安卓ListView总结(一)
安卓ListView性能优化(二)
安卓ListView下拉刷新和加载(三)
RefreshListView.java: import java.text.SimpleDateFormat; import java.util.Date; import android.content.Context; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import android.view.animation.Animation; import android.view.animation.RotateAnimation; import android.widget.AbsListView; import android.widget.AbsListView.OnScrollListener; import android.widget.AdapterView; import android.widget.ImageView; import android.widget.ListView; import android.widget.ProgressBar; import android.widget.TextView; import com.itheima.zhbj52.R; /** * 下拉刷新的ListView * * @author Kevin * */ public class RefreshListView extends ListView implements OnScrollListener, android.widget.AdapterView.OnItemClickListener { private static final int STATE_PULL_REFRESH = 0;// 下拉刷新 private static final int STATE_RELEASE_REFRESH = 1;// 松开刷新 private static final int STATE_REFRESHING = 2;// 正在刷新 private View mHeaderView; private int startY = -1;// 滑动起点的y坐标 private int mHeaderViewHeight; private int mCurrrentState = STATE_PULL_REFRESH;// 当前状态 private TextView tvTitle; private TextView tvTime; private ImageView ivArrow; private ProgressBar pbProgress; private RotateAnimation animUp; private RotateAnimation animDown; public RefreshListView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); initHeaderView(); initFooterView(); } public RefreshListView(Context context, AttributeSet attrs) { super(context, attrs); initHeaderView(); initFooterView(); } public RefreshListView(Context context) { super(context); initHeaderView(); initFooterView(); } /** * 初始化头布局 */ private void initHeaderView() { mHeaderView = View.inflate(getContext(), R.layout.refresh_header, null); this.addHeaderView(mHeaderView); tvTitle = (TextView) mHeaderView.findViewById(R.id.tv_title); tvTime = (TextView) mHeaderView.findViewById(R.id.tv_time); ivArrow = (ImageView) mHeaderView.findViewById(R.id.iv_arr); pbProgress = (ProgressBar) mHeaderView.findViewById(R.id.pb_progress); mHeaderView.measure(0, 0); mHeaderViewHeight = mHeaderView.getMeasuredHeight(); mHeaderView.setPadding(0, -mHeaderViewHeight, 0, 0);// 隐藏头布局 initArrowAnim(); tvTime.setText("最后刷新时间:" + getCurrentTime()); } /* * 初始化脚布局 */ private void initFooterView() { mFooterView = View.inflate(getContext(), R.layout.refresh_listview_footer, null); this.addFooterView(mFooterView); mFooterView.measure(0, 0); mFooterViewHeight = mFooterView.getMeasuredHeight(); mFooterView.setPadding(0, -mFooterViewHeight, 0, 0);// 隐藏 this.setOnScrollListener(this); } @Override public boolean onTouchEvent(MotionEvent ev) { switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: startY = (int) ev.getRawY(); break; case MotionEvent.ACTION_MOVE: if (startY == -1) {// 确保startY有效 startY = (int) ev.getRawY(); } if (mCurrrentState == STATE_REFRESHING) {// 正在刷新时不做处理 break; } int endY = (int) ev.getRawY(); int dy = endY - startY;// 移动便宜量 if (dy > 0 && getFirstVisiblePosition() == 0) {// 只有下拉并且当前是第一个item,才允许下拉 int padding = dy - mHeaderViewHeight;// 计算padding mHeaderView.setPadding(0, padding, 0, 0);// 设置当前padding if (padding > 0 && mCurrrentState != STATE_RELEASE_REFRESH) {// 状态改为松开刷新 mCurrrentState = STATE_RELEASE_REFRESH; refreshState(); } else if (padding < 0 && mCurrrentState != STATE_PULL_REFRESH) {// 改为下拉刷新状态 mCurrrentState = STATE_PULL_REFRESH; refreshState(); } return true; } break; case MotionEvent.ACTION_UP: startY = -1;// 重置 if (mCurrrentState == STATE_RELEASE_REFRESH) { mCurrrentState = STATE_REFRESHING;// 正在刷新 mHeaderView.setPadding(0, 0, 0, 0);// 