本文实例讲述了Android开发之ListView列表刷新和加载更多实现方法。分享给大家供大家参考。具体如下：
上下拉实现刷新和加载更多的ListView，如下：
package com.sin.android.ui;
import android.content.Context;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;
public class DynamicListView extends ListView implements onScrollListener {
public interface DynamicListViewListener {
public boolean onRefreshOrMore(DynamicListView dynamicListView, boolean isRefresh);
}
enum RefreshStatus {
none, normal, willrefresh, refreshing
}
class StatusView extends LinearLayout {
public int height;
public int width;
private ProgressBar progressBar = null;
private TextView textView = null;
private RefreshStatus refreshStatus = RefreshStatus.none;
private String normalString = "下拉刷新";
private String willrefreshString = "松开刷新";
private String refreshingString = "正在刷新";
public StatusView(Context context, AttributeSet attrs) {
super(context, attrs);
initThis(context);
}
public StatusView(Context context) {
super(context);
initThis(context);
}
private void initThis(Context context) {
this.setOrientation(LinearLayout.HORIZONTAL);
this.setGravity(Gravity.CENTER_HORIZonTAL | Gravity.CENTER_VERTICAL);
progressBar = new ProgressBar(context);
progressBar.setLayoutParams(new LinearLayout.LayoutParams(30, 30));
textView = new TextView(context);
textView.setPadding(5, 0, 0, 0);
this.addView(progressBar);
this.addView(textView);
int w = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
int h = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
this.measure(w, h);
height = this.getMeasuredHeight();
width = this.getMeasuredWidth();
this.setRefreshStatus(RefreshStatus.normal);
}
public RefreshStatus getRefreshStatus() {
return refreshStatus;
}
public void setRefreshStatus(RefreshStatus refreshStatus) {
if (this.refreshStatus != refreshStatus) {
this.refreshStatus = refreshStatus;
if(refreshStatus == RefreshStatus.refreshing){
this.progressBar.setVisibility(View.VISIBLE);
}
else{
this.progressBar.setVisibility(View.GONE);
}
refreshStatusString();
this.invalidate();
}
}
private void refreshStatusString() {
switch (refreshStatus) {
case normal:
textView.setText(normalString);
progressBar.setProgress(0);
break;
case willrefresh:
textView.setText(willrefreshString);
break;
case refreshing:
textView.setText(refreshingString);
break;
default:
break;
}
}
public void setStatusStrings(String normalString, String willrefreshString, String refreshingString){
this.normalString = normalString;
this.willrefreshString = willrefreshString;
this.refreshingString = refreshingString;
this.refreshStatusString();
}
}
private StatusView refreshView;
private StatusView moreView;
private int itemFlag = -1;
private boolean isRecorded = false;
private int downY = -1;
private final float minTimesToRefresh = 1.5f;
private final static int ITEM_FLAG_FIRST = 1;
private final static int ITEM_FLAG_NONE = 0;
private final static int ITEM_FLAG_LAST = -1;
// 两个监听器
private DynamicListViewListener onRefreshListener;
private DynamicListViewListener onMoreListener;
// 滚动到低端的时候是否自动加载更多
private boolean doMoreWhenBottom = false;
public DynamicListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initThis(context);
}
public DynamicListView(Context context, AttributeSet attrs) {
super(context, attrs);
initThis(context);
}
public DynamicListView(Context context) {
super(context);
initThis(context);
}
private void initThis(Context context) {
refreshView = new StatusView(context);
moreView = new StatusView(context);
refreshView.setStatusStrings("继续下拉刷新数据...", "松开之后刷新数据...", "正在刷新数据...");
moreView.setStatusStrings("继续上拉加载数据...", "松开之后加载数据...", "正在加载数据...");
this.addHeaderView(refreshView, null, false);
this.addFooterView(moreView, null, false);
this.setonScrollListener(this);
doneRefresh();
doneMore();
}
// 监听器操作
public DynamicListViewListener getonRefreshListener() {
return onRefreshListener;
}
public void setonRefreshListener(DynamicListViewListener onRefreshListener) {
this.onRefreshListener = onRefreshListener;
}
public DynamicListViewListener getonMoreListener() {
return onMoreListener;
}
public void setonMoreListener(DynamicListViewListener onMoreListener) {
this.onMoreListener = onMoreListener;
}
// 设置
public boolean isDoMoreWhenBottom() {
return doMoreWhenBottom;
}
public void setDoMoreWhenBottom(boolean doMoreWhenBottom) {
this.doMoreWhenBottom = doMoreWhenBottom;
}
@Override
public void onScroll(AbsListView l, int t, int oldl, int count) {
// log("%d %d %d", t, oldl, count);
if (t == 0)
itemFlag = ITEM_FLAG_FIRST;
else if ((t + oldl) == count){
itemFlag = ITEM_FLAG_LAST;
if(doMoreWhenBottom && onMoreListener != null && moreView.getRefreshStatus() != RefreshStatus.refreshing){
doMore();
}
}
else {
itemFlag = ITEM_FLAG_NONE;
// isRecorded = false;
}
}
@Override
public void onScrollStateChanged(AbsListView arg0, int arg1) {
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
if (isRecorded == false && (itemFlag == ITEM_FLAG_FIRST && onRefreshListener != null && refreshView.getRefreshStatus() == RefreshStatus.normal || itemFlag == ITEM_FLAG_LAST && onMoreListener != null && moreView.getRefreshStatus() == RefreshStatus.normal)) {
