android微博上拉,Android新浪微博下拉刷新(最新消息显示在最上面)

赵朝
2023-12-01

查看最新消息要用到类似新浪微博下拉刷新 功能!把最新的消息显示在最上面!

代码如下:

PullToRefreshListView类代码

package com.markupartist.android.widget;

import java.util.Date;

import com.markupartist.android.example.pulltorefresh.R;

import android.content.Context;

import android.util.AttributeSet;

import android.util.Log;

import android.view.LayoutInflater;

import android.view.MotionEvent;

import android.view.View;

import android.view.ViewGroup;

import android.view.animation.LinearInterpolator;

import android.view.animation.RotateAnimation;

import android.widget.AbsListView;

import android.widget.AbsListView.OnScrollListener;

import android.widget.BaseAdapter;

import android.widget.ImageView;

import android.widget.LinearLayout;

import android.widget.ListView;

import android.widget.ProgressBar;

import android.widget.TextView;

public class PullToRefreshListView extends ListView implements OnScrollListener {

private static final String TAG = "listview";

private final static int RELEASE_To_REFRESH = 0;

private final static int PULL_To_REFRESH = 1;

private final static int REFRESHING = 2;

private final static int DONE = 3;

private final static int LOADING = 4;

// 实际的padding的距离与界面上偏移距离的比例

private final static int RATIO = 3;

private LayoutInflater inflater;

private LinearLayout headView;

private TextView tipsTextview;

private TextView lastUpdatedTextView;

private ImageView arrowImageView;

private ProgressBar progressBar;

private RotateAnimation animation;

private RotateAnimation reverseAnimation;

// 用于保证startY的值在一个完整的touch事件中只被记录一次

private boolean isRecored;

private int headContentWidth;

private int headContentHeight;

private int startY;

private int firstItemIndex;

private int state;

private boolean isBack;

private OnRefreshListener refreshListener;

private boolean isRefreshable;

public PullToRefreshListView(Context context) {

super(context);

init(context);

}

public PullToRefreshListView(Context context, AttributeSet attrs) {

super(context, attrs);

init(context);

}

private void init(Context context) {

setCacheColorHint(context.getResources().getColor(android.R.color.transparent));

inflater = LayoutInflater.from(context);

headView = (LinearLayout) inflater.inflate(R.layout.pull_to_refresh_header, null);

arrowImageView = (ImageView) headView

.findViewById(R.id.head_arrowImageView);

arrowImageView.setMinimumWidth(70);

arrowImageView.setMinimumHeight(50);

progressBar = (ProgressBar) headView

.findViewById(R.id.head_progressBar);

tipsTextview = (TextView) headView.findViewById(R.id.head_tipsTextView);

lastUpdatedTextView = (TextView) headView

.findViewById(R.id.head_lastUpdatedTextView);

measureView(headView);

headContentHeight = headView.getMeasuredHeight();

headContentWidth = headView.getMeasuredWidth();

headView.setPadding(0, -1 * headContentHeight, 0, 0);

headView.invalidate();

Log.v("size", "width:" + headContentWidth + " height:"

+ headContentHeight);

addHeaderView(headView, null, false);

setOnScrollListener(this);

animation = new RotateAnimation(0, -180,

RotateAnimation.RELATIVE_TO_SELF, 0.5f,

RotateAnimation.RELATIVE_TO_SELF, 0.5f);

animation.setInterpolator(new LinearInterpolator());

animation.setDuration(250);

animation.setFillAfter(true);

reverseAnimation = new RotateAnimation(-180, 0,

RotateAnimation.RELATIVE_TO_SELF, 0.5f,

RotateAnimation.RELATIVE_TO_SELF, 0.5f);

reverseAnimation.setInterpolator(new LinearInterpolator());

reverseAnimation.setDuration(200);

reverseAnimation.setFillAfter(true);

state = DONE;

isRefreshable = false;

}

public void onScroll(AbsListView arg0, int firstVisiableItem, int arg2,

int arg3) {

firstItemIndex = firstVisiableItem;

}

public void onScrollStateChanged(AbsListView arg0, int arg1) {

}

public boolean onTouchEvent(MotionEvent event) {

firstItemIndex=getFirstVisiblePosition();

if (isRefreshable) {

switch (event.getAction()) {

case MotionEvent.ACTION_DOWN:

if (firstItemIndex == 0 && !isRecored) {

isRecored = true;

startY = (int) event.getY();

