在实现锁屏功能的时候首先要获得管理员权限，然后通过用户授权，用户如果同意授权，则就可以修改或设置锁屏密码。

具体方法如下：

1，首先要新建一个DeviceAdminReceiver的子类

import android.app.admin.DeviceAdminReceiver;

public class AdminManageReceiver extends DeviceAdminReceiver {

}

2，在清单文件对接收者进行配置

package="com.njupt.testrotate1"

android:versionCode="1"

android:versionName="1.0" >

android:minSdkVersion="8"

android:targetSdkVersion="8" />

android:allowBackup="true"

android:icon="@drawable/ic_launcher"

android:label="@string/app_name"

android:theme="@style/AppTheme" >

android:name="com.njupt.testrotate1.MainActivity"

android:label="@string/app_name" >

android:resource="@xml/my_admin"/>

3，由于清单文件中用到了my_admin.xml,所以在在res目录下新建xml/my_admin.xml，内容如下：

然后在mainActivity中：

private DevicePolicyManager devicePolicyManager;

private boolean isAdminActive;

devicePolicyManager = (DevicePolicyManager) getSystemService(Context.DEVICE_POLICY_SERVICE);

// 申请权限

ComponentName componentName = new ComponentName(this, MyAdmin.class);

// 判断该组件是否有系统管理员的权限

isAdminActive = devicePolicyManager

.isAdminActive(componentName);

if(!isAdminActive){//这一句一定要有...

Intent intent = new Intent();

//指定动作

intent.setAction(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);

//指定给那个组件授权

intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, componentName);

startActivity(intent);

}

if(isAdminActive){

Toast.makeText(this, "具有权限,将进行锁屏....", 1).show();

devicePolicyManager.lockNow();

devicePolicyManager.resetPassword("123321", 0);

}

MainAcitivity的完整代码如下所示：

import android.os.Bundle;

import android.os.Vibrator;

import android.app.Activity;

import android.app.Service;

import android.app.admin.DevicePolicyManager;

import android.content.ComponentName;

import android.content.Context;

import android.content.Intent;

import android.hardware.Sensor;

import android.hardware.SensorEvent;

import android.hardware.SensorEventListener;

import android.hardware.SensorManager;

import android.view.Menu;

import android.view.View;

import android.widget.Button;

import android.widget.TextView;

import android.widget.Toast;

public class MainActivity extends Activity implements SensorEventListener {

private Button clear;

private TextView tv1;

private SensorManager mSensorManager;

private Vibrator vibrator;

private int counter = 1;

private DevicePolicyManager devicePolicyManager;

private boolean isAdminActive;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);

vibrator = (Vibrator) getSystemService(Service.VIBRATOR_SERVICE);

// clear = (Button) findViewById(R.id.clear);

// clear.setOnClickListener(new Button.OnClickListener() {

//

// @Override

// public void onClick(View v) {

// clear.setText("现在给button赋值喽....");

// }

// });

//

tv1 = (TextView) findViewById(R.id.tv1);

devicePolicyManager = (DevicePolicyManager) getSystemService(Context.DEVICE_POLICY_SERVICE);

// 申请权限

ComponentName componentName = new ComponentName(this, MyAdmin.class);

// 判断该组件是否有系统管理员的权限

isAdminActive = devicePolicyManager

.isAdminActive(componentName);

if(!isAdminActive){

Intent intent = new Intent();

//指定动作

intent.setAction(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);

//指定给那个组件授权

intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, componentName);

startActivity(intent);

}

}

@Override

protected void onResume() {

super.onResume();

mSensorManager.registerListener(this,

mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),

SensorManager.SENSOR_DELAY_GAME);

}

@Override

protected void onStop() {

mSensorManager.unregisterListener(this);

super.onStop();

}

@Override

protected void onPause() {

mSensorManager.unregisterListener(this);

super.onPause();

}

@Override

public void onAccuracyChanged(Sensor sensor, int accuracy) {

}

@Override

public void onSensorChanged(SensorEvent event) {

int sensorType = event.sensor.getType();

float[] values = event.values;

float x = values[0];

float y = values[1];

if (sensorType == Sensor.TYPE_ACCELEROMETER) {

tv1.setText("现在的x轴是: " + x + " y轴是: " + y);

if (Math.abs(x) > 9.0 || Math.abs(y) > 9.0) {

// Toast.makeText(this, "现在的垂直方向已经超过了90度,将进行锁屏", 1).show();

vibrator.vibrate(500);

System.out.println("...............isAdminActive: "

+ isAdminActive);

if(isAdminActive){

Toast.makeText(this, "具有权限,将进行锁屏....", 1).show();

devicePolicyManager.lockNow();

devicePolicyManager.resetPassword("123321", 0);

}

}

}

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

}