As a developer, encountering errors is a common occurrence. One of the most common errors is the "Missing Type Map Configuration or Unsupported Mapping Error." This error occurs when trying to map a data type that does not have a corresponding map configuration.
In this guide, we will explain what this error means and provide a step-by-step solution to resolve it.
What is Missing Type Map Configuration or Unsupported Mapping Error?
The Missing Type Map Configuration or Unsupported Mapping Error occurs when trying to map a data type that does not have a corresponding map configuration. This error can occur when using AutoMapper, a popular object-to-object mapping library for .NET.
When attempting to map a data type that is not registered in the configuration, AutoMapper throws an exception with the following message:
AutoMapper.AutoMapperMappingException: Missing type map configuration or unsupported mapping.
This error can be frustrating for developers, but it is easily resolved.
Step-by-Step Solution
To resolve the Missing Type Map Configuration or Unsupported Mapping Error, follow these steps:
Add the missing type to the configuration.
Mapper.Initialize(cfg =>
{
cfg.CreateMap<SourceType, DestinationType>();
cfg.CreateMap<MissingType, DestinationType>();
});
In the above example, MissingType is the data type that was not registered in the configuration. By adding it to the configuration, AutoMapper can map the data type without throwing an exception.
Update the mapping code to include the missing type.
var source = new SourceType();
var destination = Mapper.Map<DestinationType>(source);
var missing = Mapper.Map<MissingType>(source); // map missing type
In the above example, we updated the mapping code to include the missing type. Now, AutoMapper can map the missing type without throwing an exception.
Test the code to ensure the error is resolved.
After adding the missing type to the configuration and updating the mapping code, test the code to ensure the error is resolved.
FAQ
Q1: What causes the Missing Type Map Configuration or Unsupported Mapping Error?
The error occurs when trying to map a data type that does not have a corresponding map configuration.
Q2: How can I fix the Missing Type Map Configuration or Unsupported Mapping Error?
To resolve the error, add the missing type to the configuration and update the mapping code to include the missing type.
Q3: What is AutoMapper?
AutoMapper is a popular object-to-object mapping library for .NET.
Q4: Is the Missing Type Map Configuration or Unsupported Mapping Error a common error?
Yes, it is a common error that developers encounter when using AutoMapper.
Q5: Can I prevent the Missing Type Map Configuration or Unsupported Mapping Error?
Yes, you can prevent the error by ensuring that all data types are registered in the configuration before attempting to map them.