原理：就是动态改变ScrollView header的margin实现
主要的代码：
http://blog.csdn.net/swust_chenpeng/article/details/39289721
public class RefreshScrollView extends ScrollView {
private final static int SCROLL_DURATION = 400;
private final static float OFFSET_RADIO = 1.8f;
private int headerHeight = 0;
private boolean enableRefresh = true;
private boolean refreshing = false;
private int lastY;
private Scroller scroller = null;
private OnRefreshScrollViewListener listener = null;
private LinearLayout scrollContainer = null;
private ScrollViewHeader headerView = null;
public RefreshScrollView(Context context) {
super(context);
// TODO Auto-generated constructor stub
if (!isInEditMode()) {
initView(context);
}
}
public RefreshScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
if (!isInEditMode()) {
initView(context);
}
}
public RefreshScrollView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
if (!isInEditMode()) {
initView(context);
}
}
/**
* 初始化view
*/
private void initView(Context context) {
scroller = new Scroller(context);
headerView = new ScrollViewHeader(context);
LinearLayout.LayoutParams headerViewParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
//scrollview只允许嵌套一个子布局
scrollContainer = new LinearLayout(context);
scrollContainer.addView(headerView, headerViewParams);
scrollContainer.setOrientation(LinearLayout.VERTICAL);
addView(scrollContainer);
//提前获取headerView的高度
headerView.getViewTreeObserver().addOnGlobalLayoutListener(
new OnGlobalLayoutListener() {
@SuppressWarnings("deprecation")
@Override
public void onGlobalLayout() {
// TODO Auto-generated method stub
headerHeight = headerView.getHeight();
headerView.updateMargin(-headerHeight);
headerView.getViewTreeObserver()
.removeGlobalOnLayoutListener(this);
}
});
}
/**
* 设置内容区域
*
* @param context
* @param resId
*/
public void setupContainer(Context context, View containerView) {
scrollContainer.addView(containerView);
}
/**
* 设置scroll是否可以刷新
*
* @param enableRefresh
*/
public void setEnableRefresh(boolean enableRefresh) {
this.enableRefresh = enableRefresh;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
// TODO Auto-generated method stub
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
lastY = (int) ev.getY();
break;
case MotionEvent.ACTION_MOVE:
int deltY = (int) (ev.getY() - lastY);
lastY = (int) ev.getY();
Logger.d("getScrollY:" + getScrollY());
if (getScrollY() == 0
&& (deltY > 0 || headerView.getTopMargin() > -headerHeight)) {
updateHeader(deltY/OFFSET_RADIO);
return true;
}
break;
default:
//这里没有使用action_up的原因是，可能会受到viewpager的影响接收到action_cacel事件
Logger.d("ev.getAction: " +ev.getAction());
if (getScrollY() == 0) {
Logger.d("topMargin():" + headerView.getTopMargin());
if (headerView.getTopMargin() > 0 && enableRefresh && !refreshing) {
refreshing = true;
headerView.setState(ScrollViewHeader.STATE_REFRESHING);
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
if(listener != null) {
listener.onRefresh();
refreshing = false;
ShowUtils.shortShow("更新成功");
resetHeaderView();
}
}
}, 3000);
}
Logger.d("resetHeaderView...");
resetHeaderView();
}
break;
}
return super.onTouchEvent(ev);
}
/**
* 更新headerview的高度,同时更改状态
*
* @param deltY
*/
public void updateHeader(float deltY) {
int currentMargin = (int) (headerView.getTopMargin() + deltY);
headerView.updateMargin(currentMargin);
if(enableRefresh && !refreshing) {
if (currentMargin > 0) {
headerView.setState(ScrollViewHeader.STATE_READY);
} else {
headerView.setState(ScrollViewHeader.STATE_NORMAL);
}
}
}
/**
* 重置headerview的高度
*/
public void resetHeaderView() {
int margin = headerView.getTopMargin();
if(margin == -headerHeight) {
return ;
}
if(margin < 0 && refreshing) {
//当前已经在刷新，又重新进行拖动,但未拖满,不进行操作
return ;
}
int finalMargin = 0;
if(margin <= 0 && !refreshing) {
finalMargin = headerHeight;
}
Logger.d("margin: " + margin);
Logger.d("finalMargin: " + finalMargin);
//松开刷新，或者下拉刷新，又松手，没有触发刷新
scroller.startScroll(0, -margin, 0, finalMargin + margin, SCROLL_DURATION);
invalidate();
}
/**
* 开始刷新
*/
public void startRefresh() {
refreshing = true;
headerView.setState(ScrollViewHeader.STATE_REFRESHING);
if(listener != null) {
Logger.d("xxx: " + headerHeight);
scroller.startScroll(0, 0, 0, headerHeight, SCROLL_DURATION);
invalidate();
listener.onRefresh();
}
}
/**
* 停止刷新
*/
public void stopRefresh() {
if(refreshing) {
refreshing = false;
resetHeaderView();
}
}
@Override
public void computeScroll() {
// TODO Auto-generated method stub
if(scroller.computeScrollOffset()) {
Logger.d("getCurrY: " + scroller.getCurrY());
headerView.updateMargin(-scroller.getCurrY());
//继续重绘
postInvalidate();
}
super.computeScroll();
}
public void setOnRefreshScrollViewListener(OnRefreshScrollViewListener listener) {
this.listener = listener;
}
public interface OnRefreshScrollViewListener {
public void onRefresh();
}
}
代码其实还是比较容易，但是但是，自己还是花了很多时间，脑袋瓜不够灵活呀...
