【移动应用开发技术】banner广告及view pager 的小圆点指示器

【移动应用开发技术】banner广告及viewpager的小圆点指示器

一、主界面packagecom.example.t;importandroid.app.Activity;importandroid.os.Bundle;importandroid.support.v4.view.ViewPager;importandroid.support.v4.view.ViewPager.OnPageChangeListener;publicclassMainActivityextendsActivityimplementsOnPageChangeListener{

privateCirclePageIndicatorindicator;

privateViewPagerviewpager;

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

initview();

}

privatevoidinitview(){

viewpager=(ViewPager)findViewById(R.id.viewpager);

indicator=(CirclePageIndicator)findViewById(R.id.indicator);

indicator.setStrokeWidth(0);

indicator.setPageCircleColor(0xFFFFFFFF);

viewpager.setAdapter(newMyadapter(this));

indicator.setViewPager(viewpager);

indicator.setOnPageChangeListener(this);

}

@Override

publicvoidonPageScrollStateChanged(intarg0){

}

@Override

publicvoidonPageScrolled(intarg0,floatarg1,intarg2){

}

@Override

publicvoidonPageSelected(intarg0){

}}二、广告适配器packagecom.example.t;importandroid.content.Context;importandroid.support.v4.view.PagerAdapter;importandroid.support.v4.view.ViewPager.LayoutParams;importandroid.view.View;importandroid.view.ViewGroup;importandroid.widget.ImageView;importandroid.widget.ImageView.ScaleType;publicclassMyadapterextendsPagerAdapter{

privateContextcontext;

privateint[]p_w_picpaths;

publicMyadapter(Contextcontext){

this.context=context;

p_w_picpaths=newint[]{R.drawable.default_img_mid,R.drawable.default_img_mid,R.drawable.default_img_mid};

}

@Override

publicintgetCount(){

returnp_w_picpaths.length;

}

//判断View和Object是否为同一个View

@Override

publicbooleanisViewFromObject(Viewview,Objectobject){

returnview==object;

}

//控制当某个View不需要的时候的回收处理

@Override

publicvoiddestroyItem(ViewGroupcontainer,intposition,Objectobject){

container.removeView((View)object);

}

//实例化Item：即得到每个View

@Override

publicObjectinstantiateItem(ViewGroupcontainer,intposition){

ImageViewiv=newImageView(context);

iv.setScaleType(ScaleType.CENTER_CROP);

android.view.ViewGroup.LayoutParamsparams=newandroid.view.ViewGroup.LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT);

iv.setLayoutParams(params);

iv.setImageResource(p_w_picpaths[position]);

container.addView(iv);

returniv;

}}三、小圆点指示器packagecom.example.t;importstaticandroid.graphics.Paint.ANTI_ALIAS_FLAG;importstaticandroid.widget.LinearLayout.HORIZONTAL;importandroid.content.Context;importandroid.graphics.Canvas;importandroid.graphics.Paint;importandroid.graphics.Paint.Style;importandroid.os.Parcel;importandroid.os.Parcelable;importandroid.support.v4.view.MotionEventCompat;importandroid.support.v4.view.ViewConfigurationCompat;importandroid.support.v4.view.ViewPager;importandroid.support.v4.view.ViewPager.OnPageChangeListener;importandroid.util.AttributeSet;importandroid.view.MotionEvent;importandroid.view.View;importandroid.view.ViewConfiguration;/**

*@describeviewpager的小圆点指示器

*/publicclassCirclePageIndicatorextendsViewimplementsOnPageChangeListener{

privatestaticfinalintINVALID_POINTER=-1;

privatefloatmRadius;

privatefinalPaintmPaintPageFill=newPaint(ANTI_ALIAS_FLAG);

privatefinalPaintmPaintStroke=newPaint(ANTI_ALIAS_FLAG);

privatefinalPaintmPaintFill=newPaint(ANTI_ALIAS_FLAG);

privateViewPagermViewPager;

privateViewPager.OnPageChangeListenermListener;

privateintmCurrentPage;

privateintmSnapPage;

privatefloatmPageOffset;

privateintmScrollState;

privateintmOrientation;

privatebooleanmCentered;

privatebooleanmSnap;

privateintmTouchSlop;

privatefloatmLastMotionX=-1;

privateintmActivePointerId=INVALID_POINTER;

privatebooleanmIsDragging;

privateContextcontext;

publicCirclePageIndicator(Contextcontext){

super(context);

this.context=context;

init(context);

