Source="delete.png"
VerticalOptions="Center"
HeightRequest="20"
HorizontalOptions="Center"/>
</Grid>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
<StackLayout x:Name="FirstTimeOpenStack" HorizontalOptions="Center">
<Label Text="Please tap on the plus icon in the top right corner to add a website" />
</StackLayout>
</StackLayout>
<StackLayout WidthRequest="10000">
<StackLayout x:Name="LogoStack" BackgroundColor="White">
<Image x:Name="Image"
Source="a.png"
HeightRequest="120"
WidthRequest="120"
HorizontalOptions="Center">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="EasterCount"/>
</Image.GestureRecognizers>
</Image>
</StackLayout>
<StackLayout x:Name="StackList" IsVisible="True" HeightRequest="3000">
<ListView x:Name="PageList"
HasUnevenRows="True"
ItemTapped="Link_ItemTapped"
HeightRequest="25"
BackgroundColor="White">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Margin="0,0,0,0" BackgroundColor="#e7e7e7" HeightRequest="65" Padding="0">
<Grid x:Name="DeleteStack" VerticalOptions="CenterAndExpand" BackgroundColor="White" HorizontalOptions="FillAndExpand" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="50" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="28" />
<RowDefinition Height="22" />
<RowDefinition Height="1" />
</Grid.RowDefinitions>
<Label Grid.Column="0" Grid.Row="0" Text="{Binding Title}" LineBreakMode="TailTruncation" FontSize="25" Margin="20,0,0,0"/>
<Label Grid.Column="0" Grid.Row="1" Text="{Binding Link}" LineBreakMode="TailTruncation" FontSize="17" Margin="20,0,0,0"/>
<Image Margin="0,0,20,0"
IsVisible="{Binding IsVisible}"
Grid.Column="1"
Grid.Row="0"
Grid.RowSpan="2"
x:Name="DeleteButton"
Source="delete.png"
VerticalOptions="Center"
HeightRequest="20"
HorizontalOptions="Center"/>
</Grid>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
<StackLayout x:Name="FirstTimeOpenStack" HorizontalOptions="Center">
<Label Text="Please tap on the plus icon in the top right corner to add a website" />
</StackLayout>
</StackLayout>
returnbase.FinishedLaunching（应用程序，选项）
<StackLayout WidthRequest="10000">
<StackLayout x:Name="LogoStack" BackgroundColor="White">
<Image x:Name="Image"
Source="a.png"
HeightRequest="120"
WidthRequest="120"
HorizontalOptions="Center">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="EasterCount"/>
</Image.GestureRecognizers>
</Image>
</StackLayout>
<StackLayout x:Name="StackList" IsVisible="True" HeightRequest="3000">
<ListView x:Name="PageList"
HasUnevenRows="True"
ItemTapped="Link_ItemTapped"
HeightRequest="25"
BackgroundColor="White">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Margin="0,0,0,0" BackgroundColor="#e7e7e7" HeightRequest="65" Padding="0">
<Grid x:Name="DeleteStack" VerticalOptions="CenterAndExpand" BackgroundColor="White" HorizontalOptions="FillAndExpand" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="50" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="28" />
<RowDefinition Height="22" />
<RowDefinition Height="1" />
</Grid.RowDefinitions>
<Label Grid.Column="0" Grid.Row="0" Text="{Binding Title}" LineBreakMode="TailTruncation" FontSize="25" Margin="20,0,0,0"/>
<Label Grid.Column="0" Grid.Row="1" Text="{Binding Link}" LineBreakMode="TailTruncation" FontSize="17" Margin="20,0,0,0"/>
<Image Margin="0,0,20,0"
IsVisible="{Binding IsVisible}"
Grid.Column="1"
Grid.Row="0"
Grid.RowSpan="2"
x:Name="DeleteButton"
Source="delete.png"
VerticalOptions="Center"
HeightRequest="20"
HorizontalOptions="Center"/>
</Grid>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
<StackLayout x:Name="FirstTimeOpenStack" HorizontalOptions="Center">
<Label Text="Please tap on the plus icon in the top right corner to add a website" />
</StackLayout>
</StackLayout>
我对xamarin比较陌生，所以我很抱歉我的不了解
<StackLayout WidthRequest="10000">
<StackLayout x:Name="LogoStack" BackgroundColor="White">
<Image x:Name="Image"
Source="a.png"
HeightRequest="120"
WidthRequest="120"
HorizontalOptions="Center">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="EasterCount"/>
</Image.GestureRecognizers>
</Image>
</StackLayout>
<StackLayout x:Name="StackList" IsVisible="True" HeightRequest="3000">
