自定义控件学习——下拉刷新ListView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"> <FrameLayout
android:layout_margin="5dp"
android:layout_width="50dp"
android:layout_height="50dp" > <ImageView
android:id="@+id/iv_arrow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:src="@drawable/common_listview_headview_red_arrow" /> <ProgressBar
android:id="@+id/pb"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:indeterminateDrawable="@drawable/shape_progress"
android:visibility="invisible" />
</FrameLayout> <LinearLayout
android:layout_margin="5dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:orientation="vertical" > <TextView
android:id="@+id/tv_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:text="下拉刷新"
android:textColor="#F00"
android:textSize="18sp" /> <TextView
android:id="@+id/tv_desc_last_refresh"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:singleLine="true"
android:text="最后刷新时间: 2015-10-11 09:20:35"
android:textColor="#666"
android:textSize="14sp" />
</LinearLayout></LinearLayout>

——<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
android:fromDegrees="0"
android:pivotX="50%"
android:pivotY="50%"
android:toDegrees="-360" > <!-- android:innerRadius="20dp" -->
<!-- android:thickness="5dp" -->
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:innerRadiusRatio="2.5"
android:shape="ring"
android:thicknessRatio="10"
android:useLevel="false" >
<gradient
android:centerColor="#44FF0000"
android:endColor="#00000000"
android:startColor="#FF0000"
android:type="sweep" />
</shape></rotate>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="horizontal" > <ProgressBar
android:layout_margin="5dp"
android:layout_width="50dp"
android:layout_height="50dp"
android:indeterminateDrawable="@drawable/shape_progress" /> <TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="加载更多..."
android:textColor="#F00"
android:layout_marginLeft="15dp"
android:textSize="18sp" /></LinearLayout>

import java.text.SimpleDateFormat;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.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;import com.itheima74.refreshlist.R;/**
* 包含下拉刷新功能的ListView
* @author
*
*/
public class RefreshListView extends ListView implements OnScrollListener{ private View mHeaderView; // 头布局
private float downY; // 按下的y坐标
private float moveY; // 移动后的y坐标
private int mHeaderViewHeight; // 头布局高度
public static final int PULL_TO_REFRESH = 0;// 下拉刷新
public static final int RELEASE_REFRESH = 1;// 释放刷新
public static final int REFRESHING = 2; // 刷新中
private int currentState = PULL_TO_REFRESH; // 当前刷新模式
private RotateAnimation rotateUpAnim; // 箭头向上动画
private RotateAnimation rotateDownAnim; // 箭头向下动画
private View mArrowView; // 箭头布局
private TextView mTitleText; // 头布局标题
private ProgressBar pb; // 进度指示器
private TextView mLastRefreshTime; // 最后刷新时间
private OnRefreshListener mListener; // 刷新监听
private View mFooterView; // 脚布局
private int mFooterViewHeight; // 脚布局高度
private boolean isLoadingMore; // 是否正在加载更多 public RefreshListView(Context context) {
super(context);
init();
} public RefreshListView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
} public RefreshListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
} /**
* 初始化头布局, 脚布局
* 滚动监听
*/
private void init() {
initHeaderView();
initAnimation(); initFooterView(); setOnScrollListener(this);
} /**
* 初始化脚布局
*/
private void initFooterView() {
mFooterView = View.inflate(getContext(), R.layout.layout_footer_list, null); mFooterView.measure(0, 0);
mFooterViewHeight = mFooterView.getMeasuredHeight(); // 隐藏脚布局
mFooterView.setPadding(0, -mFooterViewHeight, 0, 0); addFooterView(mFooterView);
} /**
* 初始化头布局的动画
*/
private void initAnimation() {
// 向上转, 围绕着自己的中心, 逆时针旋转0 -> -180.
