android水平循环滚动控件使用详解

2023-09-18 15:06:05 75

本文实例为大家分享了android水平循环滚动控件的具体代码，供大家参考，具体内容如下

CycleScrollView.java

packagecom.example.test;

importandroid.content.Context;
importandroid.graphics.Rect;
importandroid.os.Handler;
importandroid.util.AttributeSet;
importandroid.view.GestureDetector;
importandroid.view.GestureDetector.OnGestureListener;
importandroid.view.MotionEvent;
importandroid.view.View;
importandroid.view.ViewGroup;
importandroid.widget.Scroller;

@SuppressWarnings("deprecation")
publicclassCycleScrollViewextendsViewGroupimplementsOnGestureListener{

staticfinalStringTAG="CycleScrollView";
ContextmContext;

/**
*Scrollvelocity.
*/
publicstaticfinallongSCROLL_VELOCITY=50;

/**
*Scrolloffset.
*/
publicstaticfinalintSCROLL_OFFSET=-1;

/**
*Touchdelay.
*/
publicstaticfinallongTOUCH_DELAYMILLIS=2000;

/**
*Flingduration.
*/
publicstaticfinalintFLING_DURATION=2000;

/**
*Filingmaxvelocityx.
*/
publicstaticfinalintMAX_VELOCITY_X=1000;

privateGestureDetectordetector;
privateHandlermHandler;
privateScrollermScroller;

/**
*CallbackinterfaceadapterandOnItemClick.
*/
privateCycleScrollAdaptermAdapter;
privateOnItemClickListenermOnItemClickListener;

/**
*Scrollindex
*/
privateintmPreIndex;
privateintmCurrentIndex;
privateintmNextIndex;
privateViewmCurrentView;
privateViewmPreView;
privateViewmNextView;

privatefloatmLastMotionX;

//ThereLayoutisfalsecannotinvokeonLayout.
privatebooleanreLayout=false;

//Iftheitemcountmorethanscreenthatcanscroll.
privatebooleancanScroll=false;

//Aflagforswitchcurrentview.
privatebooleanmCurrentViewAtLeft=true;

//Flingdistance.
privateintmFlingX=0;

privatebooleanisMoveAction=false;

privateintdefaultItemY=10;

privateintmaxItemCount=7;

privateintinitItemX=20;

/**
*Thescreenwidth.
*/
privateintscreenWidth;

/**
*Itemviewheight.
*/
privateintitemHeight;

/**
*Itemviewwidth.
*/
privateintitemWidth;

/**
*Itemviewlayoutx.
*/
privateintitemX=getInitItemX();

/**
*Itemviewlayouty.
*/
privateintitemY=defaultItemY;

//Autoscrollviewtask.
privatefinalRunnablemScrollTask=newRunnable(){

@Override
publicvoidrun(){
if(canScroll){
scrollView(SCROLL_OFFSET);
mHandler.postDelayed(this,SCROLL_VELOCITY);//Loopself.
}
}
};

publicCycleScrollView(Contextcontext){
super(context);
onCreate(context);
}

publicCycleScrollView(Contextcontext,AttributeSetattrs){
super(context,attrs);
onCreate(context);
}

publicCycleScrollView(Contextcontext,AttributeSetattrs,intdefStyle){
super(context,attrs,defStyle);
onCreate(context);
}

privatevoidonCreate(Contextcontext){
mContext=context;
detector=newGestureDetector(this);
mHandler=newHandler();
mScroller=newScroller(context);
}

/**
*Createscrollindex.
*/
publicvoidcreateIndex(){
if(canScroll){
mPreIndex=maxItemCount-1;
mCurrentIndex=0;
mNextIndex=1;
mPreView=getChildAt(mPreIndex);
mCurrentView=getChildAt(mCurrentIndex);
mNextView=getChildAt(mNextIndex);
}
}

/**
*Setitemclickcallback.
*
*@paramonItemClickListener
*Thecallback
*/
publicvoidsetOnItemClickListener(OnItemClickListeneronItemClickListener){
mOnItemClickListener=onItemClickListener;
}