}

publicCirclePageIndicator(Contextcontext,AttributeSetattrs){

super(context,attrs);

init(context);

}

privatevoidinit(Contextcontext){

mCentered=true;

mOrientation=0;

mPaintPageFill.setStyle(Style.FILL);

mPaintPageFill.setColor(0x00000000);

mPaintStroke.setStyle(Style.STROKE);

mPaintStroke.setColor(0xFFFF6600);

mPaintStroke.setStrokeWidth(getResources().getDimension(R.dimen.indicator_stroke_width));

mPaintFill.setStyle(Style.FILL);

mPaintFill.setColor(0xFFFF6600);

mRadius=getResources().getDimension(R.dimen.indicator_radius);

mSnap=false;

finalViewConfigurationconfiguration=ViewConfiguration.get(context);

mTouchSlop=ViewConfigurationCompat.getScaledPagingTouchSlop(configuration);

}

publicvoidsetRadius(intdpValue){

floatscale=context.getResources().getDisplayMetrics().density;

mRadius=(int)(dpValue*scale+0.5f);

invalidate();

}

publicfloatfraction;

privatefloatparseRadiusIfNeed(floatpageFillRadius){

returnfraction==0?pageFillRadius:pageFillRadius+pageFillRadius/fraction;

}

@Override

protectedvoidonDraw(Canvascanvas){

super.onDraw(canvas);

if(mViewPager==null){

return;

}

finalintcount=mViewPager.getAdapter().getCount();

if(count==0){

return;

}

if(mCurrentPage>=count){

setCurrentItem(count-1);

return;

}

intlongSize;

intlongPaddingBefore;

intlongPaddingAfter;

intshortPaddingBefore;

if(mOrientation==HORIZONTAL){

longSize=getWidth();

longPaddingBefore=getPaddingLeft();

longPaddingAfter=getPaddingRight();

shortPaddingBefore=getPaddingTop();

}else{

longSize=getHeight();

longPaddingBefore=getPaddingTop();

longPaddingAfter=getPaddingBottom();

shortPaddingBefore=getPaddingLeft();

}

finalfloatthreeRadius=mRadius*5;

finalfloatshortOffset=shortPaddingBefore+mRadius;

floatlongOffset=longPaddingBefore+mRadius;

if(mCentered){

longOffset+=((longSize-longPaddingBefore-longPaddingAfter)/2.0f)-((count*threeRadius)/2.0f);

}

floatdX;

floatdY;

floatpageFillRadius=mRadius;

if(mPaintStroke.getStrokeWidth()>0){

pageFillRadius-=mPaintStroke.getStrokeWidth()*1.5f;//实心圆的半径

}

//Drawstrokedcircles

for(intiLoop=0;iLoop<count;iLoop++){

floatdrawLong=longOffset+(iLoop*threeRadius);

if(mOrientation==HORIZONTAL){

dX=drawLong;

dY=shortOffset;

}else{

dX=shortOffset;

dY=drawLong;

}

//Onlypaintfillifnotcompletelytransparent

if(mPaintPageFill.getAlpha()>0){

canvas.drawCircle(dX,dY,pageFillRadius,mPaintPageFill);

}

//Onlypaintstrokeifastrokewidthwasnon-zero

if(pageFillRadius!=mRadius){

canvas.drawCircle(dX,dY,mRadius,mPaintStroke);

}

}

//Drawthefilledcircleaccordingtothecurrentscroll

floatcx=(mSnap?mSnapPage:mCurrentPage)*threeRadius;

if(!mSnap){

cx+=mPageOffset*threeRadius;

}

if(mOrientation==HORIZONTAL){

dX=longOffset+cx;

dY=shortOffset;

}else{

dX=shortOffset;

dY=longOffset+cx;

