如何在 Android 中检测震动事件?
Android 设备中的加速度传感器用于检测设备的方向。这有助于应用程序在设置为自动旋转时在倾斜时改变方向。此外,多个应用程序使用来自加速度传感器的数据来执行各种操作。例如,可以使用摇晃来暂停设备上正在播放的视频。因此,在本文中,我们将向您展示如何在 Android 中检测抖动运动。 IDE 准备就绪后,请按照以下步骤操作。
分步实施
第 1 步:在 Android Studio 中创建一个新项目
要在 Android Studio 中创建新项目,请参阅如何在 Android Studio 中创建/启动新项目。我们在Kotlin中演示了该应用程序,因此请确保在创建新项目时选择 Kotlin 作为主要语言。
第 2 步:使用 activity_main.xml 文件
导航到app > res > layout > activity_main.xml并将以下代码添加到该文件。下面是activity_main.xml文件的代码。此文件无需更改,因此请保持原样。
XML
Kotlin
package org.geeksforgeeks.detectphysicalshake
import android.content.Context
import android.hardware.Sensor
import android.hardware.SensorEvent
import android.hardware.SensorEventListener
import android.hardware.SensorManager
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import java.util.*
import kotlin.math.sqrt
class MainActivity : AppCompatActivity() {
// Declaring sensorManager
// and acceleration constants
private var sensorManager: SensorManager? = null
private var acceleration = 0f
private var currentAcceleration = 0f
private var lastAcceleration = 0f
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
// Getting the Sensor Manager instance
sensorManager = getSystemService(Context.SENSOR_SERVICE) as SensorManager
Objects.requireNonNull(sensorManager)!!
.registerListener(sensorListener, sensorManager!!
.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL)
acceleration = 10f
currentAcceleration = SensorManager.GRAVITY_EARTH
lastAcceleration = SensorManager.GRAVITY_EARTH
}
private val sensorListener: SensorEventListener = object : SensorEventListener {
override fun onSensorChanged(event: SensorEvent) {
// Fetching x,y,z values
val x = event.values[0]
val y = event.values[1]
val z = event.values[2]
lastAcceleration = currentAcceleration
// Getting current accelerations
// with the help of fetched x,y,z values
currentAcceleration = sqrt((x * x + y * y + z * z).toDouble()).toFloat()
val delta: Float = currentAcceleration - lastAcceleration
acceleration = acceleration * 0.9f + delta
// Display a Toast message if
// acceleration value is over 12
if (acceleration > 12) {
Toast.makeText(applicationContext, "Shake event detected", Toast.LENGTH_SHORT).show()
}
}
override fun onAccuracyChanged(sensor: Sensor, accuracy: Int) {}
}
override fun onResume() {
sensorManager?.registerListener(sensorListener, sensorManager!!.getDefaultSensor(
Sensor .TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL
)
super.onResume()
}
override fun onPause() {
sensorManager!!.unregisterListener(sensorListener)
super.onPause()
}
}
第 3 步:使用 MainActivity.kt 文件
转到MainActivity.kt文件并参考以下代码。下面是MainActivity.kt文件的代码。代码中添加了注释以更详细地理解代码。
科特林
package org.geeksforgeeks.detectphysicalshake
import android.content.Context
import android.hardware.Sensor
import android.hardware.SensorEvent
import android.hardware.SensorEventListener
import android.hardware.SensorManager
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import java.util.*
import kotlin.math.sqrt
class MainActivity : AppCompatActivity() {
// Declaring sensorManager
// and acceleration constants
private var sensorManager: SensorManager? = null
private var acceleration = 0f
private var currentAcceleration = 0f
private var lastAcceleration = 0f
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
// Getting the Sensor Manager instance
sensorManager = getSystemService(Context.SENSOR_SERVICE) as SensorManager
Objects.requireNonNull(sensorManager)!!
.registerListener(sensorListener, sensorManager!!
.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL)
acceleration = 10f
currentAcceleration = SensorManager.GRAVITY_EARTH
lastAcceleration = SensorManager.GRAVITY_EARTH
}
private val sensorListener: SensorEventListener = object : SensorEventListener {
override fun onSensorChanged(event: SensorEvent) {
// Fetching x,y,z values
val x = event.values[0]
val y = event.values[1]
val z = event.values[2]
lastAcceleration = currentAcceleration
// Getting current accelerations
// with the help of fetched x,y,z values
currentAcceleration = sqrt((x * x + y * y + z * z).toDouble()).toFloat()
val delta: Float = currentAcceleration - lastAcceleration
acceleration = acceleration * 0.9f + delta
// Display a Toast message if
// acceleration value is over 12
if (acceleration > 12) {
Toast.makeText(applicationContext, "Shake event detected", Toast.LENGTH_SHORT).show()
}
}
override fun onAccuracyChanged(sensor: Sensor, accuracy: Int) {}
}
override fun onResume() {
sensorManager?.registerListener(sensorListener, sensorManager!!.getDefaultSensor(
Sensor .TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL
)
super.onResume()
}
override fun onPause() {
sensorManager!!.unregisterListener(sensorListener)
super.onPause()
}
}
输出:
您可以观察到,当您摇动设备时,会显示一个 Toast。