<ListView x:Name="PageList"
HasUnevenRows="True"
ItemTapped="Link_ItemTapped"
HeightRequest="25"
BackgroundColor="White">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Margin="0,0,0,0" BackgroundColor="#e7e7e7" HeightRequest="65" Padding="0">
<Grid x:Name="DeleteStack" VerticalOptions="CenterAndExpand" BackgroundColor="White" HorizontalOptions="FillAndExpand" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="50" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="28" />
<RowDefinition Height="22" />
<RowDefinition Height="1" />
</Grid.RowDefinitions>
<Label Grid.Column="0" Grid.Row="0" Text="{Binding Title}" LineBreakMode="TailTruncation" FontSize="25" Margin="20,0,0,0"/>
<Label Grid.Column="0" Grid.Row="1" Text="{Binding Link}" LineBreakMode="TailTruncation" FontSize="17" Margin="20,0,0,0"/>
<Image Margin="0,0,20,0"
IsVisible="{Binding IsVisible}"
Grid.Column="1"
Grid.Row="0"
Grid.RowSpan="2"
x:Name="DeleteButton"
Source="delete.png"
VerticalOptions="Center"
HeightRequest="20"
HorizontalOptions="Center"/>
</Grid>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
<StackLayout x:Name="FirstTimeOpenStack" HorizontalOptions="Center">
<Label Text="Please tap on the plus icon in the top right corner to add a website" />
</StackLayout>
</StackLayout>
以下是我的完整AppDelegate：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Drawing;
using System.Globalization;
using System.IO;
using Flex;
using Foundation;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;
using System.Xml.Linq;
namespace dpsApp.iOS
{
[Register("AppDelegate")]
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
global::Xamarin.Forms.Forms.Init();
Rg.Plugins.Popup.Popup.Init();
FlexButton.Init();
LoadApplication(new App());
return base.FinishedLaunching(app, options);
}
}
<StackLayout WidthRequest="10000">
<StackLayout x:Name="LogoStack" BackgroundColor="White">
<Image x:Name="Image"
Source="a.png"
HeightRequest="120"
WidthRequest="120"
HorizontalOptions="Center">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="EasterCount"/>
</Image.GestureRecognizers>
</Image>
</StackLayout>
<StackLayout x:Name="StackList" IsVisible="True" HeightRequest="3000">
<ListView x:Name="PageList"
HasUnevenRows="True"
ItemTapped="Link_ItemTapped"
HeightRequest="25"
BackgroundColor="White">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Margin="0,0,0,0" BackgroundColor="#e7e7e7" HeightRequest="65" Padding="0">
<Grid x:Name="DeleteStack" VerticalOptions="CenterAndExpand" BackgroundColor="White" HorizontalOptions="FillAndExpand" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="50" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="28" />
<RowDefinition Height="22" />
<RowDefinition Height="1" />
</Grid.RowDefinitions>
<Label Grid.Column="0" Grid.Row="0" Text="{Binding Title}" LineBreakMode="TailTruncation" FontSize="25" Margin="20,0,0,0"/>
<Label Grid.Column="0" Grid.Row="1" Text="{Binding Link}" LineBreakMode="TailTruncation" FontSize="17" Margin="20,0,0,0"/>
<Image Margin="0,0,20,0"
IsVisible="{Binding IsVisible}"
Grid.Column="1"
Grid.Row="0"
Grid.RowSpan="2"
x:Name="DeleteButton"
Source="delete.png"
VerticalOptions="Center"
HeightRequest="20"
HorizontalOptions="Center"/>
</Grid>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
<StackLayout x:Name="FirstTimeOpenStack" HorizontalOptions="Center">
<Label Text="Please tap on the plus icon in the top right corner to add a website" />
</StackLayout>
</StackLayout>
}
<StackLayout WidthRequest="10000">
<StackLayout x:Name="LogoStack" BackgroundColor="White">
<Image x:Name="Image"
Source="a.png"
HeightRequest="120"
WidthRequest="120"
HorizontalOptions="Center">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="EasterCount"/>
</Image.GestureRecognizers>
</Image>
</StackLayout>
<StackLayout x:Name="StackList" IsVisible="True" HeightRequest="3000">
<ListView x:Name="PageList"
HasUnevenRows="True"
ItemTapped="Link_ItemTapped"
HeightRequest="25"
BackgroundColor="White">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Margin="0,0,0,0" BackgroundColor="#e7e7e7" HeightRequest="65" Padding="0">
