/** * 自定义支持横向滚动的ListView * @author 农民伯伯 * */ public class HVListView
extends ListView {
/** 手势 */ private GestureDetector mGesture;
/** 列头 */ public LinearLayout mListHead;
/** 偏移坐标 */ private int mOffset = 0;
/** 屏幕宽度 */ private int screenWidth;
/** 构造函数 */ public HVListView(Context context, AttributeSet attrs) {
super(context, attrs);
mGesture =
new GestureDetector(context, mOnGesture);
}
/** 分发触摸事件 */ @Override
public boolean dispatchTouchEvent(MotionEvent ev) {
super.dispatchTouchEvent(ev);
return mGesture.onTouchEvent(ev);
}
/** 手势 */ private OnGestureListener mOnGesture =
new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onDown(MotionEvent e) {
return true;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2,
float velocityX,
float velocityY) {
return false;
}
/** 滚动 */ @Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX,
float distanceY) {
synchronized (HVListView.
this) {
int moveX = (
int) distanceX;
int curX = mListHead.getScrollX();
int scrollWidth = getWidth();
int dx = moveX;
// 控制越界问题 if (curX + moveX < 0)
dx = 0;
if (curX + moveX + getScreenWidth() > scrollWidth)
dx = scrollWidth - getScreenWidth() - curX;
mOffset += dx;
// 根据手势滚动Item视图 for (
int i = 0, j = getChildCount(); i < j; i++) {
View child = ((ViewGroup) getChildAt(i)).getChildAt(1);
if (child.getScrollX() != mOffset)
child.scrollTo(mOffset, 0);
}
mListHead.scrollBy(dx, 0);
}
requestLayout();
return true;
}
};
/** * 获取屏幕可见范围内最大屏幕 * @return */ public int getScreenWidth() {
if (screenWidth == 0) {
screenWidth = getContext().getResources().getDisplayMetrics().widthPixels;
if (getChildAt(0) !=
null) {
screenWidth -= ((ViewGroup) getChildAt(0)).getChildAt(0)
.getMeasuredWidth();
}
else if (mListHead !=
null) {
// 减去固定第一列 screenWidth -= mListHead.getChildAt(0).getMeasuredWidth();
}
}
return screenWidth;
}
/** 获取列头偏移量 */ public int getHeadScrollX() {
return mListHead.getScrollX();
}
}