downY = (int) ev.getY(0);
isRecorded = true;
//log("按下，记录：%d flag:%d", downY, itemFlag);
}
break;
case MotionEvent.ACTION_UP: {
isRecorded = false;
if (onRefreshListener != null && refreshView.getRefreshStatus() == RefreshStatus.willrefresh) {
doRefresh();
} else if (refreshView.getRefreshStatus() == RefreshStatus.normal) {
refreshView.setPadding(0, -1 * refreshView.height, 0, 0);
}
if (onMoreListener != null && moreView.getRefreshStatus() == RefreshStatus.willrefresh) {
doMore();
} else if (moreView.getRefreshStatus() == RefreshStatus.normal) {
moreView.setPadding(0, 0, 0, -1 * moreView.height);
}
break;
}
case MotionEvent.ACTION_MOVE: {
if (isRecorded == false && (itemFlag == ITEM_FLAG_FIRST && onRefreshListener != null && refreshView.getRefreshStatus() == RefreshStatus.normal ||
itemFlag == ITEM_FLAG_LAST && onMoreListener != null && moreView.getRefreshStatus() == RefreshStatus.normal)) {
downY = (int) ev.getY(0);
isRecorded = true;
//log("按下，记录：%d flag:%d", downY, itemFlag);
} else if (isRecorded) {
int nowY = (int) ev.getY(0);
int offset = nowY - downY;
if (offset > 0 && itemFlag == ITEM_FLAG_FIRST) {
// 下拉
setSelection(0);
if (offset >= (minTimesToRefresh * refreshView.height)) {
refreshView.setRefreshStatus(RefreshStatus.willrefresh);
} else {
refreshView.setRefreshStatus(RefreshStatus.normal);
}
refreshView.setPadding(0, -1 * (refreshView.height - offset), 0, 0);
} else if(itemFlag == ITEM_FLAG_LAST){
// 上拉
setSelection(this.getCount());
if (offset <= -1 * (minTimesToRefresh * moreView.height)) {
moreView.setRefreshStatus(RefreshStatus.willrefresh);
} else {
moreView.setRefreshStatus(RefreshStatus.normal);
}
moreView.setPadding(0, 0, 0, -1 * (moreView.height + offset));
}
//log("位移:%d", offset);
}
break;
}
default:
break;
}
return super.onTouchEvent(ev);
}
private void doRefresh(){
// log("开始刷新");
refreshView.setRefreshStatus(RefreshStatus.refreshing);
refreshView.setPadding(0, 0, 0, 0);
if(onRefreshListener.onRefreshOrMore(this, true))
doneRefresh();
}
private void doMore(){
// log("加载更多");
moreView.setRefreshStatus(RefreshStatus.refreshing);
moreView.setPadding(0, 0, 0, 0);
if(onMoreListener.onRefreshOrMore(this, false))
doneMore();
}
public void doneRefresh() {
// log("刷新完成!");
refreshView.setRefreshStatus(RefreshStatus.normal);
refreshView.setPadding(0, -1 * refreshView.height, 0, 0);
}
public void doneMore() {
// log("加载完成!");
moreView.setRefreshStatus(RefreshStatus.normal);
moreView.setPadding(0, 0, 0, -1 * moreView.height);
}
public RefreshStatus getRefreshStatus(){
return refreshView.getRefreshStatus();
}
public RefreshStatus getMoreStatus(){
return moreView.getRefreshStatus();
}
// private void log(Object obj) {
// log("%s", obj.toString());
// }
//
// private void log(String format, Object... args) {
// Log.i("DynamicListView", String.format(format, args));
// }
}
使用例子：
package com.sin.android.ui;
import java.util.ArrayList;
import java.util.Date;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Toast;
import com.sin.android.ui.DynamicListView.DynamicListViewListener;
@SuppressLint("HandlerLeak")
public class MainActivity extends Activity implements DynamicListViewListener {
DynamicListView listView;
ArrayList data;
ArrayAdapter adapter;
// 用于刷新控件状态
Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
if (msg.what == 0) {
adapter.notifyDataSetChanged();
listView.doneRefresh();
Toast.makeText(MainActivity.this, "新加载"+msg.arg1+"条数据!", Toast.LENGTH_LONG).show();
} else if (msg.what == 1) {
adapter.notifyDataSetChanged();
listView.doneMore();
} else {
super.handleMessage(msg);
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
listView = new DynamicListView(this);
setContentView(listView);
data = new ArrayList();
for (int i = 1; i < 10; ++i) {
data.add("原始数据" + i);
}
adapter = new ArrayAdapter(this, android.R.layout.simple_expandable_list_item_1, data);
listView.setAdapter(adapter);
listView.setonItemClickListener(new onItemClickListener() {
@Override
public void onItemClick(AdapterView arg0, View arg1, int arg2, long arg3) {
Log.i("",data.get(arg2-1));
}
});
listView.setDoMoreWhenBottom(false); // 滚动到低端的时候不自己加载更多
listView.setonRefreshListener(this);
listView.setonMoreListener(this);
}
@Override
public boolean onRefreshOrMore(DynamicListView dynamicListView, boolean isRefresh) {
if (isRefresh) {
new Thread(new Runnable() {
@Override
public void run() {
// 刷新
ArrayList temp = new ArrayList();
for (int i = 0; i < 3; ++i) {
temp.add(0, new Date().toLocaleString());
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
synchronized (data) {
data.addAll(0, temp);
}
Message message = new Message();
message.what = 0;
message.arg1 = temp.size();
handler.sendMessage(message);
}
}).start();
} else {
new Thread(new Runnable() {
@Override
public void run() {
// 加载更多
ArrayList temp = new ArrayList();
for (int i = 0; i < 3; ++i) {
temp.add(new Date().toLocaleString());
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
synchronized (data) {
data.addAll(temp);
}
handler.sendEmptyMessage(1);
}
}).start();
}
return false;
}
}
运行截图如下：
希望本文所述对大家的Android程序设计有所帮助。
