实现效果:
images/loading.gif' data-original="http://images2015.cnblogs.com/blog/1006172/201610/1006172-20161012100250609-1430607268.png" />
图片素材:
--> 首先, 写先下拉刷新时的刷新布局 pull_to_refresh.
1 <resources> 2 <string name="app_name">PullToRefreshTest</string> 3 <string name="pull_to_refresh">下拉可以刷新</string> 4 <string name="release_to_refresh">释放立即刷新</string> 5 <string name="refreshing">正在刷新...</string> 6 <string name="not_updated_yet">暂未更新过</string> 7 <string name="updated_at">上次更新于%1$s前</string> 8 <string name="updated_just_now">刚刚更新</string> 9 <string name="time_error">时间有问题</string>10 </resources>
strings
1 <??> 2 <RelativeLayout ="http://schemas.android.com/apk/res/android" 3 android:id="@+id/pull_to_refresh_head" 4 android:layout_width="match_parent" 5 android:layout_height="60dp"> 6 7 <LinearLayout 8 android:layout_width="200dp" 9 android:layout_height="60dp"10 android:layout_centerInParent="true"11 android:orientation="horizontal">12 13 <RelativeLayout14 android:layout_width="0dp"15 android:layout_height="60dp"16 android:layout_weight="3">17 18 <ImageView19 android:id="@+id/arrow"20 android:layout_width="wrap_content"21 android:layout_height="wrap_content"22 android:layout_centerInParent="true"23 android:src='/images/loading.gif' data-original="@mipmap/indicator_arrow" />24 25 <ProgressBar26 android:id="@+id/progress_bar"27 android:layout_width="30dp"28 android:layout_height="30dp"29 android:layout_centerInParent="true"30 android:visibility="gone" />31 </RelativeLayout>32 33 <LinearLayout34 android:layout_width="0dp"35 android:layout_height="60dp"36 android:layout_weight="12"37 android:orientation="vertical">38 39 <TextView40 android:id="@+id/description"41 android:layout_width="match_parent"42 android:layout_height="0dp"43 android:layout_weight="1"44 android:gravity="center_horizontal|bottom"45 android:text="@string/pull_to_refresh" />46 47 <TextView48 android:id="@+id/updated_at"49 android:layout_width="match_parent"50 android:layout_height="0dp"51 android:layout_weight="1"52 android:gravity="center_horizontal|top"53 android:text="@string/updated_at" />54 </LinearLayout>55 </LinearLayout>56 57 </RelativeLayout>
pull_to_refresh
--> 然后, 也是主要的, 自定义下拉刷新的 View (包含下拉刷新所有操作) RefreshView.java:
1 package com.dragon.android.tofreshlayout; 2 3 import android.content.Context; 4 import android.content.SharedPreferences; 5 import android.os.AsyncTask; 6 import android.os.SystemClock; 7 import android.preference.PreferenceManager; 8 import android.util.AttributeSet; 9 import android.view.LayoutInflater; 10 import android.view.MotionEvent; 11 import android.view.View; 12 import android.view.ViewConfiguration; 13 import android.view.animation.RotateAnimation; 14 import android.widget.ImageView; 15 import android.widget.LinearLayout; 16 import android.widget.ListView; 17 import android.widget.ProgressBar; 18 import android.widget.TextView; 19 20 public class RefreshView extends LinearLayout implements View.OnTouchListener { 21 22 private static final String TAG = RefreshView.class.getSimpleName(); 23 24 public enum PULL_STATUS { 25 STATUS_PULL_TO_REFRESH(0), // 下拉状态 26 STATUS_RELEASE_TO_REFRESH(1), // 释放立即刷新状态 27 STATUS_REFRESHING(2), // 正在刷新状态 28 STATUS_REFRESH_FINISHED(3); // 刷新完成或未刷新状态 29 30 private int status; // 状态 31 32 PULL_STATUS(int value) { 33 this.status = value; 34 } 35 36 public int getValue() { 37 return this.status; 38 } 39 } 40 41 // 下拉头部回滚的速度 42 public static final int SCROLL_SPEED = -20; 43 // 一分钟的毫秒值,用于判断上次的更新时间 44 public static final long ONE_MINUTE = 60 * 1000; 45 // 一小时的毫秒值,用于判断上次的更新时间 46 public static final long ONE_HOUR = 60 * ONE_MINUTE; 47 // 一天的毫秒值,用于判断上次的更新时间 48 public static final long ONE_DAY = 24 * ONE_HOUR; 49 // 一月的毫秒值,用于判断上次的更新时间 50 public static final long ONE_MONTH = 30 * ONE_DAY; 51 // 一年的毫秒值,用于判断上次的更新时间 52 public static final long ONE_YEAR = 12 * ONE_MONTH; 53 // 上次更新时间的字符串常量,用于作为 SharedPreferences 的键值 54 private static final String UPDATED_AT = "updated_at"; 55 56 // 下拉刷新的回调接口 57 private PullToRefreshListener mListener; 58 59 private SharedPreferences preferences; // 用于存储上次更新时间 60 private View header; // 下拉头的View 61 private ListView listView; // 需要去下拉刷新的ListView 62 63 private ProgressBar progressBar; // 刷新时显示的进度条 64 private ImageView arrow; // 指示下拉和释放的箭头 65 private TextView description; // 指示下拉和释放的文字描述 66 private TextView updateAt; // 上次更新时间的文字描述 67 68 private MarginLayoutParams headerLayoutParams; // 下拉头的布局参数 69 private long lastUpdateTime; // 上次更新时间的毫秒值 70 71 // 为了防止不同界面的下拉刷新在上次更新时间上互相有冲突,使用id来做区分 72 private int mId = -1; 73 74 private int hideHeaderHeight; // 下拉头的高度 75 76 /** 77 * 当前处理什么状态,可选值有 STATUS_PULL_TO_REFRESH, STATUS_RELEASE_TO_REFRESH, STATUS_REFRESHING 和 STATUS_REFRESH_FINISHED 78 */ 79 private PULL_STATUS currentStatus = PULL_STATUS.STATUS_REFRESH_FINISHED; 80 81 // 记录上一次的状态是什么,避免进行重复操作 82 private PULL_STATUS lastStatus = currentStatus; 83 84 private float yDown; // 手指按下时的屏幕纵坐标 85 86 private int touchSlop; // 在被判定为滚动之前用户手指可以移动的最大值。 87 88 private boolean loadOnce; // 是否已加载过一次layout,这里onLayout中的初始化只需加载一次 89 90 private boolean ableToPull; // 当前是否可以下拉,只有ListView滚动到头的时候才允许下拉 91 92 /** 93 * 下拉刷新控件的构造函数,会在运行时动态添加一个下拉头的布局 94 */ 95 public RefreshView(Context context, AttributeSet attrs) { 96 super(context, attrs); 97 98 preferences = PreferenceManager.getDefaultSharedPreferences(context); 99 header = LayoutInflater.from(context).inflate(R.layout.pull_to_refresh, null, true);100 progressBar = (ProgressBar) header.findViewById(R.id.progress_bar);101 arrow = (ImageView) header.findViewById(R.id.arrow);102 description = (TextView) header.findViewById(R.id.description);103 updateAt = (TextView) header.findViewById(R.id.updated_at);104 touchSlop = ViewConfiguration.get(context).getScaledTouchSlop();105 106 refreshUpdatedAtValue();107 setOrientation(VERTICAL);108 addView(header, 0);109 110 //Log.d(TAG, "RefreshView Constructor() getChildAt(0): " + getChildAt(0));111 //Log.d(TAG, "RefreshView Constructor() getChildAt(0): " + getChildAt(1));112 113 // listView = (ListView) getChildAt(1);114 // listView.setOnTouchListener(this);115 }116 117 /**118 * 进行一些关键性的初始化操作,比如:将下拉头向上偏移进行隐藏,给 ListView 注册 touch 事件119 */120 @Override121 protected void onLayout(boolean changed, int l, int t, int r, int b) {122 super.onLayout(changed, l, t, r, b);123 if (changed && !loadOnce) {124 hideHeaderHeight = -header.getHeight();125 126 headerLayoutParams = (MarginLayoutParams) header.getLayoutParams();127 headerLayoutParams.topMargin = hideHeaderHeight;128 listView = (ListView) getChildAt(1);129 //Log.d(TAG, "onLayout() getChildAt(0): " + getChildAt(0));130 //Log.d(TAG, "onLayout() listView: " + listView);131 listView.setOnTouchListener(this);132 loadOnce = true;133 }134 }135 136 /**137 * 当 ListView 被触摸时调用,其中处理了各种下拉刷新的具体逻辑138 */139 @Override140 public boolean onTouch(View v, MotionEvent event) {141 setCanAbleToPull(event); // 判断是否可以下拉142 if (ableToPull) {143 switch (event.getAction()) {144 case MotionEvent.ACTION_DOWN:145 yDown = event.getRawY();146 break;147 case MotionEvent.ACTION_MOVE:148 // 获取移动中的 Y 轴的位置149 float yMove = event.getRawY();150 // 获取从按下到移动过程中移动的距离151 int distance = (int) (yMove - yDown);152 153 // 如果手指是上滑状态,并且下拉头是完全隐藏的,就屏蔽下拉事件154 if (distance <= 0 && headerLayoutParams.topMargin <= hideHeaderHeight) {155 return false;156 }157 if (distance < touchSlop) {158 return false;159 }160 // 判断是否已经在刷新状态161 if (currentStatus != PULL_STATUS.STATUS_REFRESHING) {162 // 判断设置的 topMargin 是否 > 0, 默认初始设置为 -header.getHeight()163 if (headerLayoutParams.topMargin > 0) {164 currentStatus = PULL_STATUS.STATUS_RELEASE_TO_REFRESH;165 } else {166 // 否则状态为下拉中的状态167 currentStatus = PULL_STATUS.STATUS_PULL_TO_REFRESH;168 }169 // 通过偏移下拉头的 topMargin 值,来实现下拉效果170 headerLayoutParams.topMargin = (distance / 2) + hideHeaderHeight;171 header.setLayoutParams(headerLayoutParams);172 }173 break;174 case MotionEvent.ACTION_UP:175 default:176 if (currentStatus == PULL_STATUS.STATUS_RELEASE_TO_REFRESH) {177 // 松手时如果是释放立即刷新状态,就去调用正在刷新的任务178 new RefreshingTask().execute();179 } else if (currentStatus == PULL_STATUS.STATUS_PULL_TO_REFRESH) {180 // 松手时如果是下拉状态,就去调用隐藏下拉头的任务181 new HideHeaderTask().execute();182 }183 break;184 }185 // 时刻记得更新下拉头中的信息186 if (currentStatus == PULL_STATUS.STATUS_PULL_TO_REFRESH187 || currentStatus == PULL_STATUS.STATUS_RELEASE_TO_REFRESH) {188 updateHeaderView();189 // 当前正处于下拉或释放状态,要让 ListView 失去焦点,否则被点击的那一项会一直处于选中状态190 listView.setPressed(false);191 listView.setFocusable(false);192 listView.setFocusableInTouchMode(false);193 lastStatus = currentStatus;194 // 当前正处于下拉或释放状态,通过返回 true 屏蔽掉 ListView 的滚动事件195 return true;196 }197 }198 return false;199 }200 201 /**202 * 给下拉刷新控件注册一个**203 *204 * @param listener **的实现205 * @param id 为了防止不同界面的下拉刷新在上次更新时间上互相有冲突,不同界面在注册下拉刷新**时一定要传入不同的 id206 */207 public void setOnRefreshListener(PullToRefreshListener listener, int id) {208 mListener = listener;209 mId = id;210 }211 212 /**213 * 当所有的刷新逻辑完成后,记录调用一下,否则你的 ListView 将一直处于正在刷新状态214 */215 public void finishRefreshing() {216 currentStatus = PULL_STATUS.STATUS_REFRESH_FINISHED;217 preferences.edit().putLong(UPDATED_AT + mId, System.currentTimeMillis()).commit();218 new HideHeaderTask().execute();219 }220 221 /**222 * 根据当前 ListView 的滚动状态来设定 {@link #ableToPull}223 * 的值,每次都需要在 onTouch 中第一个执行,这样可以判断出当前应该是滚动 ListView,还是应该进行下拉224 */225 private void setCanAbleToPull(MotionEvent event) {226 View firstChild = listView.getChildAt(0);227 if (firstChild != null) {228 // 获取 ListView 中第一个Item的位置229 int firstVisiblePos = listView.getFirstVisiblePosition();230 // 判断第一个子控件的 Top 是否和第一个 Item 位置相等231 if (firstVisiblePos == 0 && firstChild.getTop() == 0) {232 if (!ableToPull) {233 // getRawY() 获得的是相对屏幕 Y 方向的位置234 yDown = event.getRawY();235 }236 // 如果首个元素的上边缘,距离父布局值为 0,就说明 ListView 滚动到了最顶部,此时应该允许下拉刷新237 ableToPull = true;238 } else {239 if (headerLayoutParams.topMargin != hideHeaderHeight) {240 headerLayoutParams.topMargin = hideHeaderHeight;241 header.setLayoutParams(headerLayoutParams);242 }243 ableToPull = false;244 }245 } else {246 // 如果 ListView 中没有元素,也应该允许下拉刷新247 ableToPull = true;248 }249 }250 251 /**252 * 更新下拉头中的信息253 */254 private void updateHeaderView() {255 if (lastStatus != currentStatus) {256 if (currentStatus == PULL_STATUS.STATUS_PULL_TO_REFRESH) {257 description.setText(getResources().getString(R.string.pull_to_refresh));258 arrow.setVisibility(View.VISIBLE);259 progressBar.setVisibility(View.GONE);260 rotateArrow();261 } else if (currentStatus == PULL_STATUS.STATUS_RELEASE_TO_REFRESH) {262 description.setText(getResources().getString(R.string.release_to_refresh));263 arrow.setVisibility(View.VISIBLE);264 progressBar.setVisibility(View.GONE);265 rotateArrow();266 } else if (currentStatus == PULL_STATUS.STATUS_REFRESHING) {267 description.setText(getResources().getString(R.string.refreshing));268 progressBar.setVisibility(View.VISIBLE);269 arrow.clearAnimation();270 arrow.setVisibility(View.GONE);271 }272 refreshUpdatedAtValue();273 }274 }275 276 /**277 * 根据当前的状态来旋转箭头278 */279 private void rotateArrow() {280 float pivotX = arrow.getWidth() / 2f;281 float pivotY = arrow.getHeight() / 2f;282 float fromDegrees = 0f;283 float toDegrees = 0f;284 if (currentStatus == PULL_STATUS.STATUS_PULL_TO_REFRESH) {285 fromDegrees = 180f;286 toDegrees = 360f;287 } else if (currentStatus == PULL_STATUS.STATUS_RELEASE_TO_REFRESH) {288 fromDegrees = 0f;289 toDegrees = 180f;290 }291 RotateAnimation animation = new RotateAnimation(fromDegrees, toDegrees, pivotX, pivotY);292 animation.setDuration(100);293 animation.setFillAfter(true);294 arrow.startAnimation(animation);295 }296 297 /**298 * 刷新下拉头中上次更新时间的文字描述299 */300 private void refreshUpdatedAtValue() {301 lastUpdateTime = preferences.getLong(UPDATED_AT + mId, -1);302 long currentTime = System.currentTimeMillis();303 long timePassed = currentTime - lastUpdateTime;304 long timeIntoFormat;305 String updateAtValue;306 if (lastUpdateTime == -1) {307 updateAtValue = getResources().getString(R.string.not_updated_yet);308 } else if (timePassed < 0) {309 updateAtValue = getResources().getString(R.string.time_error);310 } else if (timePassed < ONE_MINUTE) {311 updateAtValue = getResources().getString(R.string.updated_just_now);312 } else if (timePassed < ONE_HOUR) {313 timeIntoFormat = timePassed / ONE_MINUTE;314 String value = timeIntoFormat + "分钟";315 updateAtValue = String.format(getResources().getString(R.string.updated_at), value);316 } else if (timePassed < ONE_DAY) {317 timeIntoFormat = timePassed / ONE_HOUR;318 String value = timeIntoFormat + "小时";319 updateAtValue = String.format(getResources().getString(R.string.updated_at), value);320 } else if (timePassed < ONE_MONTH) {321 timeIntoFormat = timePassed / ONE_DAY;322 String value = timeIntoFormat + "天";323 updateAtValue = String.format(getResources().getString(R.string.updated_at), value);324 } else if (timePassed < ONE_YEAR) {325 timeIntoFormat = timePassed / ONE_MONTH;326 String value = timeIntoFormat + "个月";327 updateAtValue = String.format(getResources().getString(R.string.updated_at), value);328 } else {329 timeIntoFormat = timePassed / ONE_YEAR;330 String value = timeIntoFormat + "年";331 updateAtValue = String.format(getResources().getString(R.string.updated_at), value);332 }333 updateAt.setText(updateAtValue);334 }335 336 /**337 * 正在刷新的任务,在此任务中会去回调注册进来的下拉刷新**338 */339 class RefreshingTask extends AsyncTask<Void, Integer, Void> {340 341 @Override342 protected Void doInBackground(Void... params) {343 int topMargin = headerLayoutParams.topMargin;344 while (true) {345 topMargin = topMargin + SCROLL_SPEED;346 