显示 refreshState(); } else if (mCurrrentState == STATE_PULL_REFRESH) { mHeaderView.setPadding(0, -mHeaderViewHeight, 0, 0);// 隐藏 } break; default: break; } return super.onTouchEvent(ev); } /** * 刷新下拉控件的布局 */ private void refreshState() { switch (mCurrrentState) { case STATE_PULL_REFRESH: tvTitle.setText("下拉刷新"); ivArrow.setVisibility(View.VISIBLE); pbProgress.setVisibility(View.INVISIBLE); ivArrow.startAnimation(animDown); break; case STATE_RELEASE_REFRESH: tvTitle.setText("松开刷新"); ivArrow.setVisibility(View.VISIBLE); pbProgress.setVisibility(View.INVISIBLE); ivArrow.startAnimation(animUp); break; case STATE_REFRESHING: tvTitle.setText("正在刷新..."); ivArrow.clearAnimation();// 必须先清除动画,才能隐藏 ivArrow.setVisibility(View.INVISIBLE); pbProgress.setVisibility(View.VISIBLE); if (mListener != null) { mListener.onRefresh(); } break; default: break; } } /** * 初始化箭头动画 */ private void initArrowAnim() { // 箭头向上动画 animUp = new RotateAnimation(0, -180, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f); animUp.setDuration(200); animUp.setFillAfter(true); // 箭头向下动画 animDown = new RotateAnimation(-180, 0, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f); animDown.setDuration(200); animDown.setFillAfter(true); } OnRefreshListener mListener; private View mFooterView; private int mFooterViewHeight; public void setOnRefreshListener(OnRefreshListener listener) { mListener = listener; } public interface OnRefreshListener { public void onRefresh(); public void onLoadMore();// 加载下一页数据 } /* * 收起下拉刷新的控件 */ public void onRefreshComplete(boolean success) { if (isLoadingMore) {// 正在加载更多... mFooterView.setPadding(0, -mFooterViewHeight, 0, 0);// 隐藏脚布局 isLoadingMore = false; } else { mCurrrentState = STATE_PULL_REFRESH; tvTitle.setText("下拉刷新"); ivArrow.setVisibility(View.VISIBLE); pbProgress.setVisibility(View.INVISIBLE); mHeaderView.setPadding(0, -mHeaderViewHeight, 0, 0);// 隐藏 if (success) { tvTime.setText("最后刷新时间:" + getCurrentTime()); } } } /** * 获取当前时间 */ public String getCurrentTime() { SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); return format.format(new Date()); } private boolean isLoadingMore; @Override public void onScrollStateChanged(AbsListView view, int scrollState) { if (scrollState == SCROLL_STATE_IDLE || scrollState == SCROLL_STATE_FLING) { if (getLastVisiblePosition() == getCount() - 1 && !isLoadingMore) {// 滑动到最后 System.out.println("到底了....."); mFooterView.setPadding(0, 0, 0, 0);// 显示 setSelection(getCount() - 1);// 改变listview显示位置 isLoadingMore = true; if (mListener != null) { mListener.onLoadMore(); } } } } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { } OnItemClickListener mItemClickListener; @Override public void setOnItemClickListener( android.widget.AdapterView.OnItemClickListener listener) { super.setOnItemClickListener(this); mItemClickListener = listener; } @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { if (mItemClickListener != null) { mItemClickListener.onItemClick(parent, view, position - getHeaderViewsCount(), id); } } } 常用知识点：- ListView滑动出现黑色背景的问题 //设置改属性,颜色值为白色 android:cacheColorHint="#fff" 点击时item的背景颜色 android:listSelector="@android:color/transparent" 分隔线为透明： android:divider="@android:color/transparent" android:dividerHeight="0dp" - 增加头布局 View headerView = View.inflate(mActivity, R.layout.top_news_header_view, null); lvList.addHeaderView(headerView);// 增加顶部新闻为HeaderView getCount()获取items数目 getLastVisiblePosition()最后一个items显示的position. setSelection(getCount() - 1);改变显示位置 // 查看第一个显示的item属于第几个 int firstVisiblePosition = getFirstVisiblePosition();