/**
*SetitemAdapterforaddItemandbindItem.
*
*@paramitemAdapter
*/
publicvoidsetAdapter(CycleScrollAdapteradapter){
mAdapter=adapter;
}

/**
*Startautoscroll.
*/
publicvoidstartScroll(){
if(canScroll){
mHandler.post(mScrollTask);
}
}

/**
*Stopautoscrollandfilingscrolltask.
*/
publicvoidstopScroll(){
mHandler.removeCallbacks(mScrollTask);
}

/**
*Delaystartautoscrolltask.
*/
publicvoiddelayStartScroll(){
if(canScroll){
mHandler.postDelayed(mScrollTask,TOUCH_DELAYMILLIS);
}
}

@Override
protectedvoidonMeasure(intwidthMeasureSpec,intheightMeasureSpec){
super.onMeasure(widthMeasureSpec,heightMeasureSpec);
intcount=this.getChildCount();
for(inti=0;imaxItemCount-1){
mNextIndex=0;
}
mCurrentView=getChildAt(mCurrentIndex);
mPreView=getChildAt(mPreIndex);
mNextView=getChildAt(mNextIndex);
mCurrentViewAtLeft=!mCurrentViewAtLeft;
}
}

/**
*Currenteventismovetoright,ifcurrentviewatleftswitchcurrent
*viewtoright.
*/
privatevoidswitchCurrentViewToRight(){
if(mCurrentViewAtLeft){
mNextIndex=mCurrentIndex;
mCurrentIndex=mPreIndex;
mPreIndex--;
if(mPreIndex<0){
mPreIndex=maxItemCount-1;
}
mCurrentView=getChildAt(mCurrentIndex);
mPreView=getChildAt(mPreIndex);
mNextView=getChildAt(mNextIndex);
mCurrentViewAtLeft=!mCurrentViewAtLeft;
}
}

/**
*Currenteventismovetoleft,ifcurrentviewmoveoutofscreenmovethe
*currentviewtorightandreBindtheitemchangeindex.
*/
privatevoidmoveToNext(){
if(mCurrentView.getRight()<0){
mCurrentView.layout(mPreView.getLeft()+getItemMargin(),
getItemY(),mPreView.getLeft()+getItemMargin()
+getItemWidth(),getItemY()+getItemHeight());

if(mCurrentView.getTag()!=null){
intlistIndex=(Integer)mCurrentView.getTag();
intindex=(listIndex+maxItemCount)%mAdapter.getCount();
mAdapter.bindView(mCurrentView,mAdapter.get(index));
mCurrentView.setTag(index);
}

mPreIndex=mCurrentIndex;
mCurrentIndex=mNextIndex;
mNextIndex++;
if(mNextIndex>maxItemCount-1){
mNextIndex=0;
}
mCurrentView=getChildAt(mCurrentIndex);
mPreView=getChildAt(mPreIndex);
mNextView=getChildAt(mNextIndex);
moveToNext();
}
}

/**
*Currenteventismovetoright,ifcurrentviewmoveoutofscreenmove
*thecurrentviewtoleftandreBindtheitemchangeindex.
*/
privatevoidmoveToPre(){
if(mCurrentView.getLeft()>getScreenWidth()){
mCurrentView.layout(mNextView.getLeft()-getItemMargin(),
getItemY(),mNextView.getLeft()-getItemMargin()
+getItemWidth(),getItemY()+getItemHeight());

if(mCurrentView.getTag()!=null){
intlistIndex=(Integer)mCurrentView.getTag();
intindex=(listIndex-maxItemCount+mAdapter.getCount())
%mAdapter.getCount();
mAdapter.bindView(mCurrentView,mAdapter.get(index));
mCurrentView.setTag(index);
}

mNextIndex=mCurrentIndex;
mCurrentIndex=mPreIndex;
mPreIndex--;
if(mPreIndex<0){
mPreIndex=maxItemCount-1;
}
mCurrentView=getChildAt(mCurrentIndex);
mPreView=getChildAt(mPreIndex);
mNextView=getChildAt(mNextIndex);
moveToPre();
}
}

