I have Xamarin Forms app supporting iOS and Android. It works correctly on Android in release mode. On iOS, it doesn't work in release mode but works in Debug mode. It's crashing when clicked on a button which calls few functions. I have attached error log below. The strange thing is, it works on Simulator in release mode.
Error log:
Incident Identifier: 391C564C-028D-4084-BC4A-21ED49BB1F25
CrashReporter Key: 30B4418D-AA04-4575-97A3-97A9F491C62D
Hardware Model: iPhone7,2
Process: TestApp.iOS [600]
Path: /var/containers/Bundle/Application/7F4E5392-9BEA-4578-9E23-02112B61EB96/TestApp.iOS.app/TestApp.iOS
Identifier: uk.co.company.testapp
Version: 0.0.1 (1.0)
Code Type: ARM-64
Parent Process: ??? [1]
Date/Time: 2018-01-22T13:02:31Z
Launch Time: 2018-01-22T13:02:23Z
OS Version: iPhone OS 9.3.2 (13F69)
Report Version: 104-Xamarin
Exception Type: SIGABRT
Exception Codes: #0 at 0x180da811c
Crashed Thread: 0
Application Specific Information:
*** Terminating app due to uncaught exception 'System.ArgumentNullException', reason: 'System.ArgumentNullException: Value cannot be null.'
Xamarin Exception Stack:
Parameter name: method
at System.Linq.Expressions.Expression.Call (System.Linq.Expressions.Expression instance, System.Reflection.MethodInfo method, System.Collections.Generic.IEnumerable`1[T] arguments) [0x00111] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.6.1.3/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/11.6.1.3/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/11.6.1.3/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/11.6.1.3/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/11.6.1.3/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.ReadOnlyCollection`1[T] parameters, System.Linq.Expressions.LabelTarget returnLabel) [0x000c6] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.6.1.3/src/mono/external/corefx/src/System.Linq.Expressions/src/System/Dynamic/DynamicMetaObjectBinder.cs:90
at System.Runtime.CompilerServices.CallSiteBinder.BindCore[T] (System.Runtime.CompilerServices.CallSite`1[T] site, System.Object[] args) [0x00019] in <8bc31b0df50a4d32b3f1d5af764165ad>:0
at System.Runtime.CompilerServices.CallSiteOps.Bind[T] (System.Runtime.CompilerServices.CallSiteBinder binder, System.Runtime.CompilerServices.CallSite`1[T] site, System.Object[] args) [0x00000] in <8bc31b0df50a4d32b3f1d5af764165ad>: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/11.6.1.3/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/11.6.1.3/src/mono/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:152
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Exception source) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.6.1.3/src/mono/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:156
at System.Linq.Expressions.Interpreter.ExceptionHelpers.UnwrapAndRethrow (System.Reflection.TargetInvocationException exception) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.6.1.3/src/mono/external/corefx/src/System.Linq.Expressions/src/System/Linq/Expressions/Interpreter/Utilities.cs:172
at System.Linq.Expressions.Interpreter.MethodInfoCallInstruction.Run (System.Linq.Expressions.Interpreter.InterpretedFrame frame) [0x00035] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.6.1.3/src/mono/external/corefx/src/System.Linq.Expressions/src/System/Linq/Expressions/Interpreter/CallInstruction.cs:327
at System.Linq.Expressions.Interpreter.Interpreter.Run (System.Linq.Expressions.Interpreter.InterpretedFrame frame) [0x00015] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.6.1.3/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 <8bc31b0df50a4d32b3f1d5af764165ad>:0
at TestApp.LoginPage+<onLoginClicked>d__1.MoveNext () [0x00205] in <42b3f78eef3b4fad8ca201e1a739e68b>:0
--- 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/11.6.1.3/src/mono/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:152
at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0 (System.Object state) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.6.1.3/src/mono/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1018
at UIKit.UIKitSynchronizationContext+<Post>c__AnonStorey0.<>m__0 () [0x00000] in /Users/builder/data/lanes/5665/f70a1348/source/xamarin-macios/src/UIKit/UIKitSynchronizationContext.cs:24
at Foundation.NSAsyncActionDispatcher.Apply () [0x00000] in /Users/builder/data/lanes/5665/f70a1348/source/xamarin-macios/src/Foundation/NSAction.cs:163
at (wrapper managed-to-native) UIKit.UIApplication:UIApplicationMain (int,string[],intptr,intptr)
at UIKit.UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate) [0x00005] in /Users/builder/data/lanes/5665/f70a1348/source/xamarin-macios/src/UIKit/UIApplication.cs:79
at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x00038] in /Users/builder/data/lanes/5665/f70a1348/source/xamarin-macios/src/UIKit/UIApplication.cs:63
at TestApp.iOS.Application.Main (System.String[] args) [0x00000] in <52e34ea9026340479b8dc6a53c640f1e>:0
EDIT: I have an interesting finding. I'm calling onLoginClicked function on the touch of a button, which then calls PostData function which makes a REST Call to send data to the server. Whenever the PostData function is called, app crashes.
