android scrollview滾動到底部

一行代碼搞定：

mScrollView.fullScroll(ScrollView.FOCUS_DOWN);

源碼中實現該功能的兩個重要方法：

public boolean fullScroll(int direction) {
      boolean down = direction == View.FOCUS_DOWN;
      int height = getHeight();

      mTempRect.top = 0;
      mTempRect.bottom = height;

      if (down) {
          int count = getChildCount();
          if (count > 0) {
              View view = getChildAt(count - 1);
              mTempRect.bottom = view.getBottom() + mPaddingBottom;
              mTempRect.top = mTempRect.bottom - height;
          }
      }

      return scrollAndFocus(direction, mTempRect.top, mTempRect.bottom);
  }

scrollAndFocus

private boolean scrollAndFocus(int direction, int top, int bottom) {
       boolean handled = true;

       int height = getHeight();
       int containerTop = getScrollY();
       int containerBottom = containerTop + height;
       boolean up = direction == View.FOCUS_UP;

       View newFocused = findFocusableViewInBounds(up, top, bottom);
       if (newFocused == null) {
           newFocused = this;
       }

       if (top >= containerTop && bottom <= containerBottom) {
           handled = false;
       } else {
           int delta = up ? (top - containerTop) : (bottom - containerBottom);
           doScrollY(delta);
       }

       if (newFocused != findFocus()) newFocused.requestFocus(direction);

       return handled;
   }