@Override
publicbooleanonDown(MotionEvente){
returntrue;
}

@Override
publicvoidonShowPress(MotionEvente){
}

@Override
publicbooleanonSingleTapUp(MotionEvente){
returnfalse;
}

@Override
publicbooleanonScroll(MotionEvente1,MotionEvente2,floatdistanceX,
floatdistanceY){
returnfalse;
}

@Override
publicvoidonLongPress(MotionEvente){
}

publicintgetMaxItemCount(){
returnmaxItemCount;
}

publicvoidsetMaxItemCount(intmaxItemCount){
this.maxItemCount=maxItemCount;
}

publicvoidsetReLayout(booleanreLayout){
this.reLayout=reLayout;
}

publicvoidsetCanScroll(booleancanScroll){
this.canScroll=canScroll;
}

publicintgetItemX(){
returnitemX;
}

publicvoidsetItemX(intitemX){
this.itemX=itemX;
}

publicintgetItemY(){
returnitemY;
}

publicvoidsetItemY(intitemY){
this.itemY=itemY;
}

publicintgetItemWidth(){
returnitemWidth;
}

publicvoidsetItemWidth(intitemWidth){
this.itemWidth=itemWidth;
}

publicintgetItemHeight(){
returnitemHeight;
}

publicvoidsetItemHeight(intitemHeight){
this.itemHeight=itemHeight;
}

publicintgetItemMargin(){
return(screenWidth-itemWidth*(maxItemCount-1)-initItemX*2)/(maxItemCount-2)+itemWidth;
}

publicintgetScreenWidth(){
returnscreenWidth;
}

publicvoidsetScreenWidth(intscreenWidth){
this.screenWidth=screenWidth;
}

publicintgetInitItemX(){
returninitItemX;
}

publicvoidsetInitItemX(intinitItemX){
this.initItemX=initItemX;
}

/**
*Theinterfaceforitemclickcallback.
*/
interfaceOnItemClickListener{
publicbooleanonItemClick(intposition);
}

}

CycleScrollAdapter.java

packagecom.example.test;

importjava.util.List;

importandroid.app.Activity;
importandroid.content.Context;
importandroid.util.DisplayMetrics;
importandroid.view.View;

publicabstractclassCycleScrollAdapter{

privateListlist;
privateCycleScrollViewmCycleScrollView;
ContextmContext;

/**
*InitialCycleScrollAdapterbindlisttoview.
*
*@paramlist
*Thelistdata.
*@paramcycleScrollView
*TheCycleScrollView.
*@paramcontext
*TheContext.
*/
publicCycleScrollAdapter(Listlist,CycleScrollViewcycleScrollView,
Contextcontext){
this.list=list;
mContext=context;
mCycleScrollView=cycleScrollView;
mCycleScrollView.setAdapter(this);
GetScreenWidthPixels();
initView(list);
}

/**
*Getscreenwidthpixels.
*/
privatevoidGetScreenWidthPixels(){
DisplayMetricsdm=newDisplayMetrics();
Activitya=(Activity)mContext;
a.getWindowManager().getDefaultDisplay().getMetrics(dm);
mCycleScrollView.setScreenWidth(dm.widthPixels);
}

/**
*Bindlisttoview.
*
*@paramlist
*Thelistdata.
*/
protectedvoidinitView(Listlist){
if(list==null||list.size()==0){
return;
}

//ClearallviewfromViewGroupatfirst.
mCycleScrollView.removeAllViewsInLayout();

//Looplist.
for(inti=0;i=mCycleScrollView.getMaxItemCount()){
mCycleScrollView.setCanScroll(true);
}else{
mCycleScrollView.setCanScroll(false);
}

/**
*IflistcountmorethanMaxItemCountreBuildindex.
*/
mCycleScrollView.createIndex();
}

/**
*Getlistsize.
*
*@returnThelistsize.
*/
publicintgetCount(){
returnlist.size();
}

/**
*Returnstheelementatthespecifiedlocationinthis
*
*@paramindex
*theindexoftheelementtoreturn.
*@returntheelementatthespecifiedlocation.
*/
publicTget(intindex){
returnlist.get(index);
}

/**
*Addsthespecifiedobjectattheendofthisandrefreshview.
*
*@paramt
*theobjecttoadd.
*/
publicvoidaddItem(Tt){
list.add(t);
initView(list);
}

