Fixing: Android: Binding UpdateSourceTrigger with LostFocus crashes the app

Fixing: Binding UpdateSource/TargetTrigger set manually does not overwrite default value of event
Adding missing System.Runtime and System.Threading.Tasks references to Android
V5.2.1

GalaSoft.MvvmLight/GalaSoft.MvvmLight (PCL)/Properties/AssemblyInfo.cs

@@ -30,4 +30,4 @@ using System.Runtime.InteropServices;
 [assembly: CLSCompliant(true)]
 
 // BL0035
-[assembly: AssemblyVersion("5.2.0.*")]
+[assembly: AssemblyVersion("5.2.1.*")]

GalaSoft.MvvmLight/GalaSoft.MvvmLight (VS2013).sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 2013
-VisualStudioVersion = 12.0.31101.0
+# Visual Studio 14
+VisualStudioVersion = 14.0.23107.0
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "GalaSoft.MvvmLight (PCL)", "GalaSoft.MvvmLight (PCL)\GalaSoft.MvvmLight (PCL).csproj", "{6A912701-3BA1-4975-ADBF-160CAF66B640}"
 EndProject

GalaSoft.MvvmLight/GalaSoft.MvvmLight.Extras (PCL)/Properties/AssemblyInfo.cs

@@ -40,4 +40,4 @@ using System.Runtime.InteropServices;
 [assembly:NeutralResourcesLanguage("en-US")]
 
 // BL0035
-[assembly: AssemblyVersion("5.2.0.*")]
+[assembly: AssemblyVersion("5.2.1.*")]

GalaSoft.MvvmLight/GalaSoft.MvvmLight.Platform (Android)/GalaSoft.MvvmLight.Platform (Android).csproj

@@ -15,6 +15,7 @@
     <AndroidResgenFile>Resources\Resource.Designer.cs</AndroidResgenFile>
     <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
     <AndroidUseLatestPlatformSdk>True</AndroidUseLatestPlatformSdk>
+    <TargetFrameworkVersion>v5.1</TargetFrameworkVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -42,6 +43,8 @@
     <Reference Include="mscorlib" />
     <Reference Include="System" />
     <Reference Include="System.Core" />
+    <Reference Include="System.Runtime" />
+    <Reference Include="System.Threading.Tasks" />
     <Reference Include="System.Xml.Linq" />
     <Reference Include="System.Xml" />
   </ItemGroup>

GalaSoft.MvvmLight/GalaSoft.MvvmLight.Platform (Android)/Helpers/BindingGeneric.cs

@@ -20,8 +20,8 @@ using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Windows;
-
 #if ANDROID
+using Android.Views;
 using Android.Text;
 using Android.Widget;
 #endif
@@ -44,10 +44,10 @@ namespace GalaSoft.MvvmLight.Helpers
     {
         private readonly SimpleConverter _converter = new SimpleConverter();
         private readonly List<IWeakEventListener> _listeners = new List<IWeakEventListener>();
-        private readonly Dictionary<string, Delegate> _sourceHandlers = new Dictionary<string, Delegate>();
+        private readonly Dictionary<string, DelegateInfo> _sourceHandlers = new Dictionary<string, DelegateInfo>();
         private readonly Expression<Func<TSource>> _sourcePropertyExpression;
         private readonly string _sourcePropertyName;
-        private readonly Dictionary<string, Delegate> _targetHandlers = new Dictionary<string, Delegate>();
+        private readonly Dictionary<string, DelegateInfo> _targetHandlers = new Dictionary<string, DelegateInfo>();
         private readonly Expression<Func<TTarget>> _targetPropertyExpression;
         private readonly string _targetPropertyName;
         private WeakAction _onSourceUpdate;
@@ -210,7 +210,8 @@ namespace GalaSoft.MvvmLight.Helpers
 
             _listeners.Clear();
 
-            DetachHandlers();
+            DetachSourceHandlers();
+            DetachTargetHandlers();
         }
 
