传递自定义对象的数组列表以响应来自 android 的本机端

Question

我有一个自定义对象列表 (List)。我需要将此数据发送到 React Native 端以显示在平面列表中。我该怎么做？此列表位于

class NativeToReact(reactContext: ReactApplicationContext,userManager: IUserManager) : ReactContextBaseJavaModule(reactContext)`

Answer 1

您必须将列表映射到 JSON 对象

Answer 2

因为你想发送一个ArrayList，你必须从本机端发送一个WritableArray到react-native。

public class NativeToReactModule extends ReactContextBaseJavaModule {

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

  @Override
  public String getName() {
    return "NativeToReactModule";
  }

  private static WritableMap convertJsonToMap(JSONObject jsonObject) throws JSONException {
    WritableMap map = new WritableNativeMap();

    Iterator<String> iterator = jsonObject.keys();
    while (iterator.hasNext()) {
      String key = iterator.next();
      Object value = jsonObject.get(key);
      if (value instanceof JSONObject) {
        map.putMap(key, convertJsonToMap((JSONObject) value));
      } else if (value instanceof Boolean) {
        map.putBoolean(key, (Boolean) value);
      } else if (value instanceof Integer) {
        map.putInt(key, (Integer) value);
      } else if (value instanceof Double) {
        map.putDouble(key, (Double) value);
      } else if (value instanceof String) {
        map.putString(key, (String) value);
      } else {
        map.putString(key, value.toString());
      }
    }
    return map;
  }

  @ReactMethod
  public void returnArrayOfObjects(Callback successCallback) throws JSONException {
    List<CustomObject> aList = new ArrayList<CustomObject>();
    Gson g = new Gson();

    aList.add(new CustomObject("Nameone", 1));
    aList.add(new CustomObject("nametwo", 132));

    WritableArray array = new WritableNativeArray();
    for (CustomObject co : aList) {
      JSONObject jo = new JSONObject(g.toJson(co));
      WritableMap wm = convertJsonToMap(jo);
      array.pushMap(wm);
    }

    successCallback.invoke(array);
  }
}

在 react-native 方面，您可以为您的原生模块创建一个 javascript 模块，如下所示：

import { NativeModules } from "react-native";
module.exports = NativeModules.NativeToReactModule;

然后您就可以访问您从本机端发送的ArrayList。

import NativeToReact from "./NativeToReactModule";

...
...
...

NativeToReact.returnArrayOfObjects(array => {
  console.log(array, "The array you sent from the native side");
});

注意：答案没有显示使用本机模块的完整设置。

Answer 3

根据 10101010 的答案扩展（或减少？），您 should/could 使用 FB 的助手类来转换值。

import com.facebook.react.bridge.Arguments;
import com.facebook.react.bridge.ReactContextBaseJavaModule;
import com.facebook.react.bridge.ReactApplicationContext;
import com.facebook.react.bridge.ReactMethod;
import com.facebook.react.bridge.WritableMap;
import com.myapp.SomeClass;

public class NativeToReactModule extends ReactContextBaseJavaModule {

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

  @Override
  public String getName() {
    return "NativeToReactModule";
  }

  @ReactMethod
  public void getArray(Callback successCallback) {
    WritableArray array = Arguments.fromList(SomeClass.SomeStaticListValue);
    successCallback.invoke(array);
  }
}

然后在JS端调用：

import { NativeModules } from "react-native"

NativeModules.NativeToReactModule.getArray(array => console.log(array, "The array you sent from the native side"))

传递自定义对象的数组列表以响应来自 android 的本机端

pass an arraylist of custom objects to react native side from android

android

react-native

react-native-bridge