protected override void OnMessage(MessageEventArgs e)
{
if (e.Data == null)
{
return;
}
if (e.Data != null)
{
FlutnetMessage request;
try
{
request = JsonConvert.DeserializeObject <FlutnetMessage>(e.Data, FlutterInterop.JsonSerializerSettings);
}
catch (Exception)
{
// ignore invalid messages
return;
}
FlutnetRuntime.OperationInfo operation;
try
{
operation = FlutnetRuntime.GetOperation(request.MethodInfo.Instance, request.MethodInfo.Operation);
}
catch (Exception)
{
FlutnetException error = new FlutnetException(FlutnetErrorCode.OperationNotImplemented);
SendError(request.MethodInfo, error);
return;
}
if (operation.Parameters.Length != request.Arguments.Count)
{
FlutnetException error = new FlutnetException(FlutnetErrorCode.OperationArgumentCountMismatch);
SendError(request.MethodInfo, error);
return;
}
object[] arguments = new object[operation.Parameters.Length];
try
{
for (int i = 0; i < operation.Parameters.Length; i++)
{
ParameterInfo param = operation.Parameters[i];
Type paramType = param.IsOut || param.ParameterType.IsByRef
? param.ParameterType.GetElementType()
: param.ParameterType;
string paramName = param.Name.FirstCharUpper();
object value;
if (request.Arguments.ContainsKey(paramName))
{
object argumentValue = request.Arguments[paramName];
if (argumentValue == null)
{
value = null;
}
else if (argumentValue.GetType() == paramType)
{
value = argumentValue;
}
else if (argumentValue is string && paramType != null && paramType.IsEnum)
{
// Handle enums: remove double quotes from "enumName"
string enumString = (argumentValue as string);
value = Enum.Parse(paramType, enumString);
}
else if (paramType != null && argumentValue.GetType().IsPrimitive&& paramType.IsPrimitive)
{
value = Convert.ChangeType(argumentValue, paramType);
}
else
{
JObject jobj = JObject.FromObject(argumentValue);
value = jobj.ToObject(paramType);
}
}
else if (param.HasDefaultValue)
{
value = param.DefaultValue;
}
else
{
FlutnetException error = new FlutnetException(FlutnetErrorCode.InvalidOperationArguments);
SendError(request.MethodInfo, error);
return;
}
arguments[i] = value;
}
}
catch (Exception)
{
FlutnetException error = new FlutnetException(FlutnetErrorCode.OperationArgumentParsingError);
SendError(request.MethodInfo, error);
return;
}
PlatformOperationResult result = PlatformOperationRunner.Run(operation, arguments);
if (result.Error != null)
{
if (result.Error is PlatformOperationException flutterException)
{
SendError(request.MethodInfo, flutterException);
}
else
{
//In case of an unhandled exception, send to Flutter a verbose error message for better diagnostic
FlutnetException error = new FlutnetException(FlutnetErrorCode.OperationFailed, result.Error.ToStringCleared(), result.Error);
SendError(request.MethodInfo, error);
}
}
else
{
SendResult(request.MethodInfo, result.Result);
}
}
}
private void BackgroundHandleMethodCall(FlutnetMethodInfo methodInfo, FlutterMethodCall call)
{
FlutnetRuntime.OperationInfo operation;
try
{
operation = FlutnetRuntime.GetOperation(methodInfo.Instance, methodInfo.Operation);
}
catch (Exception)
{
SendError(methodInfo, new FlutnetException(FlutnetErrorCode.OperationNotImplemented));
return;
}
NSDictionary dartArguments = call.Arguments as NSDictionary;
if (operation.Parameters.Length > 0 && dartArguments == null)
{
SendError(methodInfo, new FlutnetException(FlutnetErrorCode.OperationArgumentCountMismatch));
return;
}
object[] arguments = new object[operation.Parameters.Length];
try
{
for (int i = 0; i < operation.Parameters.Length; i++)
{
ParameterInfo param = operation.Parameters[i];
Type paramType = param.IsOut || param.ParameterType.IsByRef
? param.ParameterType.GetElementType()
: param.ParameterType;
NSString paramName = new NSString(param.Name.FirstCharUpper());
object value;
if (dartArguments.ContainsKey(paramName))
{
NSObject argumentValue = dartArguments[paramName];
NSString serializedArg = (NSString)argumentValue;
// Deserialize the arg value
value = JsonConvert.DeserializeObject(serializedArg, paramType, FlutterInterop.JsonSerializerSettings);
}
else if (param.HasDefaultValue)
{
value = param.DefaultValue;
}
else
{
SendError(methodInfo, new FlutnetException(FlutnetErrorCode.InvalidOperationArguments));
return;
}
arguments[i] = value;
}
}
catch (Exception)
{
SendError(methodInfo, new FlutnetException(FlutnetErrorCode.OperationArgumentParsingError));
return;
}
PlatformOperationResult result = PlatformOperationRunner.Run(operation, arguments);
if (result.Error != null)
{
if (result.Error is PlatformOperationException flutterException)
{
SendError(methodInfo, flutterException);
}
else
{
//In case of an unhandled exception, send to Flutter a verbose error message for better diagnostic
FlutnetException error = new FlutnetException(FlutnetErrorCode.OperationFailed, result.Error.ToStringCleared(), result.Error);
SendError(methodInfo, error);
}
}
else
{
SendResult(methodInfo, result.Result);
}
}