         /// <summary>
@@ -337,7 +338,27 @@ namespace GalaSoft.MvvmLight.Helpers
 
             // TODO Do we need weak events here?
             EventHandler handler = HandleSourceEvent;
-            _sourceHandlers.Add(eventName, handler);
+
+            var defaultHandlerInfo = _sourceHandlers.Values.FirstOrDefault(i => i.IsDefault);
+
+            if (defaultHandlerInfo != null)
+            {
+                DetachSourceHandlers();
+            }
+
+            var info = new DelegateInfo
+            {
+                Delegate = handler
+            };
+
+            if (_sourceHandlers.ContainsKey(eventName))
+            {
+                _sourceHandlers[eventName] = info;
+            }
+            else
+            {
+                _sourceHandlers.Add(eventName, info);
+            }
 
             ev.AddEventHandler(
                 _propertySource.Target,
@@ -431,7 +452,13 @@ namespace GalaSoft.MvvmLight.Helpers
             switch (mode)
             {
                 case UpdateTriggerMode.LostFocus:
-                    return UpdateSourceTrigger("FocusChanged");
+#if ANDROID
+                    return UpdateSourceTrigger<View.FocusChangeEventArgs>("FocusChange");
+#else
+                    throw new ArgumentException(
+                        "UpdateTriggerMode.LostFocus is only supported in Android at this time",
+                        "mode");
+#endif
 
                 case UpdateTriggerMode.PropertyChanged:
                     return CheckControlSource();
@@ -498,7 +525,27 @@ namespace GalaSoft.MvvmLight.Helpers
 
             // TODO Do we need weak events here?
             EventHandler<TEventArgs> handler = HandleSourceEvent;
-            _sourceHandlers.Add(eventName, handler);
+
+            var defaultHandlerInfo = _sourceHandlers.Values.FirstOrDefault(i => i.IsDefault);
+
+            if (defaultHandlerInfo != null)
+            {
+                DetachSourceHandlers();
+            }
+
+            var info = new DelegateInfo
+            {
+                Delegate = handler
+            };
+
+            if (_sourceHandlers.ContainsKey(eventName))
+            {
+                _sourceHandlers[eventName] = info;
+            }
+            else
+            {
+                _sourceHandlers.Add(eventName, info);
+            }
 
             ev.AddEventHandler(
                 _propertySource.Target,
@@ -592,7 +639,13 @@ namespace GalaSoft.MvvmLight.Helpers
             switch (mode)
             {
                 case UpdateTriggerMode.LostFocus:
-                    return UpdateTargetTrigger("FocusChanged");
+#if ANDROID
+                    return UpdateTargetTrigger<View.FocusChangeEventArgs>("FocusChange");
+#else
+                    throw new ArgumentException(
+                        "UpdateTriggerMode.LostFocus is only supported in Android at this time",
+                        "mode");
+#endif
 
                 case UpdateTriggerMode.PropertyChanged:
                     return CheckControlTarget();
@@ -662,7 +715,27 @@ namespace GalaSoft.MvvmLight.Helpers
 
             // TODO Do we need weak events here?
             EventHandler handler = HandleTargetEvent;
-            _targetHandlers.Add(eventName, handler);
+
+            var defaultHandlerInfo = _targetHandlers.Values.FirstOrDefault(i => i.IsDefault);
+
+            if (defaultHandlerInfo != null)
+            {
+                DetachTargetHandlers();
+            }
+
+            var info = new DelegateInfo
+            {
+                Delegate = handler
+            };
+
+            if (_targetHandlers.ContainsKey(eventName))
+            {
+                _targetHandlers[eventName] = info;
+            }
+            else
+            {
+                _targetHandlers.Add(eventName, info);
+            }
 
             ev.AddEventHandler(
                 _propertyTarget.Target,
@@ -734,7 +807,27 @@ namespace GalaSoft.MvvmLight.Helpers
 