rotateUpAnim = new RotateAnimation(0f, -180f,
Animation.RELATIVE_TO_SELF, 0.5f,
Animation.RELATIVE_TO_SELF, 0.5f);
rotateUpAnim.setDuration(300);
rotateUpAnim.setFillAfter(true); // 动画停留在结束位置 // 向下转, 围绕着自己的中心, 逆时针旋转 -180 -> -360
rotateDownAnim = new RotateAnimation(-180f, -360,
Animation.RELATIVE_TO_SELF, 0.5f,
Animation.RELATIVE_TO_SELF, 0.5f);
rotateDownAnim.setDuration(300);
rotateDownAnim.setFillAfter(true); // 动画停留在结束位置 } /**
* 初始化头布局
*/
private void initHeaderView() { mHeaderView = View.inflate(getContext(), R.layout.layout_header_list, null);
mArrowView = mHeaderView.findViewById(R.id.iv_arrow);
pb = (ProgressBar) mHeaderView.findViewById(R.id.pb);
mTitleText = (TextView) mHeaderView.findViewById(R.id.tv_title);
mLastRefreshTime = (TextView) mHeaderView.findViewById(R.id.tv_desc_last_refresh); // 提前手动测量宽高
mHeaderView.measure(0, 0);// 按照设置的规则测量 mHeaderViewHeight = mHeaderView.getMeasuredHeight();
System.out.println(" measuredHeight: " + mHeaderViewHeight); // 设置内边距, 可以隐藏当前控件 , -自身高度
mHeaderView.setPadding(0, -mHeaderViewHeight, 0, 0); // 在设置数据适配器之前执行添加 头布局/脚布局 的方法.
addHeaderView(mHeaderView);
} @Override
public boolean onTouchEvent(MotionEvent ev) { // 判断滑动距离, 给Header设置paddingTop
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
downY = ev.getY();
System.out.println("downY: " + downY); break;
case MotionEvent.ACTION_MOVE:
moveY = ev.getY();
System.out.println("moveY: " + moveY);
// 如果是正在刷新中, 就执行父类的处理
if(currentState == REFRESHING){
return super.onTouchEvent(ev);
} float offset = moveY - downY; // 移动的偏移量
// 只有 偏移量>0, 并且当前第一个可见条目索引是0, 才放大头部
if(offset > 0 && getFirstVisiblePosition() == 0){// int paddingTop = -自身高度 + 偏移量 int paddingTop = (int) (- mHeaderViewHeight + offset);
mHeaderView.setPadding(0, paddingTop, 0, 0); if(paddingTop >= 0 && currentState != RELEASE_REFRESH){// 头布局完全显示
System.out.println("切换成释放刷新模式: " + paddingTop);
// 切换成释放刷新模式
currentState = RELEASE_REFRESH;
updateHeader(); // 根据最新的状态值更新头布局内容
}else if(paddingTop < 0 && currentState != PULL_TO_REFRESH){ // 头布局不完全显示
System.out.println("切换成下拉刷新模式: " + paddingTop);
// 切换成下拉刷新模式
currentState = PULL_TO_REFRESH;
updateHeader(); // 根据最新的状态值更新头布局内容
} return true; // 当前事件被我们处理并消费
} break;
case MotionEvent.ACTION_UP: // 根据刚刚设置状态
if(currentState == PULL_TO_REFRESH){
// - paddingTop < 0 不完全显示, 恢复
mHeaderView.setPadding(0, -mHeaderViewHeight, 0, 0);
}else if(currentState == RELEASE_REFRESH){
// - paddingTop >= 0 完全显示, 执行正在刷新...
mHeaderView.setPadding(0, 0, 0, 0);
currentState = REFRESHING;
updateHeader();
}
break; default:
break;
} return super.onTouchEvent(ev);
} /**
* 根据状态更新头布局内容
*/
private void updateHeader() {
switch (currentState) {
case PULL_TO_REFRESH: // 切换回下拉刷新
// 做动画, 改标题
mArrowView.startAnimation(rotateDownAnim);
mTitleText.setText("下拉刷新"); break;
case RELEASE_REFRESH: // 切换成释放刷新
// 做动画, 改标题
mArrowView.startAnimation(rotateUpAnim);
mTitleText.setText("释放刷新"); break;
case REFRESHING: // 刷新中...
mArrowView.clearAnimation();
mArrowView.setVisibility(View.INVISIBLE);
pb.setVisibility(View.VISIBLE);
mTitleText.setText("正在刷新中..."); if(mListener != null){
mListener.onRefresh(); // 通知调用者, 让其到网络加载更多数据.
