完美实现音乐播放器锁屏页

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首页我们先看一下效果图


下边来说一下实现逻辑,其主要思路就是新建一个activity使其覆盖在锁屏页上边。

一、我们新建一个LockActivty,既然是四大组件之一,必不可少的在AndroidManifest.xml中注册:

<activity    
 android:name=".LockActivity" 
 android:excludeFromRecents="true"    
 android:exported="false"    
 android:launchMode="singleInstance"    
 android:noHistory="true"    
 android:screenOrientation="portrait"    
 android:taskAffinity="com.ztk.lock"    
 android:theme="@style/LockScreenTheme"/>

这里注意,LockActivty的启动模式,我们使用singleInstance,使其单独存在一个activity task中。

android:exported="false"标签,这个标签是用来表示不能被其他应用程序组件调用或跟它交互。

android:noHistory="true",表示该Activity在statck中不留历史痕迹。

style文件如下:

<style name="LockScreenTheme" parent="AppTheme">   
    <item name="android:windowIsTranslucent">true</item>    
    <item name="android:windowBackground">@android:color/transparent</item>    
    <item name="android:colorBackgroundCacheHint">@null</item>    
    <item name="android:backgroundDimEnabled">false</item>    
    <item name="android:windowAnimationStyle">@null</item>    
    <item name="android:windowContentOverlay">@null</item><
/style>

二、在LockActivty的onCreate方法中添加标志,使其能够在锁屏页上显示:

@Override
protected void onCreate(Bundle savedInstanceState) {   
     super.onCreate(savedInstanceState);    
     getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
     fullScreen(this);    
     setContentView(R.layout.activity_lock);

这里同时也加入全屏的代码 fullScreen(this)

public static void fullScreen(Activity activity) {    
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {        
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {            
            //5.x开始需要把颜色设置透明,否则导航栏会呈现系统默认的浅灰色            
            Window window = activity.getWindow();            
            View decorView = window.getDecorView();            
            //两个 flag 要结合使用,表示让应用的主体内容占用系统状态栏的空间            
            int option = View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN                    
                         | View.SYSTEM_UI_FLAG_LAYOUT_STABLE;            
            decorView.setSystemUiVisibility(option);            
            window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);            
            window.setStatusBarColor(Color.TRANSPARENT);        
    } else {            
        Window window = activity.getWindow();            
        WindowManager.LayoutParams attributes = window.getAttributes();            
        int flagTranslucentStatus = WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;            
        attributes.flags |= flagTranslucentStatus;            
        window.setAttributes(attributes);        
    }    
  }
}

三、重写物理返回键使其不能响应返回键。

@Override
public void onBackPressed() {}

四、向右滑动销毁页面,这里我们要用到触摸反馈的知识,自定义一个SlidingFinishLayout的view 继承RelativeLayout在LockActivity的布局文件中引用,这里重写onTouchEvent方法:

@Override
public boolean onTouchEvent(MotionEvent event) {    
    switch (event.getActionMasked()) {        
        case MotionEvent.ACTION_DOWN:            
           downX = tempX = (int) event.getRawX();            
           downY = (int) event.getRawY();            
           break;        
        case MotionEvent.ACTION_MOVE:            
           int moveX = (int) event.getRawX();            
           int deltaX = tempX - moveX;            
           tempX = moveX;            
           if (Math.abs(moveX - downX) > mTouchSlop 
                && Math.abs((int) event.getRawY() - downY) < mTouchSlop) {
               isSliding = true;            
           }            
           if (moveX - downX >= 0 && isSliding) {                
               mParentView.scrollBy(deltaX, 0);            
            }            
           break;        
        case MotionEvent.ACTION_UP:            i
            sSliding = false;            
            if (mParentView.getScrollX() <= -viewWidth / 4) {                
            isFinish = true;                
            scrollRight();            
            } else {                
                  scrollOrigin();                
                  isFinish = false;            
              }            
           break;        
        default:            
        break;    
    }    
    return true;
}

这里只贴出了主要代码,详细代码请看demo,文章末尾会有demo地址。

五、关于下方滑动解锁text的实现,是利用了颜色渐变器和矩阵平移实现:

public class HintTextView extends AppCompatTextView {    
    private Paint paint;        
    private int mWidth;    
    private LinearGradient gradient;    
    private Matrix matrix;    
    /**     
     * 渐变的速度     
     */    
    private int deltaX;  
  
    public HintTextView(Context context) {        
        super(context, null);    
    } 
   
    public HintTextView(Context context, AttributeSet attrs) {        
        super(context, attrs);    
    }    

    {        
    paint = getPaint();    
    } 
   
    @Override    
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {        
        super.onSizeChanged(w, h, oldw, oldh);        
        if(mWidth == 0 ){            
            mWidth = getMeasuredWidth();            
            //颜色渐变器            
            gradient = new LinearGradient(0, 0, mWidth, 0, new int[]{Color.GRAY, Color.WHITE, Color.GRAY}, 
            new float[]{0.3f,0.5f,1.0f}, 
            Shader.TileMode.CLAMP);            
            paint.setShader(gradient);            
            matrix = new Matrix();        
           }    
    }
    
    @Override    
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);        
        if(matrix !=null){            
            deltaX += mWidth / 8;            
            if(deltaX > 2 * mWidth){                
                deltaX = -mWidth;            
             }        
        }        
        //通过矩阵的平移实现        
        matrix.setTranslate(deltaX, 0);        
        gradient.setLocalMatrix(matrix);        
        postInvalidateDelayed(100);    
   }
}

六、最后我们首先新建一个service做接收锁屏键事件的逻辑,使其启动后在任何页面都可以响应锁屏事件让LockActivity出现在锁屏页面上。

1、在AndroidManifest.xml中注册service:

<service    
    android:name=".service.PlayService"    
    android:process=":main" />

2、在service中注册广播接收锁屏事件,并跳转锁屏页面:

ScreenBroadcastReceiver screenBroadcastReceiver;
@Nullable
@Override
public IBinder onBind(Intent intent) {    
    return null;
}
@Override
public void onCreate() {    
    super.onCreate();    
    screenBroadcastReceiver = new ScreenBroadcastReceiver();    
    final IntentFilter filter = new IntentFilter();    
    filter.addAction(Intent.ACTION_SCREEN_OFF);    
    registerReceiver(screenBroadcastReceiver, filter);
}

public class ScreenBroadcastReceiver extends BroadcastReceiver {    
    @Override    
    public void onReceive(Context context, Intent intent) {        
        handleCommandIntent(intent);    
        }
    }

private void handleCommandIntent(Intent intent) {    
    final String action = intent.getAction();    
    if (Intent.ACTION_SCREEN_OFF.equals(action) ){        
        Intent lockScreen = new Intent(this, LockActivity.class);        
        lockScreen.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);        
        startActivity(lockScreen);    
        }
    }
    @Override
    public void onDestroy() {    
        super.onDestroy();    
        unregisterReceiver(screenBroadcastReceiver);
 }

这样,锁屏页面的实现就大概完成了,有一点要注意的是像小米、vivo、等一些手机会有锁屏显示和后台弹出界面权限,默认是关闭的,需要手动打开。解决这个问题最好的方式大概是加白名单吧,哈哈。

demo地址:github.com/still-soul/…