我是 Flutter iOS 开发的新手 我已经升级了我的 Flutter 版本，然后在我的应用程序无法构建 iOS 应用程序后我得到了我在下面提到的这个异常，请帮助我。在此之前它工作正常我应该重新安装 flutter 或任何其他想法意味着很多，提前致谢

Xcode build done.                                           10.7s
Failed to build iOS app
Error output from Xcode build:
↳
    ** BUILD FAILED **
Xcode's output:
↳
    === BUILD TARGET map_view OF PROJECT Pods WITH CONFIGURATION Debug ===
    /Users/harshavardhan/Workspace/fleetconnect_flutter/ios/Pods/FMDB/src/fmdb/FMDatabase.m:1486:15: warning: 'sqlite3_wal_checkpoint_v2' is only available on iOS 5.0 or newer [-Wunguarded-availability]
        int err = sqlite3_wal_checkpoint_v2(_db, dbName, checkpointMode, logFrameCount, checkpointCount);
                  ^~~~~~~~~~~~~~~~~~~~~~~~~
    In module 'SQLite3' imported from /Users/harshavardhan/Workspace/fleetconnect_flutter/ios/Pods/FMDB/src/fmdb/FMDatabase.m:8:
    /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator12.1.sdk/usr/include/sqlite3.h:8244:16: note: 'sqlite3_wal_checkpoint_v2' has been explicitly marked partial here
    SQLITE_API int sqlite3_wal_checkpoint_v2(
                   ^
    /Users/harshavardhan/Workspace/fleetconnect_flutter/ios/Pods/FMDB/src/fmdb/FMDatabase.m:1486:15: note: enclose 'sqlite3_wal_checkpoint_v2' in an @available check to silence this warning
        int err = sqlite3_wal_checkpoint_v2(_db, dbName, checkpointMode, logFrameCount, checkpointCount);
                  ^~~~~~~~~~~~~~~~~~~~~~~~~
    1 warning generated.
    === BUILD TARGET map_view OF PROJECT Pods WITH CONFIGURATION Debug ===
    /Users/harshavardhan/Workspace/fleetconnect_flutter/ios/Pods/FMDB/src/fmdb/FMDatabaseQueue.m:101:9: warning: 'dispatch_queue_set_specific' is only available on iOS 5.0 or newer [-Wunguarded-availability]
            dispatch_queue_set_specific(_queue, kDispatchQueueSpecificKey, (__bridge void *)self, NULL);
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~
    In module 'Foundation' imported from /Users/harshavardhan/Workspace/fleetconnect_flutter/ios/Pods/FMDB/src/fmdb/FMDatabaseQueue.h:9:
    In module 'CoreFoundation' imported from /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator12.1.sdk/System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:6:
    In module 'Dispatch' imported from /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator12.1.sdk/System/Library/Frameworks/CoreFoundation.framework/Headers/CFStream.h:20:
    /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator12.1.sdk/usr/include/dispatch/queue.h:1352:1: note: 'dispatch_queue_set_specific' has been explicitly marked partial here
    dispatch_queue_set_specific(dispatch_queue_t queue, const void *key,
    ^
    /Users/harshavardhan/Workspace/fleetconnect_flutter/ios/Pods/FMDB/src/fmdb/FMDatabaseQueue.m:101:9: note: enclose 'dispatch_queue_set_specific' in an @available check to silence this warning
            dispatch_queue_set_specific(_queue, kDispatchQueueSpecificKey, (__bridge void *)self, NULL);
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~
    /Users/harshavardhan/Workspace/fleetconnect_flutter/ios/Pods/FMDB/src/fmdb/FMDatabaseQueue.m:184:54: warning: 'dispatch_get_specific' is only available on iOS 5.0 or newer [-Wunguarded-availability]
        FMDatabaseQueue *currentSyncQueue = (__bridge id)dispatch_get_specific(kDispatchQueueSpecificKey);
                                                         ^~~~~~~~~~~~~~~~~~~~~
    In module 'Foundation' imported from /Users/harshavardhan/Workspace/fleetconnect_flutter/ios/Pods/FMDB/src/fmdb/FMDatabaseQueue.h:9:
    In module 'CoreFoundation' imported from /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator12.1.sdk/System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:6:
    In module 'Dispatch' imported from /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator12.1.sdk/System/Library/Frameworks/CoreFoundation.framework/Headers/CFStream.h:20:
    /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator12.1.sdk/usr/include/dispatch/queue.h:1408:1: note: 'dispatch_get_specific' has been explicitly marked partial here
    dispatch_get_specific(const void *key);
    ^
    /Users/harshavardhan/Workspace/fleetconnect_flutter/ios/Pods/FMDB/src/fmdb/FMDatabaseQueue.m:184:54: note: enclose 'dispatch_get_specific' in an @available check to silence this warning
        FMDatabaseQueue *currentSyncQueue = (__bridge id)dispatch_get_specific(kDispatchQueueSpecificKey);
                                                         ^~~~~~~~~~~~~~~~~~~~~
    2 warnings generated.
    /Users/harshavardhan/development/flutter/.pub-cache/hosted/pub.dartlang.org/fluttertoast-2.2.11/ios/Classes/FluttertoastPlugin.m:19:23: warning: unused variable 'viewController' [-Wunused-variable]
        UIViewController *viewController =
                          ^
    /Users/harshavardhan/development/flutter/.pub-cache/hosted/pub.dartlang.org/fluttertoast-2.2.11/ios/Classes/FluttertoastPlugin.m:48:19: warning: unused variable 'size' [-Wunused-variable]
            NSNumber *size = call.arguments[@"size"];
                      ^
    2 warnings generated.
    === BUILD TARGET Runner OF PROJECT Runner WITH CONFIGURATION Debug ===
    ld: framework not found Flutter
    clang: error: linker command failed with exit code 1 (use -v to see invocation)
Could not build the application for the simulator.
Error launching application on iPhone XR.
Exited (sigterm)

最佳答案

尝试在终端中清理项目(Flutter clean)，从ios 目录运行pod install，然后再次运行应用程序.

如果这似乎不能解决问题，others通过按照您自己的建议重新安装 Flutter，他们很幸运地解决了这个问题。

关于ios - 升级我的 flutter 版本后无法构建 iOS 应用程序，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/55594435/