If I move all the code from PostData function to onLoginClicked function, it works!
Please find additional information below:
The app crashes in onLoginClicked method at a line where PostData function is called i.e.
string responseData = await PostData(user, "auth/login");
When I tried putting some alerts in PostData function to see what point it reaches but found that it doesn't even hit the very first line in that method. This is very strange.
Code:
async void onLoginClicked(object sender, System.EventArgs e)
{
string error = "";
if (txtEmail.Text == null || txtEmail.Text == "")
{
error += Constants.ERR_BLANK_EMAIL + "\r\n";
}
else if (txtEmail.Text.Length < 6)
{
error += Constants.ERR_EMAIL_LENGTH + "\r\n";
}
else if (!Common.isEmailValid(txtEmail.Text))
{
error += Constants.ERR_EMAIL_VALIDATION + "\r\n";
}
if (txtPassword.Text == null || txtPassword.Text == "")
{
error += Constants.ERR_BLANK_PASSWORD;
}
if (error != "")
{
lblError.Text = error;
errorContainer.IsVisible = true;
return;
}
else
{
errorContainer.IsVisible = false;
}
if (CrossConnectivity.Current.IsConnected)
{
var loadingPage = new LoadingPage();
await Navigation.PushPopupAsync(loadingPage);
var device_token = App.channelId;
dynamic user = new System.Dynamic.ExpandoObject();
user.email = txtEmail.Text;
user.user_type = "b2b";
user.device_token = device_token;
user.password = txtPassword.Text;
if (Device.RuntimePlatform == Device.iOS)
{
user.device_type = "ios";
}else{
user.device_type = "android";
}
string responseData = await PostData(user, "auth/login");
dynamic responseObj = JObject.Parse(responseData);
if (responseObj["error_code"].Value == 0)
{
var data = responseObj["data"];
Constants.user = Common.GetUserObject(data.ToString());
Helpers.Settings.Password = "" + txtPassword.Text;
Helpers.Settings.UserId = "" + Constants.user.userId;
Helpers.Settings.accessToken = ""+data.access_token;
Helpers.Settings.Email = "" + txtEmail.Text;
var outletResp = responseObj["outlet_details"];
var outlet_count = outletResp.Count;
if(outlet_count>0)
{
Constants.outlets = new List<Outlet>();
foreach(var store in outletResp){
Outlet shop = new Outlet();
shop.access_token = store["access_token"];
shop.email = store["email"];
shop.user_id = store["id"];
shop.master_id = store["master_id"];
shop.outlet_id = store["outlet_id"];
shop.post_code = store["post_code"];
shop.profile_pic = store["profile_pic"];
shop.retailer_id = store["retailer_id"];
shop.retailer_image = store["retailer_image"];
shop.store_name = store["store_name"];
shop.tutorial_pricing_tool = int.Parse(""+store["tutorial_pricing_tool"]);
Constants.outlets.Add(shop);
}
}
var isPinSet = Helpers.Settings.PinSet;
await Navigation.RemovePopupPageAsync(loadingPage);
if (responseObj.data.pin==0 || !isPinSet){
App.Current.MainPage = new NavigationPage(new SetPinPage(false));
}
else{
App.Current.MainPage = new NavigationPage(new StoreListPage());
}
}
else
{