if (topMargin <= 0) {347 topMargin = 0;348 break;349 }350 publishProgress(topMargin);351 SystemClock.sleep(10);352 }353 currentStatus = PULL_STATUS.STATUS_REFRESHING;354 publishProgress(0);355 if (mListener != null) {356 mListener.onRefresh();357 }358 return null;359 }360 361 @Override362 protected void onProgressUpdate(Integer... topMargin) {363 updateHeaderView();364 headerLayoutParams.topMargin = topMargin[0];365 header.setLayoutParams(headerLayoutParams);366 }367 368 }369 370 /**371 * 隐藏下拉头的任务,当未进行下拉刷新或下拉刷新完成后,此任务将会使下拉头重新隐藏372 */373 class HideHeaderTask extends AsyncTask<Void, Integer, Integer> {374 375 @Override376 protected Integer doInBackground(Void... params) {377 int topMargin = headerLayoutParams.topMargin;378 while (true) {379 topMargin = topMargin + SCROLL_SPEED;380 if (topMargin <= hideHeaderHeight) {381 topMargin = hideHeaderHeight;382 break;383 }384 publishProgress(topMargin);385 SystemClock.sleep(10);386 }387 return topMargin;388 }389 390 @Override391 protected void onProgressUpdate(Integer ... topMargin) {392 headerLayoutParams.topMargin = topMargin[0];393 header.setLayoutParams(headerLayoutParams);394 }395 396 @Override397 protected void onPostExecute(Integer topMargin) {398 headerLayoutParams.topMargin = topMargin;399 header.setLayoutParams(headerLayoutParams);400 currentStatus = PULL_STATUS.STATUS_REFRESH_FINISHED;401 }402 }403 404 /**405 * 下拉刷新的**,使用下拉刷新的地方应该注册此**来获取刷新回调406 */407 public interface PullToRefreshListener {408 // 刷新时会去回调此方法,在方法内编写具体的刷新逻辑。注意此方法是在子线程中调用的, 可以不必另开线程来进行耗时操作409 void onRefresh();410 }411 }
--> 第三步, 写主布局:
1 <??> 2 <RelativeLayout ="http://schemas.android.com/apk/res/android" 3 ="http://schemas.android.com/tools" 4 android:layout_width="match_parent" 5 android:layout_height="match_parent" 6 tools:context=".MainActivity" > 7 8 <com.dragon.android.tofreshlayout.RefreshView 9 android:id="@+id/refreshable_view"10 android:layout_width="match_parent"11 android:layout_height="match_parent" >12 13 <ListView14 android:id="@+id/list_view"15 android:layout_width="match_parent"16 android:layout_height="match_parent" >17 </ListView>18 19 </com.dragon.android.tofreshlayout.RefreshView>20 21 </RelativeLayout>
activity_main
--> 最后, Java 代码添加 ListView 的数据:
package com.dragon.android.tofreshlayout;import android.os.Bundle;import android.os.SystemClock;import android.support.v7.app.AppCompatActivity;import android.webkit.WebView;import android.widget.ArrayAdapter;import android.widget.ListView;public class MainActivity extends AppCompatActivity { RefreshView refreshableView; ListView listView; ArrayAdapter<String> adapter; private WebView webView; private static int NUM = 30; String[] items = new String[NUM]; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); getSupportActionBar().hide(); for (int i = 0; i < items.length; i++) { items[i] = "列表项" + i; } refreshableView = (RefreshView) findViewById(R.id.refreshable_view); listView = (ListView) findViewById(R.id.list_view); adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, items); listView.setAdapter(adapter); refreshableView.setOnRefreshListener(new RefreshView.PullToRefreshListener() { @Override public void onRefresh() { SystemClock.sleep(3000); refreshableView.finishRefreshing(); } }, 0); }}
View Code
程序 Demo: 链接:http://pan.baidu.com/s/1ge6Llw3 密码:skna
***************其实还应该再封装的...*****************
原标题:Android之自定义控件
关键词:Android