React Native：错误：升级后找不到符号

Question

在导入react原生项目expo并升级react后，我遇到了以下问题。

C:\users\user\gramic\android\app\src\main\java\com\shop\mainapplication.java:5:错误：找不到符号import com.facebook.react.reactapplication；^symbol:class ReactApplication Location：package com.facebook.react C:\users\user\gramic\android\app\src\main\java\com\shop\mainapplication.java:13:错误：找不到symbol import com.facebook.react.reactNativeHost；^symbol:class ReactNativeHost位置：包com.facebook.react C:\user\user\gramic\android\app\src\main\java\com\shop\MainApplication.java:21:错误：找不到符号public类MainApplication扩展应用程序实现ReactApplication{^symbol:class ReactApplication C:\user\user\gramic\android\app\src\main\java\com\shop\MainApplication.java:23:错误：找不到符号private final ReactNativeHost\gramic\android\app\src\main\java\com\shop\MainApplication.java:23:错误：找不到符号private final ReactNativeHost mReactNativeHost=new ReactNativeHost（this）{^symbol:class ReactNativeHost location：class MainApplication c:\users\user\gramic\android\app\src\main\java\com\shop\MainApplication.java:39:错误：方法不重写或实现超级类型@override^

    package com.shop;

import android.app.Application;

import com.facebook.react.ReactApplication;
import com.oblador.vectoricons.VectorIconsPackage;
import com.corbt.keepawake.KCKeepAwakePackage;
import com.oblador.vectoricons.VectorIconsPackage;
import com.github.yamill.orientation.OrientationPackage;
import com.BV.LinearGradient.LinearGradientPackage;
import com.brentvatne.react.ReactVideoPackage;

import com.facebook.react.ReactNativeHost;
import com.facebook.react.ReactPackage;
import com.facebook.react.shell.MainReactPackage;
import com.facebook.soloader.SoLoader;

import java.util.Arrays;
import java.util.List;

public class MainApplication extends Application implements ReactApplication {

  private final ReactNativeHost mReactNativeHost = new ReactNativeHost(this) {
    @Override
    public boolean getUseDeveloperSupport() {
      return BuildConfig.DEBUG;
    }

    @Override
    protected List<ReactPackage> getPackages() {
      return Arrays.<ReactPackage>asList(
          new MainReactPackage(),
            new VectorIconsPackage(),
            new VectorIconsPackage(),
            new KCKeepAwakePackage(),
            new VectorIconsPackage(),
            new OrientationPackage(),
            new LinearGradientPackage(),
            new ReactVideoPackage()

      );
    }
  };

  @Override
  public ReactNativeHost getReactNativeHost() {
    return mReactNativeHost;
  }

  @Override
  public void onCreate() {
    super.onCreate();
    SoLoader.init(this, /* native exopackage */ false);
  }
}

Answer 1

第一：使用yarn或NPM安装所有依赖项；

第二：使用下面的代码链接iOS和Android原生代码上的原生依赖关系；

react-native link

第三：发生此错误可能是因为您的RN版本与Android的build.gradle版本不同。当您创建一个react-native应用程序时，可能会创建android应用程序，比如：

android/app/build.gradle

implementation "com.facebook.react:react-native:+"

implementation "com.facebook.react:react-native:0.58.3"