說起在android上要實現類似Launch的抽屜效果，大家一定首先會想起SlidingDrawer。SlidingDrawer是android官方控件之一，但是本文的主角并不是它，而是民間的控件工具集合：android-misc-widgets。android-misc-widgets里面包含幾個widget：Panel、SmoothButton、Switcher、VirtualKeyboard,還有一些動畫特效，本文主要介紹抽屜容器Panel的用法。android-misc-widgets的google工程地址：-widgets/http://code.google.com/p/android-misc。
工程代碼中Panel的演示效果如下所示：
這個Panel控件可以輕易實現不同方向的抽屜效果，比SlidingDrawer有更強的擴展性！
在多次使用Panel的過程中，發現Panel有個bug，會間斷性出現“閃爍”，也就是在onTouchListener里面的觸發ACTION_DOWN后，抽屜瞬間彈出然后瞬間回收(版本日期為Feb 3, 2009)。把原Panel的OnTouchListener加以替換，即以下代碼：
OnTouchListener touchListener = new OnTouchListener() { int initX; int initY; boolean setInitialPosition; public boolean onTouch(View v, MotionEvent event) { if (mState == State.ANIMATING) { // we are animating return false; }// Log.d(TAG, "state: " + mState + " x: " + event.getX() + " y: " + event.getY()); int action = event.getAction(); if (action == MotionEvent.ACTION_DOWN) { if (mBringToFront) { bringToFront(); } initX = 0; initY = 0; if (mContent.getVisibility() == GONE) { // since we may not know content dimensions we use factors here if (mOrientation == VERTICAL) { initY = mPosition == TOP? -1 : 1; } else { initX = mPosition == LEFT? -1 : 1; } } setInitialPosition = true; } else { if (setInitialPosition) { // now we know content dimensions, so we multiply factors... initX *= mContentWidth; initY *= mContentHeight; // ... and set initial panel's position mGestureListener.setScroll(initX, initY); setInitialPosition = false; // for offsetLocation we have to invert values initX = -initX; initY = -initY; } // offset every ACTION_MOVE & ACTION_UP event event.offsetLocation(initX, initY); } if (!mGestureDetector.onTouchEvent(event)) { if (action == MotionEvent.ACTION_UP) { // tup up after scrolling post(startAnimation); } } return false; }};替換為：
OnTouchListener touchListener = new OnTouchListener() { float touchX, touchY; public boolean onTouch(View v, MotionEvent event) { if (mState == State.ANIMATING) { // we are animating return false; } int action = event.getAction(); if (action == MotionEvent.ACTION_DOWN) { if (mBringToFront) { bringToFront(); } touchX = event.getX(); touchY = event.getY(); } if (!mGestureDetector.onTouchEvent(event)) { if (action == MotionEvent.ACTION_UP) { // tup up after scrolling int size = (int) (Math.abs(touchX - event.getX()) + Math .abs(touchY - event.getY())); if (size == mContentWidth || size == mContentHeight) { mState = State.ABOUT_TO_ANIMATE; //Log.e("size", String.valueOf(size)); //Log.e(String.valueOf(mContentWidth),String.valueOf(mContentHeight)); } post(startAnimation); } } return false; }};即可修復這個bug，并且也同樣實現了OnClickListener的功能，可以把原Panel的OnClickListener給刪掉了！
希望本文所述實例對于大家進行Android項目開發能有所幫助。
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