} break; default:
break;
}
} /**
* 刷新结束, 恢复界面效果
*/
public void onRefreshComplete() {
if(isLoadingMore){
// 加载更多
mFooterView.setPadding(0, -mFooterViewHeight, 0, 0);
isLoadingMore = false;
}else {
// 下拉刷新
currentState = PULL_TO_REFRESH;
mTitleText.setText("下拉刷新"); // 切换文本
mHeaderView.setPadding(0, -mHeaderViewHeight, 0, 0);// 隐藏头布局
pb.setVisibility(View.INVISIBLE);
mArrowView.setVisibility(View.VISIBLE);
String time = getTime();
mLastRefreshTime.setText("最后刷新时间: " + time);
} } private String getTime() {
long currentTimeMillis = System.currentTimeMillis();
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
return format.format(currentTimeMillis);
} public interface OnRefreshListener{ void onRefresh(); // 下拉刷新 void onLoadMore();// 加载更多
} public void setRefreshListener(OnRefreshListener mListener) {
this.mListener = mListener;
}// public static int SCROLL_STATE_IDLE = 0; // 空闲
// public static int SCROLL_STATE_TOUCH_SCROLL = 1; // 触摸滑动
// public static int SCROLL_STATE_FLING = 2; // 滑翔
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// 状态更新的时候
System.out.println("scrollState: " + scrollState);
if(isLoadingMore){
return; // 已经在加载更多.返回
} // 最新状态是空闲状态, 并且当前界面显示了所有数据的最后一条. 加载更多
if(scrollState == SCROLL_STATE_IDLE && getLastVisiblePosition() >= (getCount() - 1)){
isLoadingMore = true;
System.out.println("scrollState: 开始加载更多");
mFooterView.setPadding(0, 0, 0, 0); setSelection(getCount()); // 跳转到最后一条, 使其显示出加载更多. if(mListener != null){
mListener.onLoadMore();
}
}
} @Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// 滑动过程
}}

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.BaseAdapter;
import android.widget.TextView;import java.util.ArrayList;public class MainActivity extends AppCompatActivity {
private RefreshListView listview;
private ArrayList<String> listDatas;
private MyAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);
listDatas = new ArrayList<String>();
for (int i = 0; i < 30; i++) {
listDatas.add("这是一条ListView数据: " + i);
}
listview = (RefreshListView) findViewById(R.id.listview);
listview.setRefreshListener(new RefreshListView.OnRefreshListener() { @Override
public void onRefresh() {
new Thread(){
public void run() {
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
} listDatas.add(0,"我是下拉刷新出来的数据!"); runOnUiThread(new Runnable() { @Override
public void run() {
adapter.notifyDataSetChanged();
listview.onRefreshComplete();
}
});
}; }.start();
} @Override
public void onLoadMore() {
new Thread(){
public void run() {
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
} listDatas.add("我是加载更多出来的数据!1");
listDatas.add("我是加载更多出来的数据!2");
listDatas.add("我是加载更多出来的数据!3"); runOnUiThread(new Runnable() { @Override
public void run() {
adapter.notifyDataSetChanged();
listview.onRefreshComplete();
}
});
}; }.start();
} }); adapter = new MyAdapter();
listview.setAdapter(adapter); } class MyAdapter extends BaseAdapter { @Override
public int getCount() {
return listDatas.size();
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
TextView textView = new TextView(parent.getContext());
textView.setTextSize(18f);
textView.setText(listDatas.get(position)); return textView;
} @Override
public Object getItem(int position) {
return listDatas.get(position);
} @Override
public long getItemId(int position) {
return position;
} }
}

btn1.setOnClickListener(new OnClickListener() { @Override
public void onClick(View v) {
// TODO Auto-generated method stub
Toast tst = Toast.makeText(TestButtonActivity.this, "111111111", Toast.LENGTH_SHORT);
tst.show(); }
});