}

canvas.drawCircle(dX,dY,parseRadiusIfNeed(pageFillRadius),mPaintFill);

}

publicbooleanonTouchEvent(android.view.MotionEventev){

if(super.onTouchEvent(ev)){

returntrue;

}

if((mViewPager==null)||(mViewPager.getAdapter().getCount()==0)){

returnfalse;

}

finalintaction=ev.getAction()&MotionEventCompat.ACTION_MASK;

switch(action){

caseMotionEvent.ACTION_DOWN:

mActivePointerId=MotionEventCompat.getPointerId(ev,0);

mLastMotionX=ev.getX();

break;

caseMotionEvent.ACTION_MOVE:{

finalintactivePointerIndex=MotionEventCompat.findPointerIndex(ev,mActivePointerId);

finalfloatx=MotionEventCompat.getX(ev,activePointerIndex);

finalfloatdeltaX=x-mLastMotionX;

if(!mIsDragging){

if(Math.abs(deltaX)>mTouchSlop){

mIsDragging=true;

}

}

if(mIsDragging){

mLastMotionX=x;

if(mViewPager.isFakeDragging()||mViewPager.beginFakeDrag()){

mViewPager.fakeDragBy(deltaX);

}

}

break;

}

caseMotionEvent.ACTION_CANCEL:

caseMotionEvent.ACTION_UP:

if(!mIsDragging){

finalintcount=mViewPager.getAdapter().getCount();

finalintwidth=getWidth();

finalfloathalfWidth=width/2f;

finalfloatsixthWidth=width/6f;

if((mCurrentPage>0)&&(ev.getX()<halfWidth-sixthWidth)){

if(action!=MotionEvent.ACTION_CANCEL){

mViewPager.setCurrentItem(mCurrent1);

}

returntrue;

}elseif((mCurrentPage<count-1)&&(ev.getX()>halfWidth+sixthWidth)){

if(action!=MotionEvent.ACTION_CANCEL){

mViewPager.setCurrentItem(mCurrentPage+1);

}

returntrue;

}

}

mIsDragging=false;

mActivePointerId=INVALID_POINTER;

if(mViewPager.isFakeDragging())

mViewPager.endFakeDrag();

break;

caseMotionEventCompat.ACTION_POINTER_DOWN:{

finalintindex=MotionEventCompat.getActionIndex(ev);

mLastMotionX=MotionEventCompat.getX(ev,index);

mActivePointerId=MotionEventCompat.getPointerId(ev,index);

break;

}

caseMotionEventCompat.ACTION_POINTER_UP:

finalintpointerIndex=MotionEventCompat.getActionIndex(ev);

finalintpointerId=MotionEventCompat.getPointerId(ev,pointerIndex);

if(pointerId==mActivePointerId){

finalintnewPointerIndex=pointerIndex==0?1:0;

mActivePointerId=MotionEventCompat.getPointerId(ev,newPointerIndex);

}

mLastMotionX=MotionEventCompat.getX(ev,MotionEventCompat.findPointerIndex(ev,mActivePointerId));

break;

}

returntrue;

}

publicvoidsetViewPager(ViewPagerview){

if(mViewPager==view){

return;

}

if(mViewPager!=null){

mViewPager.setOnPageChangeListener(null);

}

if(view.getAdapter()==null){

thrownewIllegalStateException("ViewPagerdoesnothaveadapterinstance.");

}

mViewPager=view;

mViewPager.setOnPageChangeListener(this);

invalidate();

}

publicvoidsetViewPager(ViewPagerview,intinitialPosition){

setViewPager(view);

setCurrentItem(initialPosition);

}

publicvoidsetCurrentItem(intitem){

if(mViewPager==null){

thrownewIllegalStateException("ViewPagerhasnotbeenbound.");

}

mViewPager.setCurrentItem(item);

mCurrentPage=item;

invalidate();

}

publicvoidnotifyDataSetChanged(){

invalidate();

}

@Override

publicvoidonPageScrollStateChanged(intstate){

mScrollState=state;

if(mListener!=null){

mListener.onPageScrollStateChanged(state);

