无法在音频播放器包导入后运行颤振

Question

我从颤振包中进口了以下音效包。

音频播放器：^0.12.1

它抛出错误，说我需要安装一些东西。基于错误消息，我运行了以下命令。

酿造装可可 吊舱装置

安装已成功完成。

在此之后，当我试图运行我的应用程序时，它开始抛出错误。这个应用程序只不过是一个无状态小部件，带有一个空的MaterialApp()小部件。在我完成上面的安装之前，这是很好的工作。

我试着删除音频播放器的依赖项，但错误仍然存在。试图重新构建并重新启动我的IDE没有帮助。请告诉我出了什么问题。即使在移除依赖项之后，我也不明白为什么错误仍然存在。如果这有关系的话，我用的是Mac。请指点。谢谢。

错误日志：

Launching lib/main.dart on iPhone X in debug mode...
Running pod install...
Running Xcode build...
Xcode build done.                                            1.9s
Failed to build iOS app
Error output from Xcode build:
↳
    ** BUILD FAILED **


Xcode's output:
↳
    === BUILD TARGET path_provider OF PROJECT Pods WITH CONFIGURATION Debug ===
    /Users/myusername/.pub-cache/hosted/pub.dartlang.org/audioplayers-0.12.1/ios/Classes/AudioplayersPlugin.m:232:5: error: use of undeclared identifier 'AVAudioSessionCategory'; did you mean 'AVAudioSessionCategoryRecord'?
        AVAudioSessionCategory category;
        ^~~~~~~~~~~~~~~~~~~~~~
        AVAudioSessionCategoryRecord
    In module 'AVFoundation' imported from /Users/myusername/.pub-cache/hosted/pub.dartlang.org/audioplayers-0.12.1/ios/Classes/AudioplayersPlugin.m:4:
    /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator11.2.sdk/System/Library/Frameworks/AVFoundation.framework/Frameworks/AVFAudio.framework/Headers/AVAudioSession.h:642:28: note: 'AVAudioSessionCategoryRecord' declared here
    AVF_EXPORT NSString *const AVAudioSessionCategoryRecord;
                               ^
    /Users/myusername/.pub-cache/hosted/pub.dartlang.org/audioplayers-0.12.1/ios/Classes/AudioplayersPlugin.m:232:27: error: expected ';' after expression
        AVAudioSessionCategory category;
                              ^
                              ;
    /Users/myusername/.pub-cache/hosted/pub.dartlang.org/audioplayers-0.12.1/ios/Classes/AudioplayersPlugin.m:232:28: error: use of undeclared identifier 'category'
        AVAudioSessionCategory category;
                               ^
    /Users/myusername/.pub-cache/hosted/pub.dartlang.org/audioplayers-0.12.1/ios/Classes/AudioplayersPlugin.m:234:9: error: use of undeclared identifier 'category'
            category = AVAudioSessionCategoryAmbient;
            ^
    /Users/myusername/.pub-cache/hosted/pub.dartlang.org/audioplayers-0.12.1/ios/Classes/AudioplayersPlugin.m:236:9: error: use of undeclared identifier 'category'
            category = AVAudioSessionCategoryPlayback;
            ^
    /Users/myusername/.pub-cache/hosted/pub.dartlang.org/audioplayers-0.12.1/ios/Classes/AudioplayersPlugin.m:239:34: error: use of undeclared identifier 'category'
                        setCategory: category
                                     ^
    /Users/myusername/.pub-cache/hosted/pub.dartlang.org/audioplayers-0.12.1/ios/Classes/AudioplayersPlugin.m:232:5: warning: expression result unused [-Wunused-value]
        AVAudioSessionCategory category;
        ^~~~~~~~~~~~~~~~~~~~~~
    1 warning and 6 errors generated.

Could not build the application for the simulator.
Error launching application on iPhone X.

Answer 1

我有一个解决办法，尽管我承认这不是最好的解决办法。

我的猜测是，Xcode试图将其构建为通用应用程序而不是iOS应用程序，但我对Xcode的了解还不足以证实这一点(我主要是安卓开发人员在玩颤音)。AVAudioSessionCategory不适用于MacOS...only iOS。

在构建之后，我有与上面相同的错误。在AudioplayersPlugin.m，第232行中，您将看到以下内容：

AVAudioSessionCategory category;
if (respectSilence) {
    category = AVAudioSessionCategoryAmbient;
} else {
    category = AVAudioSessionCategoryPlayback;
}
BOOL success = [[AVAudioSession sharedInstance]
                setCategory: category
                error:&error];

代之以：

BOOL success;
if (respectSilence) {
    success = [[AVAudioSession sharedInstance]
               setCategory: AVAudioSessionCategoryAmbient
               error:&error];
} else {
    success = [[AVAudioSession sharedInstance]
               setCategory: AVAudioSessionCategoryPlayback
               error:&error];
}

您的应用程序现在应该在iOS上运行。