<?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"> <ImageView android:id="@+id/imageView_down" android:layout_width="14dp" android:layout_height="24dp" android:padding="2dp" android:src="@drawable/svg_down" /> <ProgressBar android:visibility="gone" android:id="@+id/progressBar" style="?android:attr/progressBarStyle" android:layout_width="20dp" android:layout_height="20dp" android:progressDrawable="@drawable/progressBar" /> <TextView android:padding="15dp" android:id="@+id/textView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/pull_to_refresh" android:textSize="16sp" /></LinearLayout>

package com.pull2refresh;import android.animation.ObjectAnimator;import android.animation.ValueAnimator;import android.annotation.TargetApi;import android.content.Context;import android.os.Build;import android.util.AttributeSet;import android.util.Log;import android.view.LayoutInflater;import android.view.MotionEvent;import android.view.View;import android.view.ViewConfiguration;import android.view.ViewGroup;import android.view.animation.RotateAnimation;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.ProgressBar;import android.widget.TextView;import shike.xianrou.com.pull2refresh.R;/** * Created by cjh on 16-9-6. */public class RefreshableView extends LinearLayout implements View.OnTouchListener { private static final String TAG = "RefreshableView"; private static final int REFRESHING = 0;//正在刷新 private static final int ORIGINAL = REFRESHING + 1;//初始狀態 private static final int RELEASE_TO_REFRESHING = ORIGINAL + 1;//釋放即將刷新的狀態 private int current_status = ORIGINAL;//當前最新狀態 private LinearLayout headView;//刷新layout private TextView textView;//刷新layout中的文字提示 private ImageView imageView;//刷新layout中的箭頭 private ProgressBar progressBar;//刷新layout中的進度條 private View view;//手指控制的下拉的View private int hideHeight;//刷新layout要隱藏的高度 private boolean isablePull;//是否可以下拉，例如當 current_status = REFRESHIING 時是不可以下拉拖拽的 private float yDown;//手指按下的坐標 private int touchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();//界限值，防止手指誤觸，過于靈敏 private boolean firstLayout = true;//第一次調用onLayout的時候置為false private int maxMarginTop;//刷新Layout能拉下的最大距離 private MarginLayoutParams marginLayoutParams;//刷新layout的MarginLayoutParams private String pull_to_refresh = "下拉可以刷新"; private String release_to_refresh = "釋放立即刷新"; private String refreshing = "正在刷新…"; private int original_margin = 0;//針對下拉的View存在MarginTop這中特殊值的處理 public interface PullToRefreshListener { void onRefresh(); } private PullToRefreshListener pullToRefreshListener; public void addPullToRefreshListener(PullToRefreshListener pullToRefreshListener) { this.pullToRefreshListener = pullToRefreshListener; } public RefreshableView(Context context) { super(context); init(); } public RefreshableView(Context context, AttributeSet attrs) { super(context, attrs); init(); } public RefreshableView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } @TargetApi(Build.VERSION_CODES.LOLLIPOP) public RefreshableView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { super(context, attrs, defStyleAttr, defStyleRes); init(); } private void init() { headView = (LinearLayout) LayoutInflater.from(getContext()).inflate(R.layout.refresh_layout, null, true); imageView = (ImageView) headView.findViewById(R.id.imageView_down); progressBar = (ProgressBar) headView.findViewById(R.id.progressBar); textView = (TextView) headView.findViewById(R.id.textView); progressBar.setVisibility(View.GONE); setOrientation(VERTICAL); addView(headView, 0); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { super.onLayout(changed, l, t, r, b); Log.d(TAG, "onlayout"); if (changed && firstLayout) {  //將View的Touch時間的處理交給RefreshableView去處理  view = getChildAt(1);  view.setOnTouchListener(this);  //刷新layout的 marginTop 的最大值設為刷新頭的高度  maxMarginTop = headView.getHeight();  //要將控件完全隱藏起來，那么隱藏的高度就設置為控件的高度  hideHeight = -headView.getHeight();  marginLayoutParams = (MarginLayoutParams) headView.getLayoutParams();  marginLayoutParams.topMargin = hideHeight;  headView.setLayoutParams(marginLayoutParams);  //這里必須將firstLayout設置為false,否則在處理Touch是件的過程中，headView在怎么調用setLayoutParams都會被置為初始的隱藏狀態  firstLayout = false;  //如果子View是一個ViewGroup 那么就需要計算出子View的MarginTop的值，因為如果MarginTop不為0，那么子View的Y軸坐標和父View的坐標是不一樣的  if (view instanceof ViewGroup) {  int[] childLocations = new int[2];  int[] viewLocations = new int[2];  view.getLocationOnScreen(viewLocations);  ((ViewGroup) view).getChildAt(0).getLocationOnScreen(childLocations);  original_margin = childLocations[1] - viewLocations[1];  Log.d(TAG, "onLayout viewLocations[1] " + viewLocations[1]);  Log.d(TAG, "onLayout locations[1] " + childLocations[1]);  Log.d(TAG, "onLayout original_margin " + original_margin);  } } } @Override public boolean onTouch(View view, MotionEvent motionEvent) { if (pullToRefreshListener != null) {  isAblePull();  