我正在尝试为 ReactNative 实现自定义 native 组件。根据文档，我创建了如下所示的所有组件。但我仍然收到错误 Required Unknown Module "MyCustomToast"。请帮我解决这个问题。

SampleToast.java:-

public class SampleToast extends ReactContextBaseJavaModule {


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

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

@ReactMethod
public void showToast(String message) {
    Toast.makeText(getReactApplicationContext(), message, Toast.LENGTH_LONG).show();
}

MakeReactPackage.java:-

public class MakeReactPackage implements ReactPackage {
@Override
public List<NativeModule> createNativeModules(ReactApplicationContext reactContext) {

    List<NativeModule> modules = new ArrayList<>();
    modules.add(new SampleToast(reactContext));
    return modules;

}

@Override
public List<Class<? extends JavaScriptModule>> createJSModules() {
    return Collections.emptyList();
}

@Override
public List<ViewManager> createViewManagers(ReactApplicationContext reactContext) {
    return Arrays.asList();
}

MainActivity.java:-

public class MainActivity extends Activity implements DefaultHardwareBackBtnHandler {

private ReactInstanceManager mReactInstanceManager;
private ReactRootView mReactRootView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mReactRootView = new ReactRootView(this);

    mReactInstanceManager = ReactInstanceManager.builder()
            .setApplication(getApplication())
            .setBundleAssetName("index.android.bundle")
            .setJSMainModuleName("index.android")
            .addPackage(new MainReactPackage())
            .addPackage(new MakeReactPackage())
            .setUseDeveloperSupport(BuildConfig.DEBUG)
            .setInitialLifecycleState(LifecycleState.RESUMED)
            .build();

    mReactRootView.startReactApplication(mReactInstanceManager, "HelloWorldBha", null);

    setContentView(mReactRootView);
}

@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_MENU && mReactInstanceManager != null) {
        mReactInstanceManager.showDevOptionsDialog();
        return true;
    }
    return super.onKeyUp(keyCode, event);
}

@Override
public void onBackPressed() {
    if (mReactInstanceManager != null) {
        mReactInstanceManager.onBackPressed();
    } else {
        super.onBackPressed();
    }
}

@Override
public void invokeDefaultOnBackPressed() {
    super.onBackPressed();
}

@Override
protected void onPause() {
    super.onPause();

    if (mReactInstanceManager != null) {
        mReactInstanceManager.onPause();
    }
}

@Override
protected void onResume() {
    super.onResume();

    if (mReactInstanceManager != null) {
        mReactInstanceManager.onResume(this);
    }
}}

在 JS 中

react-native.js:-

MyCustomToast:require('MyCustomToast'),

SampleToast.js:-

 'use strict';

/**
 * This exposes the native ToastAndroid module as a JS module. This has a function 'show'
 * which takes the following parameters:
 *
 * 1. String message: A string with the text to toast
 * 2. int duration: The duration of the toast. May be ToastAndroid.SHORT or ToastAndroid.LONG
 */
var { NativeModules } = require('react-native');
module.exports = NativeModules.MyCustomToast;

Index.android.js:-

    /**
 * Sample React Native App
 * https://github.com/facebook/react-native
 */
'use strict';

var React = require('react-native');
var toastMessage = require('SampleToast')
var {
    AppRegistry,
    StyleSheet,
    Text,
    View,
    NativeModules
    } = React;




var HelloWorldBha = React.createClass({
    render: function () {
        return (
            <View style={styles.container}>
                <Text style={styles.welcome}>
                    Welcome to React Native!
                </Text>
                <Text style={styles.instructions}>
                    To get started, edit index.android.js
                </Text>
                <Text style={styles.instructions}>
                    Shake or press menu button for dev menu
                </Text>


                toastMessage.show('Bharath Kumar');

            </View>
        );
    }
});

var styles = StyleSheet.create({
    container: {
        flex: 1,
        justifyContent: 'center',
        alignItems: 'center',
        backgroundColor: '#F5FCFF',
    },
    welcome: {
        fontSize: 20,
        textAlign: 'center',
        margin: 10,
    },
    instructions: {
        textAlign: 'center',
        color: '#333333',
        marginBottom: 5,
    },
});

AppRegistry.registerComponent('HelloWorldBha', () => HelloWorldBha);

最佳答案

在 SampleToast.js 中使用 providesModule 注释。所以 SampleToast.js 变成:

/**
 * @providesModule SampleToast
 */

 'use strict';

 /**
  * This exposes the native ToastAndroid module as a JS module. This has a function 'show'
  * which takes the following parameters:
  *
  * 1. String message: A string with the text to toast
  * 2. int duration: The duration of the toast. May be ToastAndroid.SHORT or ToastAndroid.LONG
  */
 var { NativeModules } = require('react-native');
 module.exports = NativeModules.MyCustomToast;

或者，当您在 Index.android.js 中使用 require('SampleToast') 时，您需要提供相对路径。因此，如果 SampleToast.js 和 Index.android.js 位于同一目录中，您将需要

var toastMessage = require('./SampleToast');

就我个人而言，我更喜欢第一种选择。

关于android - 为自定义 native 组件 react native 所需的未知模块，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/33145554/