Решение может быть примерно таким:
state = { keyboardopen: false };
BackHandler.removeEventListener("hardwareBackPress", this.handleBackPress);
Keyboard.addListener(
"keyboardDidShow",
() => this.setState({ keyboardopen: !keyboardopen })
);
handleBackPress = () => {
if (keyboardopen) {
// do some thing
} else {
//do some thing else
}
};