<Grid x:Name="DeleteStack" VerticalOptions="CenterAndExpand" BackgroundColor="White" HorizontalOptions="FillAndExpand" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="50" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="28" />
<RowDefinition Height="22" />
<RowDefinition Height="1" />
</Grid.RowDefinitions>
<Label Grid.Column="0" Grid.Row="0" Text="{Binding Title}" LineBreakMode="TailTruncation" FontSize="25" Margin="20,0,0,0"/>
<Label Grid.Column="0" Grid.Row="1" Text="{Binding Link}" LineBreakMode="TailTruncation" FontSize="17" Margin="20,0,0,0"/>
<Image Margin="0,0,20,0"
IsVisible="{Binding IsVisible}"
Grid.Column="1"
Grid.Row="0"
Grid.RowSpan="2"
x:Name="DeleteButton"
Source="delete.png"
VerticalOptions="Center"
HeightRequest="20"
HorizontalOptions="Center"/>
</Grid>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
<StackLayout x:Name="FirstTimeOpenStack" HorizontalOptions="Center">
<Label Text="Please tap on the plus icon in the top right corner to add a website" />
</StackLayout>
</StackLayout>
这是我的主页XAML：
`
<StackLayout WidthRequest="10000">
<StackLayout x:Name="LogoStack" BackgroundColor="White">
<Image x:Name="Image"
Source="a.png"
HeightRequest="120"
WidthRequest="120"
HorizontalOptions="Center">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="EasterCount"/>
</Image.GestureRecognizers>
</Image>
</StackLayout>
<StackLayout x:Name="StackList" IsVisible="True" HeightRequest="3000">
<ListView x:Name="PageList"
HasUnevenRows="True"
ItemTapped="Link_ItemTapped"
HeightRequest="25"
BackgroundColor="White">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Margin="0,0,0,0" BackgroundColor="#e7e7e7" HeightRequest="65" Padding="0">
<Grid x:Name="DeleteStack" VerticalOptions="CenterAndExpand" BackgroundColor="White" HorizontalOptions="FillAndExpand" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="50" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="28" />
<RowDefinition Height="22" />
<RowDefinition Height="1" />
</Grid.RowDefinitions>
<Label Grid.Column="0" Grid.Row="0" Text="{Binding Title}" LineBreakMode="TailTruncation" FontSize="25" Margin="20,0,0,0"/>
<Label Grid.Column="0" Grid.Row="1" Text="{Binding Link}" LineBreakMode="TailTruncation" FontSize="17" Margin="20,0,0,0"/>
<Image Margin="0,0,20,0"
IsVisible="{Binding IsVisible}"
Grid.Column="1"
Grid.Row="0"
Grid.RowSpan="2"
x:Name="DeleteButton"
Source="delete.png"
VerticalOptions="Center"
HeightRequest="20"
HorizontalOptions="Center"/>
</Grid>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
<StackLayout x:Name="FirstTimeOpenStack" HorizontalOptions="Center">
<Label Text="Please tap on the plus icon in the top right corner to add a website" />
</StackLayout>
</StackLayout>
您的应用程序代理看起来正常。您正在启动的应用（）中存在未处理的异常
<StackLayout WidthRequest="10000">
<StackLayout x:Name="LogoStack" BackgroundColor="White">
<Image x:Name="Image"
Source="a.png"
HeightRequest="120"
WidthRequest="120"
HorizontalOptions="Center">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="EasterCount"/>
</Image.GestureRecognizers>
</Image>
</StackLayout>
<StackLayout x:Name="StackList" IsVisible="True" HeightRequest="3000">
<ListView x:Name="PageList"
HasUnevenRows="True"
ItemTapped="Link_ItemTapped"
HeightRequest="25"
BackgroundColor="White">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Margin="0,0,0,0" BackgroundColor="#e7e7e7" HeightRequest="65" Padding="0">
<Grid x:Name="DeleteStack" VerticalOptions="CenterAndExpand" BackgroundColor="White" HorizontalOptions="FillAndExpand" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="50" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="28" />
<RowDefinition Height="22" />
<RowDefinition Height="1" />
</Grid.RowDefinitions>
<Label Grid.Column="0" Grid.Row="0" Text="{Binding Title}" LineBreakMode="TailTruncation" FontSize="25" Margin="20,0,0,0"/>
<Label Grid.Column="0" Grid.Row="1" Text="{Binding Link}" LineBreakMode="TailTruncation" FontSize="17" Margin="20,0,0,0"/>
<Image Margin="0,0,20,0"
IsVisible="{Binding IsVisible}"
Grid.Column="1"
Grid.Row="0"
Grid.RowSpan="2"
x:Name="DeleteButton"
Source="delete.png"
VerticalOptions="Center"
HeightRequest="20"
HorizontalOptions="Center"/>
</Grid>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