if (isablePull) {  switch (motionEvent.getAction()) {   case MotionEvent.ACTION_DOWN:   yDown = motionEvent.getRawY();   break;   case MotionEvent.ACTION_MOVE:   float yMove = motionEvent.getRawY();   float distance = yMove - yDown;   //如果手勢是向上的，并且手勢在Y軸的移動距離小于界限值，那么就不處理   if (distance < 0 || Math.abs(distance) < touchSlop)    return false;   //MarginTop的距離是手勢距離的1/2,形成費力延遲的效果   marginLayoutParams.topMargin = (int) (distance / 2 + hideHeight);   Log.d(TAG, "topMargin " + marginLayoutParams.topMargin);   //如果大于最大的MarginTop的值的時候，就將值置為 maxMarginTop   if (marginLayoutParams.topMargin >= maxMarginTop)    marginLayoutParams.topMargin = maxMarginTop;   if (marginLayoutParams.topMargin >= 0) {    //當刷新頭完全顯示的時候，改變狀態，置為 釋放刷新的狀態    if (current_status != RELEASE_TO_REFRESHING) {    rotate(0, 180);    textView.setText(release_to_refresh);    }    current_status = RELEASE_TO_REFRESHING;   } else {    //否則就置為初始狀態    if (current_status != ORIGINAL) {    rotate(180, 360);    textView.setText(pull_to_refresh);    }    current_status = ORIGINAL;   }   headView.setLayoutParams(marginLayoutParams);   break;   case MotionEvent.ACTION_CANCEL:   case MotionEvent.ACTION_UP:   float yUp = motionEvent.getRawY();   float dis = yUp - yDown;   if (dis > 0 && Math.abs(dis) > touchSlop)    switch (current_status) {    //釋放刷新    case RELEASE_TO_REFRESHING:     animateMarginTop(marginLayoutParams.topMargin, 0);     imageView.clearAnimation();     imageView.setVisibility(View.GONE);     progressBar.setVisibility(View.VISIBLE);     textView.setText(refreshing);     pullToRefreshListener.onRefresh();     break;    //初始化    case ORIGINAL:     reset();     //從當前的MarginTop的值，轉變到隱藏所需的 MarginTop     animateMarginTop(marginLayoutParams.topMargin, hideHeight);     break;    }   else    return false;   break;  }  return true;  } } return false; } /** * 判斷是否可以下拉 * * @return */ public boolean isAblePull() { //統一判斷，其實主要是對于view是普通View的判斷 if (current_status != REFRESHING)  isablePull = true; else  isablePull = false; if (view instanceof ViewGroup) {  isablePull = false;  View childView = ((ViewGroup) view).getChildAt(0);  int[] viewLocations = new int[2];  int[] childViewLocations = new int[2];  view.getLocationOnScreen(viewLocations);  childView.getLocationOnScreen(childViewLocations);  //這一步中的 original_margin 至關重要，就是用來兼容 子View 有MarginTop屬性的值，當childView 的Y軸坐標 和 計算出了 Margin 值后的父View坐標相等時，說明此時處于可下拉的狀態  if (viewLocations[1] + original_margin == childViewLocations[1])  isablePull = true;  else  isablePull = false; } return isablePull; } private void rotate(int from, int to) { RotateAnimation rotateAnimation = new RotateAnimation(from, to, imageView.getWidth() / 2, imageView.getHeight() / 2); rotateAnimation.setDuration(100); rotateAnimation.setFillAfter(true); imageView.startAnimation(rotateAnimation); } private void animateMarginTop(int from, int to) { ObjectAnimator objectAnimator = ObjectAnimator.ofInt(headView, "cjh", from, to); objectAnimator.setDuration(300); objectAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {  @Override  public void onAnimationUpdate(ValueAnimator valueAnimator) {  int margin = (int) valueAnimator.getAnimatedValue();  marginLayoutParams.topMargin = margin;  headView.setLayoutParams(marginLayoutParams);  } }); objectAnimator.start(); } public void complete() { animateMarginTop(0, hideHeight); reset(); } private void reset() { rotate(180, 360); textView.setText(pull_to_refresh); imageView.setVisibility(View.VISIBLE); progressBar.setVisibility(View.GONE); }}

 <com.pull2refresh.RefreshableView android:id="@+id/refreshableView" android:layout_width="match_parent" android:layout_height="wrap_content" android:gravity="center"> <com.pull2refresh.MTextView  android:id="@+id/mTextView"  android:layout_width="match_parent"  android:layout_height="100dp"  android:background="@color/colorPrimary"  android:gravity="center"  android:text="Hello World!"  android:textSize="22sp" /> </com.pull2refresh.RefreshableView>

... refreshableView.addPullToRefreshListener(new RefreshableView.PullToRefreshListener() {  @Override  public void onRefresh() {  setData();  } });... private void setData() { ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(textView, "text", 1f, 100f); objectAnimator.setDuration(3000); objectAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {  @Override  public void onAnimationUpdate(ValueAnimator valueAnimator) {  textView.setText((Float) valueAnimator.getAnimatedValue());  } }); objectAnimator.addListener(new Animator.AnimatorListener() {  @Override  public void onAnimationStart(Animator animator) {  }  @Override  public void onAnimationEnd(Animator animator) {  refreshableView.complete();  }  @Override  public void onAnimationCancel(Animator animator) {  }  @Override  public void onAnimationRepeat(Animator animator) {  } }); objectAnimator.start(); }