我有一个处理PDF的检索和合并的服务项目,还有一个具有上下文和模型的存储库项目。
最初,我们使用具有功能性的API来创建它,并认为对于简单的应用程序来说这会产生过多的开销,并将逻辑放入简单的服务中并对其进行引用。
我正在尝试从Blazor页面调用服务中的方法,我已经在启动文件中注册了Service,并在页面上为DI注入了Services,但现在我收到以下错误。具体而言,是与服务所引用的存储库中的上下文有关。
我一直在尝试注入,在启动文件中添加了服务,并且各种格式更改都无济于事。
在启动文件中配置服务:
public void ConfigureServices(IServiceCollection services)
{
services.AddTransient<IBOLService, BOLService>();
services.AddTransient<IPDFService, PDFService>();
services.AddRazorPages();
services.AddServerSideBlazor();
services.AddHttpClient();
services.AddDbContext<CoviaDevIntegrationControlContext>(options =>
options.UseSqlServer(Configuration.GetConnectionString("IntegrationControl")));
}
剃须刀主页面的注入和使用摘录:
@page "/download"
@using LAS.BOLDownloader.Models
@using System.IO;
@using System.Net.Http;
@using System.Net.Http.Headers
@using Microsoft.AspNetCore.Components.Web
@using LAS.BOLDownloader.Data;
@using BOL.Data;
@using BOL.Services;
@inject IJSRuntime js
@inject Microsoft.JSInterop.IJSRuntime JS
@inject CoviaDevIntegrationControlContext IntegrationControlContext
@inject IHttpClientFactory clientFactory
@inject IBOLService _bolService
@inject IPDFService _pdfService
服务类别:
public class BOLService : IBOLService
{
private CoviaDevIntegrationControlContext _context;
public BOLService(CoviaDevIntegrationControlContext context)
{
_context = context;
}
public async Task<byte[][]> GetDocuments(string searchString, string IdType, int SiteId)
{
var bolNumbers = searchString.Split(',');
if (IdType == "BolNumber")
{
return await _context.Las2cpBolstaging.Where(o => bolNumbers.Contains(o.BolNumber.ToString()) && o.PlantId == SiteId).Select(o => o.BolDoc).ToArrayAsync();
}
else if (IdType == "ShipmentId")
{
return await _context.Las2cpBolstaging.Where(o => bolNumbers.Contains(o.BolNumber.ToString()) && o.PlantId == SiteId).Select(o => o.BolDoc).ToArrayAsync();
}
else
{
return null;
}
}
存储库中的上下文:
public partial class CoviaDevIntegrationControlContext : DbContext
{
public CoviaDevIntegrationControlContext()
{
}
public CoviaDevIntegrationControlContext(DbContextOptions<CoviaDevIntegrationControlContext> options)
: base(options)
{
}
public virtual DbSet<Las2cpBoldocStaging> Las2cpBoldocStaging { get; set; }
public virtual DbSet<Las2cpBolstaging> Las2cpBolstaging { get; set; }
public virtual DbSet<LasBols> LasBols { get; set; }
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
if (!optionsBuilder.IsConfigured)
{
optionsBuilder.UseSqlServer("Server=dev-sql1;Database=Covia.Dev.IntegrationControl;Trusted_Connection=True;MultipleActiveResultSets=True;");
}
}
使用注入的功能:
protected async Task GetBOL(int SiteId, string IdType)
{
var client = clientFactory.CreateClient();
si.SiteId = SiteId;
si.IdType = IdType;
try
{
Process bp = new BOLProcess( _bolService, _pdfService);
var bolPdf = bp.GetBOLs(si.searchString, si.IdType, si.SiteId).Result;
bolResultsList = bp.GetResults(si.searchString, si.IdType, si.SiteId).Result;
if (bolPdf != null && bolPdf.Length > 0)
{
await FileUtil.SaveAs(js, "BOLDocument.pdf", bolPdf);
}
}
catch (Exception ex)
{
var error = ex.Message;
}
}
InvalidOperationException:验证服务时出错描述符'ServiceType:BOL.Services.IBOLService寿命:瞬态ImplementationType:BOL.Services.BOLService':无法解析类型服务“ BOL.Repository.Models.CoviaDevIntegrationControlContext”时尝试激活“ BOL.Services.BOLService”。
内部异常InvalidOperationException:无法解析服务用于类型'BOL.Repository.Models.CoviaDevIntegrationControlContext'尝试激活“ BOL.Services.BOLService”时。
尝试此补救方法:
由于DBContext受作用域限制,所以在services.AddTransient<IBOLService, BOLService>();
中使用AddScoped而不是AddTransient
如果不是问题,请尝试放置
services.AddTransient<IBOLService, BOLService>();
services.AddTransient<IPDFService, PDFService>();
在ConfigureServices的末尾,而不是在开头...
您还应该提供baseUri,因为这是SPA应用程序,对:
services.AddHttpClient<IXXXHttpClient, XXXHttpClient>(config =>
config.BaseAddress = new Uri(<uri string>));
希望这有帮助...