編輯:關於Android編程

MainActivity.java
package com.heima52.pullrefresh;
import java.util.ArrayList;
import com.heima52.pullrefresh.view.RefreshListView;
import com.heima52.pullrefresh.view.RefreshListView.OnRefreshListener;
import android.os.Bundle;
import android.os.Handler;
import android.os.SystemClock;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.view.Window;
import android.widget.BaseAdapter;
import android.widget.TextView;
public class MainActivity extends Activity {
private RefreshListView refreshListView;
private ArrayList list = new ArrayList();
private MyAdapter adapter;
private Handler handler = new Handler(){
public void handleMessage(android.os.Message msg) {
//更新UI
adapter.notifyDataSetChanged();
refreshListView.completeRefresh();
};
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
initView();
initData();
}
private void initView() {
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
refreshListView = (RefreshListView) findViewById(R.id.refreshListView);
}
private void initData() {
for (int i = 0; i < 15; i++) {
list.add("listview原來的數據 - "+i);
}
/**
* 填充對象時候是異步的所以有時候getheight有可能是0
*/
// final View headerView = View.inflate(this, R.layout.layout_header, null);
//第一種方法
// headerView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
// @Override
// public void onGlobalLayout() {
// headerView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
// int headerViewHeight = headerView.getHeight();
//
//
// Log.e("MainActivity", "headerViewHeight: "+headerViewHeight);
// headerView.setPadding(0, -headerViewHeight, 0, 0);
// refreshListView.addHeaderView(headerView);//
// }
// });
//第二種方法
// headerView.measure(0, 0);//主動通知系統去測量
// int headerViewHeight = headerView.getMeasuredHeight();
// Log.e("MainActivity", "headerViewHeight: "+headerViewHeight);
// headerView.setPadding(0, -headerViewHeight, 0, 0);
// refreshListView.addHeaderView(headerView);//
adapter = new MyAdapter();
refreshListView.setAdapter(adapter);
refreshListView.setOnRefreshListener(new OnRefreshListener() {
@Override
public void onPullRefresh() {
//需要聯網請求服務器的數據,然後更新UI
requestDataFromServer(false);
}
@Override
public void onLoadingMore() {
requestDataFromServer(true);
}
});
}
/**
* 模擬向服務器請求數據
*/
private void requestDataFromServer(final boolean isLoadingMore){
new Thread(){
public void run() {
SystemClock.sleep(3000);//模擬請求服務器的一個時間長度
if(isLoadingMore){
list.add("加載更多的數據-1");
list.add("加載更多的數據-2");
list.add("加載更多的數據-3");
}else {
list.add(0, "下拉刷新的數據");
}
//在UI線程更新UI
handler.sendEmptyMessage(0);
};
}.start();
}
class MyAdapter extends BaseAdapter{
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
TextView textView = new TextView(MainActivity.this);
textView.setPadding(20, 20, 20, 20);
textView.setTextSize(18);
textView.setText(list.get(position));
return textView;
}
}
}
RefreshListView.java
package com.heima52.pullrefresh.view;
import java.text.SimpleDateFormat;
import java.util.Date;
import com.heima52.pullrefresh.R;
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.view.animation.RotateAnimation;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;
public class RefreshListView extends ListView implements OnScrollListener{
private View headerView;//headerView
private ImageView iv_arrow;
private ProgressBar pb_rotate;
private TextView tv_state,tv_time;
private View footerView;
private int footerViewHeight;
private int headerViewHeight;//headerView高
private int downY;//按下時y坐標
private final int PULL_REFRESH = 0;//下拉刷新的狀態
private final int RELEASE_REFRESH = 1;//松開刷新的狀態
private final int REFRESHING = 2;//正在刷新的狀態
private int currentState = PULL_REFRESH;
private RotateAnimation upAnimation,downAnimation;
private boolean isLoadingMore = false;//當前是否正在處於加載更多
public RefreshListView(Context context) {
super(context);
init();
}
public RefreshListView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init(){
setOnScrollListener(this);
initHeaderView();
initRotateAnimation();
initFooterView();
}
/**
* 初始化headerView
*/
private void initHeaderView() {
headerView = View.inflate(getContext(), R.layout.layout_header, null);