<StackLayout x:Name="FirstTimeOpenStack" HorizontalOptions="Center">
<Label Text="Please tap on the plus icon in the top right corner to add a website" />
</StackLayout>
</StackLayout>
以下是捕获未处理异常的一种方法：
<StackLayout WidthRequest="10000">
<StackLayout x:Name="LogoStack" BackgroundColor="White">
<Image x:Name="Image"
Source="a.png"
HeightRequest="120"
WidthRequest="120"
HorizontalOptions="Center">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="EasterCount"/>
</Image.GestureRecognizers>
</Image>
</StackLayout>
<StackLayout x:Name="StackList" IsVisible="True" HeightRequest="3000">
<ListView x:Name="PageList"
HasUnevenRows="True"
ItemTapped="Link_ItemTapped"
HeightRequest="25"
BackgroundColor="White">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Margin="0,0,0,0" BackgroundColor="#e7e7e7" HeightRequest="65" Padding="0">
<Grid x:Name="DeleteStack" VerticalOptions="CenterAndExpand" BackgroundColor="White" HorizontalOptions="FillAndExpand" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="50" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="28" />
<RowDefinition Height="22" />
<RowDefinition Height="1" />
</Grid.RowDefinitions>
<Label Grid.Column="0" Grid.Row="0" Text="{Binding Title}" LineBreakMode="TailTruncation" FontSize="25" Margin="20,0,0,0"/>
<Label Grid.Column="0" Grid.Row="1" Text="{Binding Link}" LineBreakMode="TailTruncation" FontSize="17" Margin="20,0,0,0"/>
<Image Margin="0,0,20,0"
IsVisible="{Binding IsVisible}"
Grid.Column="1"
Grid.Row="0"
Grid.RowSpan="2"
x:Name="DeleteButton"
Source="delete.png"
VerticalOptions="Center"
HeightRequest="20"
HorizontalOptions="Center"/>
</Grid>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
<StackLayout x:Name="FirstTimeOpenStack" HorizontalOptions="Center">
<Label Text="Please tap on the plus icon in the top right corner to add a website" />
</StackLayout>
</StackLayout>
namespace WiFiVisualPager.iOS
{
// The UIApplicationDelegate for the application. This class is responsible for launching the
// User Interface of the application, as well as listening (and optionally responding) to
// application events from iOS.
[Register("AppDelegate")]
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
//
// This method is invoked when the application has loaded and is ready to run. In this
// method you should instantiate the window, load the UI into it and then make the window
// visible.
//
// You have 17 seconds to return from this method, or iOS will terminate your application.
//
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
AppDomain.CurrentDomain.UnhandledException += CurrentDomainOnUnhandledException;
TaskScheduler.UnobservedTaskException += TaskSchedulerOnUnobservedTaskException;
global::Xamarin.Forms.Forms.Init();
DisplayCrashReport();
LoadApplication(new App());
return base.FinishedLaunching(app, options);
}
#region [Error handling]
//Credit: Peter Norman.
//https://peterno.wordpress.com/2015/04/15/unhandled-exception-handling-in-ios-and-android-with-xamarin/
//Minor compile fixes by David McCurley.
private static void TaskSchedulerOnUnobservedTaskException(object sender, UnobservedTaskExceptionEventArgs unobservedTaskExceptionEventArgs)
{
var newExc = new Exception("TaskSchedulerOnUnobservedTaskException", unobservedTaskExceptionEventArgs.Exception);
LogUnhandledException(newExc);
}
private static void CurrentDomainOnUnhandledException(object sender, UnhandledExceptionEventArgs unhandledExceptionEventArgs)
{
var newExc = new Exception("CurrentDomainOnUnhandledException", unhandledExceptionEventArgs.ExceptionObject as Exception);
LogUnhandledException(newExc);
}
internal static void LogUnhandledException(Exception exception)
{
try
{
const string errorFileName = "Fatal.log";
var libraryPath = System.Environment.GetFolderPath(Environment.SpecialFolder.Resources); // iOS: Environment.SpecialFolder.Resources
var errorFilePath = Path.Combine(libraryPath, errorFileName);
var errorMessage = String.Format("Time: {0}\r\nError: Unhandled Exception\r\n{1}",
DateTime.Now, exception.ToString());
File.WriteAllText(errorFilePath, errorMessage);
// Log to Android Device Logging.
