更新

app/Http/Controllers/Api/UploadController.php

@@ -12,7 +12,7 @@ class UploadController extends Controller
     {
         try {
             //获取上传的文件
-            $file = $request->file('file');
+            $file = $request->file();
             return response()->json(['data' => $file]);
             //获取上传图片的临时地址
             $tmppath = $file->getRealPath();