Log.v(TAG, "在down时候记录当前位置‘");

}

break;

case MotionEvent.ACTION_UP:

if (state != REFRESHING && state != LOADING) {

if (state == DONE) {

// 什么都不做

}

if (state == PULL_To_REFRESH) {

state = DONE;

changeHeaderViewByState();

Log.v(TAG, "由下拉刷新状态,到done状态");

}

if (state == RELEASE_To_REFRESH) {

state = REFRESHING;

changeHeaderViewByState();

onRefresh();

Log.v(TAG, "由松开刷新状态,到done状态");

}

}

isRecored = false;

isBack = false;

break;

case MotionEvent.ACTION_MOVE:

int tempY = (int) event.getY();

if (!isRecored && firstItemIndex == 0) {

Log.v(TAG, "在move时候记录下位置");

isRecored = true;

startY = tempY;

}

if (state != REFRESHING && isRecored && state != LOADING) {

// 保证在设置padding的过程中,当前的位置一直是在head,否则如果当列表超出屏幕的话,当在上推的时候,列表会同时进行滚动

// 可以松手去刷新了

if (state == RELEASE_To_REFRESH) {

setSelection(0);

// 往上推了,推到了屏幕足够掩盖head的程度,但是还没有推到全部掩盖的地步

if (((tempY - startY) / RATIO < headContentHeight)

&& (tempY - startY) > 0) {

state = PULL_To_REFRESH;

changeHeaderViewByState();

Log.v(TAG, "由松开刷新状态转变到下拉刷新状态");

}

// 一下子推到顶了

else if (tempY - startY <= 0) {

state = DONE;

changeHeaderViewByState();

Log.v(TAG, "由松开刷新状态转变到done状态");

}

// 往下拉了,或者还没有上推到屏幕顶部掩盖head的地步

else {

// 不用进行特别的操作,只用更新paddingTop的值就行了

}

}

// 还没有到达显示松开刷新的时候,DONE或者是PULL_To_REFRESH状态

if (state == PULL_To_REFRESH) {

setSelection(0);

// 下拉到可以进入RELEASE_TO_REFRESH的状态

if ((tempY - startY) / RATIO >= headContentHeight) {

state = RELEASE_To_REFRESH;

isBack = true;

changeHeaderViewByState();

Log.v(TAG, "由done或者下拉刷新状态转变到松开刷新");

}

// 上推到顶了

else if (tempY - startY <= 0) {

state = DONE;

changeHeaderViewByState();

Log.v(TAG, "由DOne或者下拉刷新状态转变到done状态");

}

}

// done状态下

if (state == DONE) {

if (tempY - startY > 0) {

state = PULL_To_REFRESH;

changeHeaderViewByState();

}

}

// 更新headView的size

if (state == PULL_To_REFRESH) {

headView.setPadding(0, -1 * headContentHeight

+ (tempY - startY) / RATIO, 0, 0);

}

// 更新headView的paddingTop

if (state == RELEASE_To_REFRESH) {

headView.setPadding(0, (tempY - startY) / RATIO

- headContentHeight, 0, 0);

}

}

break;

}

}

return super.onTouchEvent(event);

}

// 当状态改变时候,调用该方法,以更新界面

private void changeHeaderViewByState() {

switch (state) {

case RELEASE_To_REFRESH:

arrowImageView.setVisibility(View.VISIBLE);

progressBar.setVisibility(View.GONE);

tipsTextview.setVisibility(View.VISIBLE);

lastUpdatedTextView.setVisibility(View.VISIBLE);

arrowImageView.clearAnimation();

arrowImageView.startAnimation(animation);

tipsTextview.setText("松开刷新");

Log.v(TAG, "当前状态,松开刷新");

break;

case PULL_To_REFRESH:

progressBar.setVisibility(View.GONE);

tipsTextview.setVisibility(View.VISIBLE);

lastUpdatedTextView.setVisibility(View.VISIBLE);

arrowImageView.clearAnimation();

arrowImageView.setVisibility(View.VISIBLE);

// 是由RELEASE_To_REFRESH状态转变来的

if (isBack) {

isBack = false;

arrowImageView.clearAnimation();

arrowImageView.startAnimation(reverseAnimation);

tipsTextview.setText("下拉刷新");