             // TODO Do we need weak events here?
             EventHandler<TEventArgs> handler = HandleTargetEvent;
-            _targetHandlers.Add(eventName, handler);
+
+            var defaultHandlerInfo = _targetHandlers.Values.FirstOrDefault(i => i.IsDefault);
+
+            if (defaultHandlerInfo != null)
+            {
+                DetachTargetHandlers();
+            }
+
+            var info = new DelegateInfo
+            {
+                Delegate = handler
+            };
+
+            if (_targetHandlers.ContainsKey(eventName))
+            {
+                _targetHandlers[eventName] = info;
+            }
+            else
+            {
+                _targetHandlers.Add(eventName, info);
+            }
 
             ev.AddEventHandler(
                 _propertyTarget.Target,
@@ -1068,13 +1161,17 @@ namespace GalaSoft.MvvmLight.Helpers
             var textBox = _propertySource.Target as EditText;
             if (textBox != null)
             {
-                return UpdateSourceTrigger<TextChangedEventArgs>("TextChanged");
+                var binding = UpdateSourceTrigger<TextChangedEventArgs>("TextChanged");
+                binding._sourceHandlers["TextChanged"].IsDefault = true;
+                return binding;
             }
 
             var checkbox = _propertySource.Target as CompoundButton;
             if (checkbox != null)
             {
-                return UpdateSourceTrigger<CompoundButton.CheckedChangeEventArgs>("CheckedChange");
+                var binding = UpdateSourceTrigger<CompoundButton.CheckedChangeEventArgs>("CheckedChange");
+                binding._sourceHandlers["CheckedChange"].IsDefault = true;
+                return binding;
             }
 
             return this;
@@ -1096,13 +1193,17 @@ namespace GalaSoft.MvvmLight.Helpers
             var textBox = _propertyTarget.Target as EditText;
             if (textBox != null)
             {
-                return UpdateTargetTrigger<TextChangedEventArgs>("TextChanged");
+                var binding = UpdateTargetTrigger<TextChangedEventArgs>("TextChanged");
+                binding._targetHandlers["TextChanged"].IsDefault = true;
+                return binding;
             }
 
             var checkbox = _propertyTarget.Target as CompoundButton;
             if (checkbox != null)
             {
-                return UpdateTargetTrigger<CompoundButton.CheckedChangeEventArgs>("CheckedChange");
+                var binding = UpdateTargetTrigger<CompoundButton.CheckedChangeEventArgs>("CheckedChange");
+                binding._targetHandlers["CheckedChange"].IsDefault = true;
+                return binding;
             }
 
             return this;
@@ -1113,7 +1214,7 @@ namespace GalaSoft.MvvmLight.Helpers
 #endif
         }
 
-        private void DetachHandlers()
+        private void DetachSourceHandlers()
         {
             if (_propertySource == null
                 || !_propertySource.IsAlive
@@ -1131,7 +1232,19 @@ namespace GalaSoft.MvvmLight.Helpers
                     return;
                 }
 
-                ev.RemoveEventHandler(_propertySource.Target, _sourceHandlers[eventName]);
+                ev.RemoveEventHandler(_propertySource.Target, _sourceHandlers[eventName].Delegate);
+            }
+
+            _sourceHandlers.Clear();
+        }
+
+        private void DetachTargetHandlers()
+        {
+            if (_propertySource == null
+                || !_propertySource.IsAlive
+                || _propertySource.Target == null)
+            {
+                return;
             }
 
             foreach (var eventName in _targetHandlers.Keys)
@@ -1143,8 +1256,10 @@ namespace GalaSoft.MvvmLight.Helpers
                     return;
                 }
 
