android - 服务中的 SurfaceView

Question

我目前正在使用 Activity 在 ICS 及更高版本中使用相机和手电筒，我使用 SurfaceView，现在我的问题是如何在服务中使用相同的代码，如何创建 SurfaceView 并使用相机？

谢谢 。

Answer 1

您应该使用 aTextureSurface而不是 a SurfaceView（可从 API 11 获得）。看看这个问题。

Answer 2

您想在服务中创建一个表面视图并使用该视图到相机。源代码在这里https://github.com/renhongtao/FloatCameraWindow

1.在服务示例中创建表面视图。此解决方案有助于了解如何在服务中创建视图。

使用名为WindowManager的类和名为LayoutParams的参数对象。注意 params.type，在不同的 SDK 版本中可能会失败。

在 AndroidManifest.xml 中

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
<service android:name=".FloatWindowService" />

创建一个新的服务子类

public class TopWindowService extends Service
{
private static WindowManager wm;
private static WindowManager.LayoutParams params;
private Button btn_floatView;

@Override
public void onCreate()
{
    super.onCreate();          
    createFloatView();
}

 private void createFloatView()
{

    btn_floatView = new Button(getApplicationContext());
    btn_floatView.setText("Hello");
    wm = (WindowManager)getSystemService(Context.WINDOW_SERVICE);
    params = new WindowManager.LayoutParams();      
    params.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;
    //in different sdk this type should change 
    params.format = PixelFormat.RGBA_8888; // 
    params.flags = WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
            | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;

    // set float view size
    params.width = 100;
    params.height = 100;

    // set touch listen action
    btn_floatView.setOnTouchListener(new OnTouchListener()
    {
        int lastX, lastY;
        int paramX, paramY;

        public boolean onTouch(View v, MotionEvent event)
        {
            switch (event.getAction())
            {
                case MotionEvent.ACTION_DOWN:
                    lastX = (int) event.getRawX();
                    lastY = (int) event.getRawY();
                    paramX = params.x;
                    paramY = params.y;
                    break;
                case MotionEvent.ACTION_MOVE:
                    int dx = (int) event.getRawX() - lastX;
                    int dy = (int) event.getRawY() - lastY;
                    params.x = paramX + dx;
                    params.y = paramY + dy;

                    wm.updateViewLayout(btn_floatView, params);
                    break;
            }
            return true;
        }
    });

    wm.addView(btn_floatView, params);
    isAdded = true;
}

2.将服务创建的表面设置为相机示例。这部分源码太多了。主要思想是使用类LayoutInflater加载一个xml文件。然后findViewById得到相机需要的表面。如示例 1 所示。使用 WindowManager 添加视图（在 xml 中）。

2.1 准备一个xml包含一个表面视图，名字是cmera_layout

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/camera_window_layout"
    android:layout_width="100dip"
    android:layout_height="100dip"
    android:background="@drawable/ic_launcher_background"
    >       
<SurfaceView
    android:id="@+id/camera_surface"
    android:layout_width="80dip"
    android:layout_height="80dip"
    android:layout_gravity="center" />
</LinearLayout>

2.2 创建视图类

public class FloatWindowCamera extends LinearLayout {
protected  SurfaceView mCameraView; 
public static int viewWidth;
public static int viewHeight;
 private static int statusBarHeight;
private WindowManager mWindowManager;
private WindowManager.LayoutParams mParams;
private float xInScreen;
private float yInScreen;
private float xDownInScreen;
private float yDownInScreen;    
private float xInView;
private float yInView;

public FloatWindowCamera(Context context) {
    super(context);
/************************Main idea here**************************/
    mWindowManager = context.getSystemService(Context.WINDOW_SERVICE);
    LayoutInflater.from(context).inflate(R.layout.cmera_layout, this);
    View view = findViewById(R.id.camera_surface);
    viewWidth = view.getLayoutParams().width;
    viewHeight = view.getLayoutParams().height;
    mCameraView = (SurfaceView) view;
/****************************************************/

}

public SurfaceView getCameraView(){
    return mCameraView;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
    switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:           
        xInView = event.getX();
        yInView = event.getY();
        xDownInScreen = event.getRawX();
        yDownInScreen = event.getRawY() - getStatusBarHeight();
        xInScreen = event.getRawX();
        yInScreen = event.getRawY() - getStatusBarHeight();
        break;
    case MotionEvent.ACTION_MOVE:
        xInScreen = event.getRawX();
        yInScreen = event.getRawY() - getStatusBarHeight();         
        updateViewPosition();
        break;      
    default:
        break;
    }
    return true;
}   
public void setParams(WindowManager.LayoutParams params) {
    mParams = params;
}


private void updateViewPosition() {
    mParams.x = (int) (xInScreen - xInView);
    mParams.y = (int) (yInScreen - yInView);
    mWindowManager.updateViewLayout(this, mParams);
}

private int getStatusBarHeight() {
    if (statusBarHeight == 0) {
        try {
            Class<?> c = Class.forName("com.android.internal.R$dimen");
            Object o = c.newInstance();
            Field field = c.getField("status_bar_height");
            int x = (Integer) field.get(o);
            statusBarHeight = getResources().getDimensionPixelSize(x);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    return statusBarHeight;


}

}

2.3 创建表面视图然后给出对象。

我们使用 TopFloatWindowService 相同的类名

    public class TopWindowService extends Service
        {
...

    @Override
        public void onCreate()
        {

            super.onCreate();           
/********************add the view in WindowManager**************/

            mView = createCameraWindow(getApplicationContext()).getCameraView();

            //**now you can use this mView to the camera**  then startpreview       


        }

public static FloatWindowCamera createCameraWindow(Context context) {
            WindowManager windowManager = context.getSystemService(Context.WINDOW_SERVICE);
            int screenWidth = windowManager.getDefaultDisplay().getWidth();
            int screenHeight = windowManager.getDefaultDisplay().getHeight();
            if (mCameraWindow == null) {
                mCameraWindow = new FloatWindowCamera(context);
                if (mCameraWindowParams == null) {
                    mCameraWindowParams = new LayoutParams();
                    mCameraWindowParams.type = LayoutParams.TYPE_TOAST ;
                    mCameraWindowParams.format = PixelFormat.RGBA_8888;
                    mCameraWindowParams.flags = LayoutParams.FLAG_NOT_TOUCH_MODAL
                            | LayoutParams.FLAG_NOT_FOCUSABLE;
                    mCameraWindowParams.gravity = Gravity.LEFT | Gravity.TOP;
                    mCameraWindowParams.width = FloatWindowCamera.viewWidth;
                    mCameraWindowParams.height = FloatWindowCamera.viewHeight;
                    mCameraWindowParams.x = screenWidth;
                    mCameraWindowParams.y = screenHeight / 2;
                }
                mCameraWindow.setParams(mCameraWindowParams);
//here add the view to show 
                windowManager.addView(mCameraWindow, mCameraWindowParams);
                Log.e("FLOAT","create small success");
            }
            return mCameraWindow;
        }

代码太多了，希望对大家有所帮助。

Answer 3

服务不是使用这些元素的地方。你将无法做到这一点。