我正在使用react-native-sensors来获取加速度计读数。它正确读取传感器值。作为React Native的新手,我无法弄清楚如何添加代码来计算sensor.subscribe方法中的加速度向量。
import {
setUpdateIntervalForType,
SensorTypes,
accelerometer,
gyroscope
} from 'react-native-sensors';
........
export default class Accelerometer extends Component {
constructor(props) {
super(props);
setUpdateIntervalForType(SensorTypes.accelerometer, 200);
this.accelSubscription = accelerometer.subscribe(({ x, y, z, timestamp }) =>
this.setState({
accel_x: x,
accel_y: y,
accel_z: z,
})
);
this.state = {
acceleration: 0,
accel_x: 0,
accel_y: 0,
accel_z: 0,
};
}
这是我想要在每次获得新的加速度计读数时执行的计算代码:
const accelx = this.state.accel_x;
const accely = this.state.accel_y;
const accelz = this.state.accel_z;
const lastAccel = this.state.acceleration;
const currAcceleration = Math.sqrt((accelx * accelx) + (accely * accely) + (accelz * accelz));
//I need to delta value to detect changes
const accelerationDelta = currAcceleration - lastAccel;
this.setState({
acceleration: currAcceleration,
});
如果我将代码直接放在accelerometer.subscribe()中,它将抛出错误。我怎么能做到这一点?
你应该把你的代码放在括号内。
在箭头功能中如果你不使用{}
那么你只能写一行
accelerometer.subscribe(({ x, y, z, timestamp }) =>{
this.setState({ accel_x: x });
alert('Test this');
}