}

}

@Override

publicvoidonPageScrolled(intposition,floatpositionOffset,intpositionOffsetPixels){

mCurrentPage=position;

mPageOffset=positionOffset;

invalidate();

if(mListener!=null){

mListener.onPageScrolled(position,positionOffset,positionOffsetPixels);

}

}

@Override

publicvoidonPageSelected(intposition){

if(mSnap||mScrollState==ViewPager.SCROLL_STATE_IDLE){

mCurrentPage=position;

mSnapPage=position;

invalidate();

}

if(mListener!=null){

mListener.onPageSelected(position);

}

}

publicvoidsetOnPageChangeListener(ViewPager.OnPageChangeListenerlistener){

mListener=listener;

}

/**

*设置圆边框的颜色

*/

publicvoidsetStrokeColor(intcolor){

try{

mPaintStroke.setColor(color);

}catch(Exceptione){

mPaintStroke.setColor(0xFFFF6600);

e.printStackTrace();

}

}

/**

*设置中心圆的颜色

*

*@paramcolor

*/

publicvoidsetCircleColor(intcolor){

try{

mPaintFill.setColor(color);

}catch(Exceptione){

mPaintFill.setColor(0xFFFF6600);

e.printStackTrace();

}

}

publicvoidsetPageCircleColor(intcolor){

try{

mPaintPageFill.setColor(color);

}catch(Exceptione){

mPaintPageFill.setColor(0x00000000);

e.printStackTrace();

}

}

publicvoidsetStrokeWidth(floatwidth){

mPaintStroke.setStrokeWidth(width);

}

/*

*(non-Javadoc)

*

*@seeandroid.view.View#onMeasure(int,int)

*/

@Override

protectedvoidonMeasure(intwidthMeasureSpec,intheightMeasureSpec){

if(mOrientation==HORIZONTAL){

setMeasuredDimension(measureLong(widthMeasureSpec),measureShort(heightMeasureSpec));

}else{

setMeasuredDimension(measureShort(widthMeasureSpec),measureLong(heightMeasureSpec));

}

}

/**

*Determinesthewidthofthisview

*

*@parammeasureSpec

*

AmeasureSpecpackedintoanint

*@returnThewidthoftheview,honoringconstraintsfrommeasureSpec

*/

privateintmeasureLong(intmeasureSpec){

intresult;

intspecMode=MeasureSpec.getMode(measureSpec);

intspecSize=MeasureSpec.getSize(measureSpec);

if((specMode==MeasureSpec.EXACTLY)||(mViewPager==null)){

//Weweretoldhowbigtobe

result=specSize;

}else{

//Calculatethewidthaccordingtheviewscount

finalintcount=mViewPager.getAdapter().getCount();

result=(int)(getPaddingLeft()+getPaddingRight()+(count*2*mRadius)+(count-1)*mRadius*4+1);

//RespectAT_MOSTvalueifthatwaswhatiscalledforbymeasureSpec

if(specMode==MeasureSpec.AT_MOST){

result=Math.min(result,specSize);

}

}

returnresult;

}

/**

*Determinestheheightofthisview

*

*@parammeasureSpec

*

AmeasureSpecpackedintoanint

*@returnTheheightoftheview,honoringconstraintsfrommeasureSpec

*/

privateintmeasureShort(intmeasureSpec){

intresult;

intspecMode=MeasureSpec.getMode(measureSpec);

intspecSize=MeasureSpec.getSize(measureSpec);

if(specMode==MeasureSpec.EXACTLY){

//Weweretoldhowbigtobe

result=specSize;

}else{

//Measuretheheight

result=(int)(2*mRadius+getPaddingTop()+getPaddingBottom()+1);

//RespectAT_MOSTvalueifthatwaswhatiscalledforbymeasureSpec

if(specMode==MeasureSpec.AT_MOST){

result=Math.min(result,specSize);

}

}

returnresult;

}

@Override

publicvoidonRestoreInstanceState(Parcelablestate){

SavedStatesavedState=(SavedState)state;

super.onRestoreInstanceState(savedState.getSuperState());

mCurrentPage=savedState.currentPage;

mSnapPage=savedState.currentPage;

requestLayout();

}

@Override

publicParcelableonSaveInstanceState()