.NET应用连接MongoDB遇System.MissingMethodException问题求助

错误信息 #

通过Swagger测试路由时抛出：

System.MissingMethodException: Method not found: 'MongoDB.Bson.GuidRepresentationMode MongoDB.Bson.BsonDefaults.get_GuidRepresentationMode()'.
at MongoDB.Driver.MongoUrlBuilder..ctor()
at MongoDB.Driver.MongoUrlBuilder..ctor(String url)
at Microsoft.EntityFrameworkCore.MongoOptionsExtension.SanitizeConnectionStringForLogging(String connectionString)
at Microsoft.EntityFrameworkCore.MongoOptionsExtension.WithConnectionString(String connectionString)
at Microsoft.EntityFrameworkCore.MongoDbContextOptionsExtensions.UseMongoDB(DbContextOptionsBuilder optionsBuilder, String connectionString, String databaseName, Action1 optionsAction)

运行应用时终端额外提示：

The type 'IMongoClient' is defined in an assembly that is not referenced. You must add a reference to assembly 'MongoDB.Driver, Version=2.25.0.0, Culture=neutral, PublicKeyToken=null'. [/Users/rakibulb/Documents/ComputerScience/PortfolioProjects/Web/book-management/backend/backend.csproj]

我希望通过在Program.cs中添加一次性测试条目到数据库来验证连接，以下是相关代码文件：

相关代码文件 #

Program.cs #

using backend.Data;
using Microsoft.EntityFrameworkCore;
using backend.Models;
using MongoDB.Driver;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddControllersWithViews();

var mongoDBSettings = builder.Configuration.GetSection("MongoDBSettings").Get<MongoDBSettings>() 
    ?? throw new InvalidOperationException("MongoDBSettings section is not configured");

builder.Services.Configure<MongoDBSettings>(builder.Configuration.GetSection("MongoDBSettings"));

builder.Services.AddDbContext<ApplicationDBContext>(options => 
    options.UseMongoDB(mongoDBSettings.AtlasURI, mongoDBSettings.DatabaseName));

builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();


var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

app.MapPost("/api/test-book", async (ApplicationDBContext context) =>
{
    try
    {
        var testBook = new Book
        {
            Title = "Test Book",
            Author = "Test Author",
            Pages = 100
        };

        context.Books.Add(testBook);
        await context.SaveChangesAsync();

        return Results.Ok(new { message = "Test book added successfully", book = testBook });
    }
    catch (Exception ex)
    {
        return Results.BadRequest(new { message = $"Error adding book: {ex.Message}" });
    }
});

// You can also add a GET endpoint to verify the book was added
app.MapGet("/api/test-book", async (ApplicationDBContext context) =>
{
    var books = await context.Books.ToListAsync();
    return Results.Ok(books);
});

app.Run();

// MongoDB password : 6F1uj59S9WzSkbfK

backend.csproj #

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.4" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="8.0.4">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="8.0.4">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
    <PackageReference Include="MongoDB.Bson" Version="3.0.0" />
    <PackageReference Include="MongoDB.Driver" Version="3.0.0" />
    <PackageReference Include="MongoDB.Driver.Core" Version="2.30.0" />
    <PackageReference Include="MongoDB.EntityFrameworkCore" Version="8.0.0" />
    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.6.2" />
  </ItemGroup>

</Project>

解决方案 #

1. 统一MongoDB相关包版本 #

问题根源是MongoDB各组件版本不兼容：MongoDB.Bson/MongoDB.Driver用了3.0.0，MongoDB.Driver.Core是2.30.0，而MongoDB.EntityFrameworkCore 8.0.0要求MongoDB驱动版本至少为2.25.0。修改backend.csproj中的包引用，统一所有MongoDB相关包的版本：

<PackageReference Include="MongoDB.Bson" Version="2.25.0" />
<PackageReference Include="MongoDB.Driver" Version="2.25.0" />
<PackageReference Include="MongoDB.Driver.Core" Version="2.25.0" />
<PackageReference Include="MongoDB.EntityFrameworkCore" Version="8.0.0" />

2. 清理重建项目 #

• 删除项目目录下的bin和obj文件夹
• 执行命令 dotnet restore 恢复依赖
• 执行命令 dotnet build 重新构建项目

3. 一次性测试数据插入优化 #

如果要在应用启动时仅执行一次测试数据插入，无需通过API接口，可调整Program.cs：

var app = builder.Build();

// 启动前添加一次性测试数据
using (var scope = app.Services.CreateScope())
{
    var context = scope.ServiceProvider.GetRequiredService<ApplicationDBContext>();
    // 避免重复插入
    if (!await context.Books.AnyAsync(b => b.Title == "Test Book"))
    {
        var testBook = new Book
        {
            Title = "Test Book",
            Author = "Test Author",
            Pages = 100
        };
        context.Books.Add(testBook);
        await context.SaveChangesAsync();
        Console.WriteLine("Test book added successfully");
    }
}

// 后续中间件配置...

内容的提问来源于stack exchange，提问作者RakibulB