await Navigation.RemovePopupPageAsync(loadingPage);
if (responseObj["error_code"].Value == 1)
lblError.Text = responseObj["error"];
else
lblError.Text = responseObj["message"];
errorContainer.IsVisible = true;
}
}
else
{
await DisplayAlert(Constants.APP_TITLE, "Please check your internet connection.", "OK");
}
}
async public Task<string> PostData(System.Dynamic.ExpandoObject args, string actionUrl)
{
string responseData = "";
HttpClient client = new HttpClient();
client.MaxResponseContentBufferSize = 256000;
var param = Constants.JWT ? GetJWTToken(args, actionUrl) : JsonConvert.SerializeObject(args);
var content = new StringContent(param, Encoding.UTF8, "application/json");
client.DefaultRequestHeaders.Add("Authorization", param);
client.DefaultRequestHeaders.Add("X-Device-Type", "android");
client.DefaultRequestHeaders.Add("X-APP-Type", "b2b");
client.DefaultRequestHeaders.Add("X-APP-Platform", "xamarin");
HttpResponseMessage response = null;
response = await client.PostAsync(Constants.BaseUrl + actionUrl, content);
if (response.IsSuccessStatusCode)
{
response.EnsureSuccessStatusCode();
}
responseData = await response.Content.ReadAsStringAsync();
if (Constants.JWT)
{
var resp = JObject.Parse(responseData);
var respToken = resp["token"];
var rtokenStr = respToken.ToObject<String>();
var respPayloadStr = rtokenStr.Split('.');
byte[] data = JWTLibrary.Converter.Base64UrlDecode(respPayloadStr[1]);
responseData = JWTLibrary.Converter.GetStringFromBytes(data);
}
return responseData;
}
private string GetJWTToken(System.Dynamic.ExpandoObject args, string actionUrl)
{
var dt = DateTime.Now;
var ticks = dt.Ticks;
var currentSec = ticks / TimeSpan.TicksPerSecond;
var newEndTime = currentSec + 60;
Object payload = new Dictionary<string, object>()
{
{ "iat", currentSec },
{ "nbf", currentSec },
{ "exp", newEndTime },
{ "iss", actionUrl },
{ "jti", "" },
{ "bat_data", args }
};
var secret_key = "key";
dynamic n_header = new System.Dynamic.ExpandoObject();
n_header.typ = "jwt";
n_header.alg = "HS256";
byte[] headerBytes = JWTLibrary.Converter.GetBytesFromString(JsonConvert.SerializeObject(n_header));
byte[] payloadBytes = JWTLibrary.Converter.GetBytesFromString(JsonConvert.SerializeObject(payload));
var enc_header = JWTLibrary.Converter.Base64UrlEncode(headerBytes);
var enc_payload = JWTLibrary.Converter.Base64UrlEncode(payloadBytes);
string jwt_token = enc_header + "." + enc_payload;
var sh_h256 = JWTLibrary.Converter.CreateToken(jwt_token, secret_key);
var jwt_enc_signature = JWTLibrary.Converter.Base64UrlEncode(sh_h256);
jwt_token = jwt_token + "." + jwt_enc_signature;
return jwt_token;
}
I'm afraid the problem was caused by dynamic keyword.
The
DynamicMethodclass is a part of the set of runtime code generation features that reside withSystem.Reflection.Emit. However,System.Reflection.EmitAPI is not available in iOS.
Detail refer to Why can’t I use the “dynamic” C# keyword in Xamarin.iOS?