/**
*Removesthefirstoccurrenceofthespecifiedobjectfromthisand
*refreshview.
*
*@paramt
*theobjecttoremove.
*/
publicvoidremoveItem(Tt){
list.remove(t);
initView(list);
}

/**
*Addthespecifiedviewtotheindex.
*
*@paramt
*Thedatatoadd.
*@paramindex
*theindex.
*/
privatevoidadd(Tt,intindex){
Viewview=getView(t);
ComputeItemSize(view);
mCycleScrollView.addView(view);
view.setTag(index);
}

/**
*Ifitemsizeisnullcomputeitemsize.
*
*@paramview
*theitemview.
*/
privatevoidComputeItemSize(Viewview){
if(mCycleScrollView.getItemWidth()==0
||mCycleScrollView.getItemHeight()==0){
intw=View.MeasureSpec.makeMeasureSpec(0,
View.MeasureSpec.UNSPECIFIED);
inth=View.MeasureSpec.makeMeasureSpec(0,
View.MeasureSpec.UNSPECIFIED);
view.measure(w,h);
intheight=view.getMeasuredHeight();
intwidth=view.getMeasuredWidth();
mCycleScrollView.setItemHeight(height);
mCycleScrollView.setItemWidth(width);
}
}

/**
*Getitemview.
*
*@paramt
*thedataneedbindtoview.
*@returntheview.
*/
publicabstractViewgetView(Tt);

/**
*Bindtheitemtoview.
*
*@paramchild
*theitemviewneedbind.
*@paramt
*theitem.
*/
publicabstractvoidbindView(Viewchild,Tt);
}

以上两个是核心类，下面是测试代码。

实现CycleScrollAdapter

AppCycleScrollAdapter.java绑定视图和应用数据

packagecom.example.test;

importjava.util.List;

importandroid.content.Context;
importandroid.content.pm.PackageInfo;
importandroid.view.View;
importandroid.widget.ImageView;
importandroid.widget.TextView;

publicclassAppCycleScrollAdapterextendsCycleScrollAdapter{

publicAppCycleScrollAdapter(Listlist,
CycleScrollViewcycleScrollView,Contextcontext){
super(list,cycleScrollView,context);
}

@Override
protectedvoidinitView(Listlist){
super.initView(list);
}

@Override
publicvoidbindView(Viewchild,PackageInfopi){
ImageViewimage=(ImageView)child.findViewById(R.id.item_image);
TextViewtext=(TextView)child.findViewById(R.id.item_text);
image.setImageDrawable(pi.applicationInfo.loadIcon(mContext
.getPackageManager()));
text.setText(pi.applicationInfo.loadLabel(mContext.getPackageManager()));
}

@Override
publicViewgetView(PackageInfopi){
Viewview=View.inflate(mContext,R.layout.view_item,null);
//inflateAPPiconview
ImageViewimage=(ImageView)view.findViewById(R.id.item_image);
//inflateAPPnameview
TextViewtext=(TextView)view.findViewById(R.id.item_text);
image.setImageDrawable(pi.applicationInfo.loadIcon(mContext
.getPackageManager()));
text.setText(pi.applicationInfo.loadLabel(mContext.getPackageManager()));
returnview;
}
}

入口Activity

packagecom.example.test;


importjava.util.List;


importandroid.app.Activity;
importandroid.content.pm.PackageInfo;
importandroid.os.Bundle;
importandroid.view.Menu;

publicclassMainActivityextendsActivity{

privateCycleScrollViewmCycleScrollView;
privateAppCycleScrollAdaptermAdapter;

@Override
publicvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

mCycleScrollView=((CycleScrollView)this.findViewById(R.id.cycle_scroll_view));

/**
*GetAPPlistandsortbyupdatetime.
*/
Listlist=this.getPackageManager()
.getInstalledPackages(0);

mAdapter=newAppCycleScrollAdapter(list,mCycleScrollView,this);

}



@Override
publicbooleanonCreateOptionsMenu(Menumenu){
getMenuInflater().inflate(R.menu.activity_main,menu);
returntrue;
}

}

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android水平循环滚动控件使用详解

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