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Turbo Native Modules：Android

现在是编写一些 Android 平台代码的时候了，以确保应用关闭后 localStorage 仍然存在。

第一步是实现生成的 NativeLocalStorageSpec 接口：

android/app/src/main/java/com/nativelocalstorage/NativeLocalStorageModule.java
package com.nativelocalstorage;

import android.content.Context;
import android.content.SharedPreferences;
import com.nativelocalstorage.NativeLocalStorageSpec;
import com.facebook.react.bridge.ReactApplicationContext;

public class NativeLocalStorageModule extends NativeLocalStorageSpec {

  public static final String NAME = "NativeLocalStorage";

  public NativeLocalStorageModule(ReactApplicationContext reactContext) {
    super(reactContext);
  }

  @Override
  public String getName() {
    return NAME;
  }

  @Override
  public void setItem(String value, String key) {
    SharedPreferences sharedPref = getReactApplicationContext().getSharedPreferences("my_prefs", Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPref.edit();
    editor.putString(key, value);
    editor.apply();
  }

  @Override
  public String getItem(String key) {
    SharedPreferences sharedPref = getReactApplicationContext().getSharedPreferences("my_prefs", Context.MODE_PRIVATE);
    String username = sharedPref.getString(key, null);
    return username;
  }

  @Override
  public void removeItem(String key) {
    SharedPreferences sharedPref = getReactApplicationContext().getSharedPreferences("my_prefs", Context.MODE_PRIVATE);
    sharedPref.edit().remove(key).apply();
  }

  @Override
  public void clear() {
    SharedPreferences sharedPref = getReactApplicationContext().getSharedPreferences("my_prefs", Context.MODE_PRIVATE);
    sharedPref.edit().clear().apply();
  }
}

接下来需要创建 NativeLocalStoragePackage。它通过将我们的 Module 封装为 Base Native Package，提供一个用于在 React Native 运行时注册该 Module 的对象：

android/app/src/main/java/com/nativelocalstorage/NativeLocalStoragePackage.java
package com.nativelocalstorage;

import com.facebook.react.BaseReactPackage;
import com.facebook.react.bridge.NativeModule;
import com.facebook.react.bridge.ReactApplicationContext;
import com.facebook.react.module.model.ReactModuleInfo;
import com.facebook.react.module.model.ReactModuleInfoProvider;

import java.util.HashMap;
import java.util.Map;

public class NativeLocalStoragePackage extends BaseReactPackage {

  @Override
  public NativeModule getModule(String name, ReactApplicationContext reactContext) {
    if (name.equals(NativeLocalStorageModule.NAME)) {
      return new NativeLocalStorageModule(reactContext);
    } else {
      return null;
    }
  }

  @Override
  public ReactModuleInfoProvider getReactModuleInfoProvider() {
    return new ReactModuleInfoProvider() {
      @Override
      public Map<String, ReactModuleInfo> getReactModuleInfos() {
        Map<String, ReactModuleInfo> map = new HashMap<>();
        map.put(NativeLocalStorageModule.NAME, new ReactModuleInfo(
          NativeLocalStorageModule.NAME,       // name
          NativeLocalStorageModule.NAME,       // className
          false, // canOverrideExistingModule
          false, // needsEagerInit
          false, // isCXXModule
          true   // isTurboModule
        ));
        return map;
      }
    };
  }
}

最后，需要告诉主应用中的 React Native 如何找到这个 Package。我们将这个过程称为在 React Native 中“注册”该 Package。

在本例中，将其添加为 getPackages 方法返回的内容。

信息

稍后你将了解如何将 Native Modules 作为 npm packages 分发，构建工具会为你自动链接这些 packages

android/app/src/main/java/com/turobmoduleexample/MainApplication.java
package com.inappmodule;

import android.app.Application;
import com.facebook.react.PackageList;
import com.facebook.react.ReactApplication;
import com.facebook.react.ReactHost;
import com.facebook.react.ReactNativeHost;
import com.facebook.react.ReactPackage;
import com.facebook.react.defaults.DefaultNewArchitectureEntryPoint;
import com.facebook.react.defaults.DefaultReactHost;
import com.facebook.react.defaults.DefaultReactNativeHost;
import com.facebook.soloader.SoLoader;
import com.nativelocalstorage.NativeLocalStoragePackage;

import java.util.ArrayList;
import java.util.List;

public class MainApplication extends Application implements ReactApplication {

  private final ReactNativeHost reactNativeHost = new DefaultReactNativeHost(this) {
    @Override
    public List<ReactPackage> getPackages() {
      List<ReactPackage> packages = new PackageList(this).getPackages();
      // Packages that cannot be autolinked yet can be added manually here, for example:
      // packages.add(new MyReactNativePackage());
      packages.add(new NativeLocalStoragePackage());
      return packages;
    }

    @Override
    public String getJSMainModuleName() {
      return "index";
    }

    @Override
    public boolean getUseDeveloperSupport() {
      return BuildConfig.DEBUG;
    }

    @Override
    public boolean isNewArchEnabled() {
      return BuildConfig.IS_NEW_ARCHITECTURE_ENABLED;
    }

    @Override
    public boolean isHermesEnabled() {
      return BuildConfig.IS_HERMES_ENABLED;
    }
  };

  @Override
  public ReactHost getReactHost() {
    return DefaultReactHost.getDefaultReactHost(getApplicationContext(), reactNativeHost);
  }

  @Override
  public void onCreate() {
    super.onCreate();
    SoLoader.init(this, false);
    if (BuildConfig.IS_NEW_ARCHITECTURE_ENABLED) {
      // If you opted-in for the New Architecture, we load the native entry point for this app.
      DefaultNewArchitectureEntryPoint.load();
    }
  }
}

现在可以在模拟器上构建并运行代码：

npm run android