1. 确保在服务器端配置了正确的文件上传路由。
2. 在客户端的Mutation中，确保'file”参数的类型设置为“Upload”类型。
3. 设置正确的请求头文件，包括Content-Type和Authorization。
4. 确保上传文件的大小没有超过服务器的限制。

以下是示例代码：

服务器端配置：

const upload = require('multer')({ dest: 'uploads/' })

app.post('/upload', upload.single('file'), (req, res) => { console.log(req.file) res.send('File uploaded successfully') })

客户端Mutation：

const UPLOAD_FILE_MUTATION = gql mutation UploadFileMutation($file: Upload!) { uploadFile(file: $file) { url } }

请求头文件设置：

const httpLink = createHttpLink({ uri: process.env.API_ENDPOINT, headers: { 'Content-Type': 'application/json', Authorization: Bearer ${process.env.TOKEN}, }, })

文件大小限制：

const uploadLink = new ApolloLink((operation, forward) => { if (operation.operationName === 'UploadFileMutation') { const files = Array.from(operation.variables.file || []) const size = files.reduce((acc, file) => acc + file.size, 0) if (size > MAX_FILE_SIZE) { throw new Error(Files must be ${MAX_FILE_SIZE} bytes or less) } } return forward(operation) }).concat(httpLink)