package com.charming.sensor;
import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
public class MainActivity extends Activity implements SensorEventListener {
private TextView valueView;
private View top, left, right, bottom;
private SensorManager sensorManager;
private Sensor accelerometer;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
}
private void init() {
valueView = (TextView) findViewById(R.id.values);
top = findViewById(R.id.top);
bottom = findViewById(R.id.bottom);
left = findViewById(R.id.left);
right = findViewById(R.id.right);
sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
accelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
}
@Override
protected void onResume() {
super.onResume();
sensorManager.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_UI);
}
@Override
protected void onPause() {
super.onPause();
sensorManager.unregisterListener(this);
}
@Override
public void onSensorChanged(SensorEvent event) {
float[] values = event.values;
float x = values[0] / 10;
float y = values[1] / 10;
int scaleFactor;
if (x > 0) {
scaleFactor = (int) Math.min(x * 255, 255);
right.setBackgroundColor(Color.argb(scaleFactor, 255, 0, 0));
left.setBackgroundColor(Color.TRANSPARENT);
} else {
scaleFactor = (int) Math.min(x * 255, 255);
left.setBackgroundColor(Color.argb(scaleFactor, 255, 0, 0));
right.setBackgroundColor(Color.TRANSPARENT);
}
if (y > 0) {
scaleFactor = (int) Math.min(x * 255, 255);
top.setBackgroundColor(Color.argb(scaleFactor, 255, 0, 0));
bottom.setBackgroundColor(Color.TRANSPARENT);
} else {
scaleFactor = (int) Math.min(x * 255, 255);
bottom.setBackgroundColor(Color.argb(scaleFactor, 255, 0, 0));
top.setBackgroundColor(Color.TRANSPARENT);
}
valueView.setText("x:" + x + " " + "y:" + y);
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
}
布局文件
<?xml version="1.0" encoding="utf-8"?>
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.charming.sensor.MainActivity">
<TableLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:stretchColumns="0, 1, 2">
<TableRow android:layout_weight="1">
<view
android:id="@+id/top"
android:layout_column="1" />
</TableRow>
<TableRow android:layout_weight="1">
<view
android:id="@+id/left"
android:layout_column="0" />
<view
android:id="@+id/right"
android:layout_column="2" />
</TableRow>
<TableRow android:layout_weight="1">
<view
android:id="@+id/bottom"
android:layout_column="1" />
</TableRow>
</TableLayout>
<TextView
android:id="@+id/values"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true" />
log
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.charming.myapplication, PID: 7837
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.charming.myapplication/com.charming.myapplication.MainActivity}: android.view.InflateException: Binary XML file line #16: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: android.view.InflateException: Binary XML file line #16: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
at android.view.LayoutInflater.inflate(LayoutInflater.java:539)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at com.android.internal.policy.PhoneWindow.setContentView(PhoneWindow.java:393)
at android.app.Activity.setContentView(Activity.java:2166)
at com.charming.myapplication.MainActivity.onCreate(MainActivity.java:24)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:738)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:835)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:838)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:838)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at com.android.internal.policy.PhoneWindow.setContentView(PhoneWindow.java:393)
at android.app.Activity.setContentView(Activity.java:2166)
at com.charming.myapplication.MainActivity.onCreate(MainActivity.java:24)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)