Hello; I am trying to execute the following code by calling the OpenView() function in the page constructor, inorder to retrieve data from the webservice and fill it up in a picker called servicePicker via an arraylist called services ;
async void OpenView()
{
Uri requestUri = new Uri("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
dynamic dynamicJson = new ExpandoObject();
try
{
dynamicJson.MaintenanceType = "emergency";
dynamicJson.FacilitiesName = "";
dynamicJson.Language = "en";
string jsonData = "";
jsonData = Newtonsoft.Json.JsonConvert.SerializeObject(dynamicJson);
var objClint = new System.Net.Http.HttpClient();
System.Net.Http.HttpResponseMessage respon = await objClint.PostAsync(requestUri, new StringContent(jsonData, System.Text.Encoding.UTF8, "application/json"));
string responJsonText = await respon.Content.ReadAsStringAsync();
RootObject rootObject = JsonConvert.DeserializeObject<RootObject>(responJsonText);
for (int i = 0; i < rootObject.ServiceType.Count; i++)
{
services.Add(rootObject.ServiceType[i].Value);
}
servicePicker.ItemsSource = services;
if (services.Count > 0)
{
Testing.IsRunning = false;
Testing.IsVisible = false;
}
}
catch (Exception ex)
{
DisplayAlert("Test", ex.ToString(), "OK");
}
}
This works totally fine in Android, but crashes in the iOS- ipad . The issue is making me crazy ![:(]( ":(")
. Please help. The exception I get is System.ArgumentException: Value cannot be null.
Here are error details:
System.ArgumentNullException: Value cannot be null. Parameter name: method at System.Linq.Expressions.Expression.Call (System.Linq.Expressions.Expression instance, System.Reflection.MethodInfo method, System.Collections.Generic.IEnumerable1[T] arguments) [0x00111] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.2.0.11/src/mono/external/corefx/src/System.Linq.Expressions/src/System/Linq/Expressions/MethodCallExpression.cs:1239 at System.Linq.Expressions.Expression.Call (System.Linq.Expressions.Expression instance, System.Reflection.MethodInfo method, System.Linq.Expressions.Expression[] arguments) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.2.0.11/src/mono/external/corefx/src/System.Linq.Expressions/src/System/Linq/Expressions/MethodCallExpression.cs:1046 at System.Linq.Expressions.Expression.Call (System.Reflection.MethodInfo method, System.Linq.Expressions.Expression[] arguments) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.2.0.11/src/mono/external/corefx/src/System.Linq.Expressions/src/System/Linq/Expressions/MethodCallExpression.cs:1001 at System.Dynamic.ExpandoObject+MetaExpando.BindSetMember (System.Dynamic.SetMemberBinder binder, System.Dynamic.DynamicMetaObject value) [0x00033] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.2.0.11/src/mono/external/corefx/src/System.Linq.Expressions/src/System/Dynamic/ExpandoObject.cs:863 at System.Dynamic.SetMemberBinder.Bind (System.Dynamic.DynamicMetaObject target, System.Dynamic.DynamicMetaObject[] args) [0x00035] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.2.0.11/src/mono/external/corefx/src/System.Linq.Expressions/src/System/Dynamic/SetMemberBinder.cs:57 at System.Dynamic.DynamicMetaObjectBinder.Bind (System.Object[] args, System.Collections.ObjectModel.ReadOnlyCollection1[T] parameters, System.Linq.Expressions.LabelTarget returnLabel) [0x000c6] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.2.0.11/src/mono/external/corefx/src/System.Linq.Expressions/src/System/Dynamic/DynamicMetaObjectBinder.cs:90 at System.Runtime.CompilerServices.CallSiteBinder.BindCore[T] (System.Runtime.CompilerServices.CallSite1[T] site, System.Object[] args) [0x00019] in <773264786149499a986a13db6a7d46fe>:0 at System.Runtime.CompilerServices.CallSiteOps.Bind[T] (System.Runtime.CompilerServices.CallSiteBinder binder, System.Runtime.CompilerServices.CallSite1[T] site, System.Object[] args) [0x00000] in <773264786149499a986a13db6a7d46fe>:0 at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,object,object[],System.Exception&) at System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00032] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.2.0.11/src/mono/mcs/class/corlib/System.Reflection/MonoMethod.cs:305 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.2.0.11/src/mono/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:151 at System.Linq.Expressions.Interpreter.ExceptionHelpers.UnwrapAndRethrow (System.Reflection.TargetInvocationException exception) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.2.0.11/src/mono/external/corefx/src/System.Linq.Expressions/src/System/Linq/Expressions/Interpreter/Utilities.cs:174 at System.Linq.Expressions.Interpreter.MethodInfoCallInstruction.Run (System.Linq.Expressions.Interpreter.InterpretedFrame frame) [0x00035] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.2.0.11/src/mono/external/corefx/src/System.Linq.Expressions/src/System/Linq/Expressions/Interpreter/CallInstruction.cs:333 at System.Linq.Expressions.Interpreter.Interpreter.Run (System.Linq.Expressions.Interpreter.InterpretedFrame frame) [0x00015] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.2.0.11/src/mono/external/corefx/src/System.Linq.Expressions/src/System/Linq/Expressions/Interpreter/Interpreter.cs:63 at System.Linq.Expressions.Interpreter.LightLambda.Run3[T0,T1,T2,TRet] (T0 arg0, T1 arg1, T2 arg2) [0x00038] in <773264786149499a986a13db6a7d46fe>:0 at App1.SnapFix+d__31.MoveNext () [0x00031] in C:\Users\mjehangir\source\repos\App1\App1\App1\SnapFix.xaml.cs:199
\git\Xam.Forms.Mvx\CoolBeans\CoolBeans\Pages\DetailedMoviePage.cs 101 13 CoolBeans
. Please help. The exception I get is System.ArgumentException: Value cannot be null.