下面是ScrollViewHeader的代码：
public class ScrollViewHeader extends RelativeLayout {
public final static int STATE_NORMAL = 0;
public final static int STATE_READY = 1;
public final static int STATE_REFRESHING = 2;
private final int ROTATE_ANIM_DURATION = 180;
private int topMargin = 0;
private int state = STATE_NORMAL;
private TextView refreshTv = null;
private TextView refreshTimeTv = null;
private ProgressBar refreshProgress = null;
private ImageView refreshArrow = null;
private Animation animationUp = null;
private Animation animationDown = null;
public ScrollViewHeader(Context context) {
super(context);
// TODO Auto-generated constructor stub
if(!isInEditMode())
initView(context);
}
public ScrollViewHeader(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
if(!isInEditMode())
initView(context);
}
public ScrollViewHeader(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
if(!isInEditMode())
initView(context);
}
/**
* 初始化相关的view
*/
public void initView(Context context) {
animationDown = new RotateAnimation(-180f, 0, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
animationDown.setDuration(ROTATE_ANIM_DURATION);
animationDown.setFillAfter(true);
animationUp = new RotateAnimation(0, -180f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
animationUp.setDuration(ROTATE_ANIM_DURATION);
animationUp.setFillAfter(true);
setPadding(10, 25, 10, 25);
View view = LayoutInflater.from(context).inflate(R.layout.scrollview_header, this, true);
refreshTv = (TextView) view.findViewById(R.id.refresh_text);
refreshTimeTv = (TextView) view.findViewById(R.id.refresh_time);
refreshProgress = (ProgressBar) view.findViewById(R.id.refresh_progress);
refreshArrow = (ImageView) view.findViewById(R.id.refresh_arrow);
}
/**
* 设置scrollviewHeader的状态
* @param state
*/
public void setState(int state) {
if(this.state == state) {
return ;
}
switch (state) {
case STATE_NORMAL:
refreshTv.setText("下拉刷新");
refreshArrow.setVisibility(View.VISIBLE);
refreshProgress.setVisibility(View.INVISIBLE);
if(this.state == STATE_READY) {
refreshArrow.startAnimation(animationDown);
} else if(this.state == STATE_REFRESHING) {
refreshArrow.clearAnimation();
}
break;
case STATE_READY:
refreshTv.setText("松开刷新");
refreshArrow.setVisibility(View.VISIBLE);
refreshProgress.setVisibility(View.INVISIBLE);
refreshArrow.startAnimation(animationUp);
break;
case STATE_REFRESHING:
refreshTv.setText("正在加载...");
refreshProgress.setVisibility(View.VISIBLE);
refreshArrow.clearAnimation();
refreshArrow.setVisibility(View.INVISIBLE);
break;
default:
break;
}
this.state = state;
}
/**
* 更新header的margin
* @param margin
*/
public void updateMargin(int margin) {
//这里用Linearlayout的原因是Headerview的父控件是scrollcontainer是一个linearlayout
LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) this.getLayoutParams();
params.topMargin = margin;
topMargin = margin;
setLayoutParams(params);
}
/**
* 获取header的margin
* @return
*/
public int getTopMargin() {
return topMargin;
}
}
header的布局文件，scrollview_header
<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android" >
<LinearLayout
android:id="@+id/refresh_des"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:gravity="center"
android:orientation="vertical" >
<TextView
android:id="@+id/refresh_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="下拉刷新" />
<TextView
android:id="@+id/refresh_time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="5分钟前更新" />
</LinearLayout>
<ProgressBar
android:id="@+id/refresh_progress"
android:layout_width="30dip"
android:layout_height="30dip"
android:layout_centerVertical="true"
android:layout_marginRight="10dip"
android:layout_toLeftOf="@id/refresh_des"
android:visibility="invisible" />
<ImageView
android:id="@+id/refresh_arrow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginRight="10dip"
android:layout_toLeftOf="@id/refresh_des"
android:src="@drawable/arrow" />
</merge>
好了，相关的源码就只有3个文件...
时间： 2024-10-06 00:45:04