常用 Scrollview嵌套Listview寫法如下：
public class NoScrollListView extends ListView {
public NoScrollListView(Context context) {
super(context);
}
public NoScrollListView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public NoScrollListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, expandSpec);
}
}
現在有一個需求，是要在Scrollview嵌套之下的Listview，可折疊item數目(預設顯示2個item，展開顯示全部)，固不可采用上面的高度寫死方法，采用如下寫法：
public class ScrollDisabledListView extends ListView {
private int mPosition;
public ScrollDisabledListView(Context context) {
super(context);
}
public ScrollDisabledListView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ScrollDisabledListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
final int actionMasked = ev.getActionMasked() & MotionEvent.ACTION_MASK;
if (actionMasked == MotionEvent.ACTION_DOWN) {
// 記錄手指按下時的item
mPosition = pointToPosition((int) ev.getX(), (int) ev.getY());
return super.dispatchTouchEvent(ev);
}
if (actionMasked == MotionEvent.ACTION_MOVE) {
// 最關鍵的地方，忽略MOVE 事件
// ListView onTouch擷取不到MOVE事件是以不會發生滾動處理
return true;
}
// 手指擡起時
if (actionMasked == MotionEvent.ACTION_UP
|| actionMasked == MotionEvent.ACTION_CANCEL) {
// 手指按下與擡起都在同一個視圖内，交給父控件處理，這是一個點選事件
if (pointToPosition((int) ev.getX(), (int) ev.getY()) == mPosition) {
super.dispatchTouchEvent(ev);
} else {
// 如果手指已經移出按下時的Item，說明是滾動行為，清理Item pressed狀态
setPressed(false);
invalidate();
return true;
}
}
return super.dispatchTouchEvent(ev);
}
}
另外，給出折疊listview寫法：
private void changeHisListViewHeight(boolean isExpand) {
int itemNum;
if(isExpand || mCommunityData.size() < 2) {//小于兩個情況下不折疊
itemNum = mAdapter.getCount();
} else {
itemNum = 2;
}
View listItem = mAdapter.getView(0, null, historyList);
listItem.measure(0, 0);
int itemHeight = listItem.getMeasuredHeight();
int totalHeight = itemHeight * (itemNum);
totalHeight += (historyList.getDividerHeight() * (itemNum - 1))
+ historyList.getPaddingTop() + historyList.getPaddingBottom();
ViewGroup.LayoutParams params = historyList.getLayoutParams();
params.height = totalHeight;
historyList.setLayoutParams(params);
mAdapter.notifyDataSetChanged();
}