iv_arrow = (ImageView) headerView.findViewById(R.id.iv_arrow);
pb_rotate = (ProgressBar) headerView.findViewById(R.id.pb_rotate);
tv_state = (TextView) headerView.findViewById(R.id.tv_state);
tv_time = (TextView) headerView.findViewById(R.id.tv_time);
headerView.measure(0, 0);//主動通知系統去測量該view;
headerViewHeight = headerView.getMeasuredHeight();
headerView.setPadding(0, -headerViewHeight, 0, 0);
addHeaderView(headerView);
}
/**
* 初始化旋轉動畫
*/
private void initRotateAnimation() {
upAnimation = new RotateAnimation(0, -180,
RotateAnimation.RELATIVE_TO_SELF, 0.5f,
RotateAnimation.RELATIVE_TO_SELF, 0.5f);
upAnimation.setDuration(300);
upAnimation.setFillAfter(true);
downAnimation = new RotateAnimation(-180, -360,
RotateAnimation.RELATIVE_TO_SELF, 0.5f,
RotateAnimation.RELATIVE_TO_SELF, 0.5f);
downAnimation.setDuration(300);
downAnimation.setFillAfter(true);
}
private void initFooterView() {
footerView = View.inflate(getContext(), R.layout.layout_footer, null);
footerView.measure(0, 0);//主動通知系統去測量該view;
footerViewHeight = footerView.getMeasuredHeight();
footerView.setPadding(0, -footerViewHeight, 0, 0);
addFooterView(footerView);
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
downY = (int) ev.getY();
break;
case MotionEvent.ACTION_MOVE:
if(currentState==REFRESHING){
break;
}
int deltaY = (int) (ev.getY() - downY);
int paddingTop = -headerViewHeight + deltaY;
if(paddingTop>-headerViewHeight && getFirstVisiblePosition()==0){
headerView.setPadding(0, paddingTop, 0, 0);
// Log.e("RefreshListView", "paddingTop: "+paddingTop);
if(paddingTop>=0 && currentState==PULL_REFRESH){
//從下拉刷新進入松開刷新狀態
currentState = RELEASE_REFRESH;
refreshHeaderView();
}else if (paddingTop<0 && currentState==RELEASE_REFRESH) {
//進入下拉刷新狀態
currentState = PULL_REFRESH;
refreshHeaderView();
}
return true;//攔截TouchMove,不讓listview處理該次move事件,會造成listview無法滑動
}
break;
case MotionEvent.ACTION_UP:
if(currentState==PULL_REFRESH){
//隱藏headerView
headerView.setPadding(0, -headerViewHeight, 0, 0);
}else if (currentState==RELEASE_REFRESH) {
headerView.setPadding(0, 0, 0, 0);
currentState = REFRESHING;
refreshHeaderView();
if(listener!=null){
listener.onPullRefresh();
}
}
break;
}
return super.onTouchEvent(ev);
}
/**
* 根據currentState來更新headerView
*/
private void refreshHeaderView(){
switch (currentState) {
case PULL_REFRESH:
tv_state.setText("下拉刷新");
iv_arrow.startAnimation(downAnimation);
break;
case RELEASE_REFRESH:
tv_state.setText("松開刷新");
iv_arrow.startAnimation(upAnimation);
break;
case REFRESHING:
iv_arrow.clearAnimation();//因為向上的旋轉動畫有可能沒有執行完
iv_arrow.setVisibility(View.INVISIBLE);
pb_rotate.setVisibility(View.VISIBLE);
tv_state.setText("正在刷新...");
break;
}
}
/**
* 完成刷新操作,重置狀態,在你獲取完數據並更新完adater之後,去在UI線程中調用該方法
*/
public void completeRefresh(){
if(isLoadingMore){
//重置footerView狀態
footerView.setPadding(0, -footerViewHeight, 0, 0);
isLoadingMore = false;
}else {
//重置headerView狀態
headerView.setPadding(0, -headerViewHeight, 0, 0);
currentState = PULL_REFRESH;
pb_rotate.setVisibility(View.INVISIBLE);
iv_arrow.setVisibility(View.VISIBLE);
tv_state.setText("下拉刷新");
tv_time.setText("最後刷新:"+getCurrentTime());
}
}
/**
* 獲取當前系統時間,並格式化
* @return
*/
private String getCurrentTime(){
SimpleDateFormat format = new SimpleDateFormat("yy-MM-dd HH:mm:ss");
return format.format(new Date());
}
private OnRefreshListener listener;
public void setOnRefreshListener(OnRefreshListener listener){
this.listener = listener;
}
public interface OnRefreshListener{
void onPullRefresh();
void onLoadingMore();
}
/**
* SCROLL_STATE_IDLE:閒置狀態,就是手指松開
* SCROLL_STATE_TOUCH_SCROLL:手指觸摸滑動,就是按著來滑動
* SCROLL_STATE_FLING:快速滑動後松開
*/
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
if(scrollState==OnScrollListener.SCROLL_STATE_IDLE
&& getLastVisiblePosition()==(getCount()-1) &&!isLoadingMore){
isLoadingMore = true;
footerView.setPadding(0, 0, 0, 0);//顯示出footerView
setSelection(getCount());//讓listview最後一條顯示出來
if(listener!=null){
listener.onLoadingMore();
}
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
}
}
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