android - react native android 键盘事件

Question

我一直在尝试创建自定义 react native 自定义键盘事件。 具体来说，我一直在尝试检测退格键。

在我的MainApplication.java

public boolean onKeyUp(int keyCode, KeyEvent event) {

  // Filter for delete key being pressed
  if (event.getAction() == KeyEvent.DEL) {
    getReactNativeHost().getReactInstanceManager().getCurrentRea‌​ctContext()
    .getJSModule(DeviceEventManagerModule.RCTDeviceEventEmitter.class)
    .emit("onKeyPressed", keyCode);
  }
  return true;
}

在我的 react 组件中

componentDidMount() {
  if (Platform.OS === 'android') {
    DeviceEventEmitter.addListener('onKeyPressed', this.handleKeyPress);
  }
}

componentWillUnmount() {
    if (Platform.OS === 'android') {
      DeviceEventEmitter.removeListener('onKeyPressed');
    }
}

有人可以给我一些关于为什么没有触发事件的想法吗？

Answer 1

在对 android 开发进行更多研究之后。

使用 Keyevents 检测按下的键是不可靠的。

https://developer.android.com/reference/android/view/KeyEvent.html

As soft input methods can use multiple and inventive ways of inputting text, there is no guarantee that any key press on a soft keyboard will generate a key event: this is left to the IME's discretion, and in fact sending such events is discouraged.