我怎么知道 automapper 是否已经初始化？

Question

Is there a way to know if automapper has already been initialized? For example:

AutoMapper.Mapper.IsInitialized(); // would return false
AutoMapper.Mapper.Initialize( /*options here*/ );
AutoMapper.Mapper.IsInitialized(); // would return true

Thanks!

Answer 1

You could call Mapper.Reset(); before initializing your mapper. I do this when initializing my unit test classes:

[ClassInitialize]
public static void ClassInitializer(TestContext context)
{
    Mapper.Reset();
    AutoMapperDataConfig.Configure();            
}

Answer 2

Try to use:

AutoMapper.Mapper.Configuration.AssertConfigurationIsValid();

It throws System.InvalidOperationException...Mapper not initialized. Call Initialize with appropriate configuration. System.InvalidOperationException...Mapper not initialized. Call Initialize with appropriate configuration. .

Answer 3

In our particular case, we had multiple unit tests competing for the same instance of AutoMapper. Even if we used the Reset() method, it threw the error that it was already initialized. We solved the problem with a singleton instance that is inherited by each unit test class in our tests project.

public class UnitTestsCommon
{
    public static IMapper AutoMapperInstance = null;

    public UnitTestsCommon()
    {
        if(UnitTestsCommon.AutoMapperInstance == null){       
            Mapper.Initialize(AutoMapperConfiguration.BootstrapMapperConfiguration);
            AutoMapperInstance = Mapper.Instance;
        }
    }
}

Answer 4

Basically, you are trying to configure the Mapper at multiple places in your code, as I understand, you are trying to fix the issue by centralizing the configuration.

This issue could be resolved also through using the Instance API, where multiple (one per instance) configurations are possible (for plugin or more separated architectures) http://docs.automapper.org/en/stable/Static-and-Instance-API.html

Answer 5

You could also wrap your Initialization in a Try/Catch. This catches and squashes any error.

private void InitializeMapper()
    {
        try
        {
            Mapper.Initialize(cfg =>
            {
                cfg.AddProfile<MyProfile>();
            });
        }
        catch
        {

        }
    }