6月10日学习日志

今天学习了定时换壁纸。

首先我们来写一个定时换壁纸的Service：WallPaperService.java

public class WallPaperService extends Service {

    private int current = 0;  //当前壁纸下标
    private int[] papers = new int[]{R.mipmap.gui_1,R.mipmap.gui_2,R.mipmap.gui_3,R.mipmap.gui_4};
    private WallpaperManager wManager = null;   //定义WallpaperManager服务

    @Override
    public void onCreate() {
        super.onCreate();
        wManager = WallpaperManager.getInstance(this);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        if(current >= 4)current = 0;
        try{
            wManager.setResource(papers[current++]);
        }catch(Exception e){e.printStackTrace();}
        return START_STICKY;
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}

接着撸个简单的布局，三个Button：activity_main.xml：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    
    <Button
        android:id="@+id/btn_on"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="开启自动换壁纸" />

    <Button
        android:id="@+id/btn_off"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="关闭自动换壁纸" />

    <Button
        android:id="@+id/btn_clean"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="清除壁纸" />

</LinearLayout>

接着是我们的Activity，在这里实例化aManager并设置定时事件~：MainActivity.java：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button btn_on;
    private Button btn_off;
    private Button btn_clean;
    private AlarmManager aManager;
    private PendingIntent pi;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //①获得AlarmManager对象:
        aManager = (AlarmManager) getSystemService(ALARM_SERVICE);
        //②指定要启动的Service,并指明动作是Servce:
        Intent intent = new Intent(MainActivity.this, WallPaperService.class);
        pi = PendingIntent.getService(MainActivity.this, 0, intent, 0);
        bindViews();
    }

    private void bindViews() {
        btn_on = (Button) findViewById(R.id.btn_on);
        btn_off = (Button) findViewById(R.id.btn_off);
        btn_clean = (Button) findViewById(R.id.btn_clean);
        btn_on.setOnClickListener(this);
        btn_off.setOnClickListener(this);
        btn_clean.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_on:
                aManager.setRepeating(AlarmManager.RTC_WAKEUP, 0, 3000, pi);
                btn_on.setEnabled(false);
                btn_off.setEnabled(true);
                Toast.makeText(MainActivity.this, "自动更换壁纸设置成功", Toast.LENGTH_SHORT).show();
                break;
            case R.id.btn_off:
                btn_on.setEnabled(true);
                btn_off.setEnabled(false);
                aManager.cancel(pi);
                break;
            case R.id.btn_clean:
                try {
                    WallpaperManager.getInstance(getApplicationContext()).clear();
                    Toast.makeText(MainActivity.this, "清除壁纸成功~", Toast.LENGTH_SHORT).show();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                break;
        }
    }
}