//Android.Util.Log.Error("Crash Report", errorMessage);
}
catch
{
// just suppress any error logging exceptions
}
}
/// <summary>
// If there is an unhandled exception, the exception information is diplayed
// on screen the next time the app is started (only in debug configuration)
/// </summary>
[Conditional("DEBUG")]
private static void DisplayCrashReport()
{
const string errorFilename = "Fatal.log";
var libraryPath = Environment.GetFolderPath(Environment.SpecialFolder.Resources);
var errorFilePath = Path.Combine(libraryPath, errorFilename);
if (!File.Exists(errorFilePath))
{
return;
}
var errorText = File.ReadAllText(errorFilePath);
var alertView = new UIAlertView("Crash Report", errorText, null, "Close", "Clear") { UserInteractionEnabled = true };
alertView.Clicked += (sender, args) =>
{
if (args.ButtonIndex != 0)
{
File.Delete(errorFilePath);
}
};
alertView.Show();
}
#endregion
}
}
名称空间wifivisualpage.iOS
{
//应用程序的UIApplicationLegate。此类负责启动
//应用程序的用户界面，以及对
//来自iOS的应用程序事件。
[注册（“AppDelegate”）]
公共部分类AppDelegate:global:：Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
//
//当应用程序已加载并准备运行时，将调用此方法
//方法，您应该实例化窗口，将UI加载到其中，然后创建窗口
//看得见。
//
//您有17秒的时间从该方法返回，否则iOS将终止您的应用程序。
//
公共覆盖bool FinishedLaunching（UIApplication应用程序、NSDictionary选项）
{
AppDomain.CurrentDomain.UnhandledException+=CurrentDomainOnUnhandledException；
TaskScheduler.UnobservedTaskeException+=TaskScheduleRonUnobservedTaskeException；
全局：：Xamarin.Forms.Forms.Init（）；
DisplayCrashReport（）；
加载应用程序（新应用程序（））；
返回基地。完成发射（应用程序，选项）；
}
#区域[错误处理]
//信贷：彼得·诺曼。
//https://peterno.wordpress.com/2015/04/15/unhandled-exception-handling-in-ios-and-android-with-xamarin/
//David McCurley的小编译修复。
私有静态void taskScheduleRonUnobservedTaskeException（对象发送方，UnobservedTaskeExceptionEventArgs UnobservedTaskeExceptionEventArgs）
{
var newExc=新异常（“TaskSchedulerOnUnobservedTaskException”，UnobservedTaskExceptionEventTargets.Exception）；
日志未处理异常（newExc）；
}
私有静态void CurrentDomainOnUnhandledException（对象发送方，UnhandledExceptionEventArgs UnhandledExceptionEventArgs）
{
var newExc=新异常（“CurrentDomainOnUnhandledException”，UnhandledExceptionEventTargets.ExceptionObject作为异常）；
日志未处理异常（newExc）；
}
内部静态无效日志未处理异常（异常）
{
尝试
{
常量字符串errorFileName=“Fatal.log”；
var libraryPath=System.Environment.GetFolderPath（Environment.SpecialFolder.Resources）；//iOS:Environment.SpecialFolder.Resources
var errorFilePath=Path.Combine（libraryPath，errorFileName）；
var errorMessage=String.Format（“时间：{0}\r\n错误：未处理的异常\r\n{1}”，
DateTime.Now，exception.ToString（））；
WriteAllText（errorFilePath，errorMessage）；
//登录到Android设备日志。
//Android.Util.Log.Error（“崩溃报告”，errorMessage）；
}
抓住
{
//只需抑制任何错误记录异常
}
}
///
//如果存在未处理的异常，则显示异常信息
//下一次启动应用程序时在屏幕上显示（仅在调试配置中）
///
[有条件的（“调试”）]
私有静态void DisplayCrashReport（）
{
常量字符串errorFilename=“Fatal.log”；
var libraryPath=Environment.GetFolderPath（Environment.SpecialFolder.Resources）；
var errorFilePath=Path.Combine（libraryPath，errorFilename）；
如果（！File.Exists（errorFilePath））
{
返回；
}
var errorText=File.ReadAllText（errorFilePath）；
var-alertView=new-UIAlertView（“崩溃报告”，errorText，null，“关闭”，“清除”）{UserInteractionEnabled=true}；
alertView.Clicked+=（发件人，参数）=>
{
如果（args.ButtonIndex！=0）
{
Delete（errorFilePath）；
}
};
alertView.Show（）；
}
#端区
}
}
您的应用程序代理看起来正常。应用程序中的某个位置存在未处理的异常