Installer项目是在ABP框架模块模板中，用于自定义模块安装程序的项目。可以使用Installer项目在模块安装期间添加或更新数据库、初始化数据等操作。

以下是一个示例，演示如何在模块安装时向数据库中添加一些种子数据：

1. 创建ModuleInstaller类，实现IModuleInstaller接口，实现Install()方法来添加数据。

public class ModuleInstaller : IModuleInstaller
{
    private readonly IRepository _bookRepository;

    public ModuleInstaller(IRepository bookRepository)
    {
        _bookRepository = bookRepository;
    }

    public void Install()
    {
        AddBooks();
    }

    private void AddBooks()
    {
        _bookRepository.Insert(new Book
        {
            Name = "The Hitchhiker's Guide to the Galaxy",
            Author = "Douglas Adams",
            PublishDate = new DateTime(1981, 10, 12),
            Price = 12.5
        });
        _bookRepository.Insert(new Book
        {
            Name = "The Great Gatsby",
            Author = "F. Scott Fitzgerald",
            PublishDate = new DateTime(1925, 4, 10),
            Price = 10
        });
    }
}

2. 注册ModuleInstaller服务

public override void ConfigureServices(ServiceConfigurationContext context)
{
    context.Services.AddTransient();
}

3. 在模块类的OnApplicationInitialization()方法中通过依赖注入使用ModuleInstaller。

public override void OnApplicationInitialization(ApplicationInitializationContext context)
{
    var moduleInstaller = context.ServiceProvider.GetService();
    moduleInstaller.Install();
}