java - ANDROID 两指滑动即可启动应用程序

Question

我有这个代码，它不会返回任何错误。然而它并没有像预期的那样工作。当我用两根手指向上滑动时，我尝试启动应用程序，但没有任何反应。谁能看到我的代码有什么问题吗？

public class HomeActivity extends Activity {

    ImageButton phoneButton;
    ImageButton contactsButton;
    ImageButton messagesButton;
    ImageButton cameraButton;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_home);

        setTitle("Apps");


        loadApps();
        loadListView();
        addClickListener();
        addphoneButtonListener();
        addmessagesButtonListener();
        addcontactsButtonListener();
        addcameraButtonListener();


//Two-Finger Drag Gesture detection
        RelativeLayout TextLoggerLayout = (RelativeLayout)findViewById(R.id.mainLayout);
        TextLoggerLayout.setOnTouchListener(
                new RelativeLayout.OnTouchListener(){

                    @Override
                    public boolean onTouch(View v, MotionEvent m) {
                        handleTouch(m);

                        return true;
                    }

                });



    }
    void handleTouch(MotionEvent m){
        //Number of touches
        int pointerCount = m.getPointerCount();
        if(pointerCount == 2){
            int action = m.getActionMasked();

            switch (action)
            {
                case MotionEvent.ACTION_DOWN:
                    Intent i;
                    PackageManager manager = getPackageManager();
                    try {
                        i = manager.getLaunchIntentForPackage("com.google.android.googlequicksearchbox");
                        if (i == null)
                            throw new PackageManager.NameNotFoundException();
                        i.addCategory(Intent.CATEGORY_LAUNCHER);
                        startActivity(i);
                    } catch (PackageManager.NameNotFoundException e) {

                    }
                    break;
                case MotionEvent.ACTION_UP:

                    break;
                case MotionEvent.ACTION_MOVE:

                    break;
                case MotionEvent.ACTION_POINTER_DOWN:

                    break;


            }


        }
        else {
           //do something
        }
    }

Answer 1

尝试调试handleTouch()以查看其不触发的确切原因。我的猜测是因为您对 MotionEvent.ACTION_DOWN 进行了检查，这在现实世界中对于两个手指来说很难同时发生。

将检查移至 MotionEvent.ACTION_MOVE(这正是您想要的，因为您想要滑动，而不是点击)，然后重试。