android listview 固定列头

package com.nmbb; import android.content.Context; import android.util.AttributeSet; import android.view.GestureDetector.OnGestureListener; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.widget.LinearLayout; import android.widget.ListView; 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(); } }