} else {

tipsTextview.setText("下拉刷新");

}

Log.v(TAG, "当前状态,下拉刷新");

break;

case REFRESHING:

headView.setPadding(0, 0, 0, 0);

progressBar.setVisibility(View.VISIBLE);

arrowImageView.clearAnimation();

arrowImageView.setVisibility(View.GONE);

tipsTextview.setText("正在刷新...");

lastUpdatedTextView.setVisibility(View.VISIBLE);

Log.v(TAG, "当前状态,正在刷新...");

break;

case DONE:

headView.setPadding(0, -1 * headContentHeight, 0, 0);

progressBar.setVisibility(View.GONE);

arrowImageView.clearAnimation();

arrowImageView.setImageResource(R.drawable.ic_pulltorefresh_arrow);

tipsTextview.setText("下拉刷新");

lastUpdatedTextView.setVisibility(View.VISIBLE);

Log.v(TAG, "当前状态,done");

break;

}

}

public void setOnRefreshListener(OnRefreshListener refreshListener) {

this.refreshListener = refreshListener;

isRefreshable = true;

}

public interface OnRefreshListener {

public void onRefresh();

}

public void onRefreshComplete() {

state = DONE;

lastUpdatedTextView.setText("最近更新:" + new Date().toLocaleString());

changeHeaderViewByState();

}

private void onRefresh() {

if (refreshListener != null) {

refreshListener.onRefresh();

}

}

// 此方法直接照搬自网络上的一个下拉刷新的demo,此处是“估计”headView的width以及height

private void measureView(View child) {

ViewGroup.LayoutParams p = child.getLayoutParams();

if (p == null) {

p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,

ViewGroup.LayoutParams.WRAP_CONTENT);

}

int childWidthSpec = ViewGroup.getChildMeasureSpec(0, 0 + 0, p.width);

int lpHeight = p.height;

int childHeightSpec;

if (lpHeight > 0) {

childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight,

MeasureSpec.EXACTLY);

} else {

childHeightSpec = MeasureSpec.makeMeasureSpec(0,

MeasureSpec.UNSPECIFIED);

}

child.measure(childWidthSpec, childHeightSpec);

}

public void setAdapter(BaseAdapter adapter) {

lastUpdatedTextView.setText("最近更新:" + new Date().toLocaleString());

super.setAdapter(adapter);

}

}

activity调用代码

package com.markupartist.android.example.pulltorefresh;

import java.util.Arrays;

import java.util.LinkedList;

import android.app.ListActivity;

import android.os.AsyncTask;

import android.os.Bundle;

import android.widget.ArrayAdapter;

import com.markupartist.android.widget.PullToRefreshListView;

import com.markupartist.android.widget.PullToRefreshListView.OnRefreshListener;

public class PullToRefreshActivity extends ListActivity {

private LinkedList mListItems;

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.pull_to_refresh);

// Set a listener to be invoked when the list should be refreshed.

((PullToRefreshListView) getListView()).setOnRefreshListener(new OnRefreshListener() {

@Override

public void onRefresh() {

// Do work to refresh the list here.

new GetDataTask().execute();

}

});

mListItems = new LinkedList();

mListItems.addAll(Arrays.asList(mStrings));

ArrayAdapter adapter = new ArrayAdapter(this,

android.R.layout.simple_list_item_1, mListItems);

setListAdapter(adapter);

}

private class GetDataTask extends AsyncTask {

@Override

protected String[] doInBackground(Void... params) {

// Simulates a background job.

try {

Thread.sleep(2000);

} catch (InterruptedException e) {

}

return mStrings;

}

@Override

protected void onPostExecute(String[] result) {

mListItems.addFirst("Added after refresh...");

// Call onRefreshComplete when the list has been refreshed.

((PullToRefreshListView) getListView()).onRefreshComplete();

super.onPostExecute(result);

}

}

private String[] mStrings = {

// "Abbaye de Belloc", "Abbaye du Mont des Cats", "Abertam",

// "Abondance", "Ackawi", "Acorn", "Adelost", "Affidelice au Chablis",

"Afuega'l Pitu", "Airag", "Airedale", "Aisy Cendre",

"Allgauer Emmentaler"};

}

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