# rpc 错误：代码 = Unimplemented 描述 = 未知方法 SayHello

- **ID:** `go/grpc-unimplemented-method`
- **领域:** go
- **类别:** module_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

服务器未实现请求的 RPC 方法，可能是由于 proto 生成过时。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 1.56.x | active | — | — |
| 1.57.x | active | — | — |

## 解决方案

1. **** (95% 成功率)
   ```
   protoc --go_out=. --go-grpc_out=. *.proto; go build -o server server.go
   ```
2. **** (90% 成功率)
   ```
   if err := pb.RegisterGreeterServer(s, &server{}); err != nil { log.Fatal(err) }
   ```
3. **** (85% 成功率)
   ```
   Ensure method name matches exactly: client.SayHello(ctx, req)
   ```

## 无效尝试

- **Trying other methods that also don't exist.** — All methods may be unimplemented. (80% 失败率)
- **Using nil response from failed call.** — Nil pointer dereference. (90% 失败率)
- **Assuming the method was removed.** — May still be needed. (60% 失败率)