-                ev.RemoveEventHandler(_propertyTarget.Target, _targetHandlers[eventName]);
+                ev.RemoveEventHandler(_propertyTarget.Target, _targetHandlers[eventName].Delegate);
             }
+
+            _targetHandlers.Clear();
         }
 
         private TTarget GetSourceValue()
@@ -1380,5 +1495,11 @@ namespace GalaSoft.MvvmLight.Helpers
                 _convertBack = new WeakFunc<TTarget, TSource>(convertBack);
             }
         }
+
+        private class DelegateInfo
+        {
+            public Delegate Delegate;
+            public bool IsDefault;
+        }
     }
 }

GalaSoft.MvvmLight/GalaSoft.MvvmLight.Platform (Android)/Resources/Resource.Designer.cs

@@ -2,7 +2,7 @@
 //------------------------------------------------------------------------------
 // <auto-generated>
 //     This code was generated by a tool.
-//     Runtime Version:4.0.30319.0
+//     Runtime Version:4.0.30319.42000
 //
 //     Changes to this file may cause incorrect behavior and will be lost if
 //     the code is regenerated.

GalaSoft.MvvmLight/GalaSoft.MvvmLight.Platform (NET45)/Properties/AssemblyInfo.cs

@@ -47,4 +47,4 @@ using System.Windows.Markup;
 [assembly:NeutralResourcesLanguage("en-US")]
 
 // BL0035
-[assembly: AssemblyVersion("5.2.0.*")]
+[assembly: AssemblyVersion("5.2.1.*")]

GalaSoft.MvvmLight/GalaSoft.MvvmLight.Platform (iOS)/GalaSoft.MvvmLight.Platform (iOS).csproj

@@ -37,25 +37,25 @@
     <DocumentationFile>bin\iPhone\Release\GalaSoft.MvvmLight.Platform.XML</DocumentationFile>
   </PropertyGroup>
   <ItemGroup>
-    <Compile Include="..\..\..\..\..\..\..\MvvmLight\Source\GalaSoft.MvvmLight\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\Binding.cs">
+    <Compile Include="..\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\Binding.cs">
       <Link>Helpers\Binding.cs</Link>
     </Compile>
-    <Compile Include="..\..\..\..\..\..\..\MvvmLight\Source\GalaSoft.MvvmLight\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\BindingGeneric.cs">
+    <Compile Include="..\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\BindingGeneric.cs">
       <Link>Helpers\BindingGeneric.cs</Link>
     </Compile>
-    <Compile Include="..\..\..\..\..\..\..\MvvmLight\Source\GalaSoft.MvvmLight\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\BindingMode.cs">
+    <Compile Include="..\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\BindingMode.cs">
       <Link>Helpers\BindingMode.cs</Link>
     </Compile>
-    <Compile Include="..\..\..\..\..\..\..\MvvmLight\Source\GalaSoft.MvvmLight\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\Extensions.cs">
+    <Compile Include="..\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\Extensions.cs">
       <Link>Helpers\Extensions.cs</Link>
     </Compile>
-    <Compile Include="..\..\..\..\..\..\..\MvvmLight\Source\GalaSoft.MvvmLight\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\IWeakEventListener.cs">
+    <Compile Include="..\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\IWeakEventListener.cs">
       <Link>Helpers\IWeakEventListener.cs</Link>
     </Compile>
-    <Compile Include="..\..\..\..\..\..\..\MvvmLight\Source\GalaSoft.MvvmLight\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\PropertyChangedEventManager.cs">
+    <Compile Include="..\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\PropertyChangedEventManager.cs">
       <Link>Helpers\PropertyChangedEventManager.cs</Link>
     </Compile>
-    <Compile Include="..\..\..\..\..\..\..\MvvmLight\Source\GalaSoft.MvvmLight\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\UpdateSourceTriggerMode.cs">
+    <Compile Include="..\GalaSoft.MvvmLight.Platform %28Android%29\Helpers\UpdateSourceTriggerMode.cs">
       <Link>Helpers\UpdateSourceTriggerMode.cs</Link>
     </Compile>
     <Compile Include="..\GalaSoft.MvvmLight.Platform %28NET45%29\Properties\AssemblyInfo.cs">