一、主界面

package com.example.t;

import android.app.Activity;

import android.os.Bundle;

import android.support.v4.view.ViewPager;

import android.support.v4.view.ViewPager.OnPageChangeListener;

public class MainActivity extends Activity implements OnPageChangeListener {

private CirclePageIndicator indicator;

private ViewPager viewpager;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

initview();

}

private void initview() {

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

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

indicator.setStrokeWidth(0);

indicator.setPageCircleColor(0xFFFFFFFF);

viewpager.setAdapter(new Myadapter(this));

indicator.setViewPager(viewpager);

indicator.setOnPageChangeListener(this);

}

@Override

public void onPageScrollStateChanged(int arg0) {

}

@Override

public void onPageScrolled(int arg0, float arg1, int arg2) {

}

@Override

public void onPageSelected(int arg0) {

}

}

二、广告适配器

package com.example.t;

import android.content.Context;

import android.support.v4.view.PagerAdapter;

import android.support.v4.view.ViewPager.LayoutParams;

import android.view.View;

import android.view.ViewGroup;

import android.widget.ImageView;

import android.widget.ImageView.ScaleType;

public class Myadapter extends PagerAdapter {

private Context context;

private int[] p_w_picpaths;

public Myadapter(Context context) {

this.context = context;

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

}

@Override

public int getCount() {

return p_w_picpaths.length;

}

// 判断View和Object是否为同一个View

@Override

public boolean isViewFromObject(View view, Object object) {

return view == object;

}

// 控制当某个View不需要的时候的回收处理

@Override

public void destroyItem(ViewGroup container, int position, Object object) {

container.removeView((View) object);

}

// 实例化Item：即 得到每个View

@Override

public Object instantiateItem(ViewGroup container, int position) {

ImageView iv = new ImageView(context);

iv.setScaleType(ScaleType.CENTER_CROP);

android.view.ViewGroup.LayoutParams params = new android.view.ViewGroup.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);

iv.setLayoutParams(params);

iv.setImageResource(p_w_picpaths[position]);

container.addView(iv);

return iv;

}

}

三、小圆点指示器

package com.example.t;

import static android.graphics.Paint.ANTI_ALIAS_FLAG;

import static android.widget.LinearLayout.HORIZONTAL;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Paint;

import android.graphics.Paint.Style;

import android.os.Parcel;

import android.os.Parcelable;

import android.support.v4.view.MotionEventCompat;

import android.support.v4.view.ViewConfigurationCompat;

import android.support.v4.view.ViewPager;

import android.support.v4.view.ViewPager.OnPageChangeListener;

import android.util.AttributeSet;

import android.view.MotionEvent;

import android.view.View;

import android.view.ViewConfiguration;

/**

* @describe view pager 的小圆点指示器

*/

public class CirclePageIndicator extends View implements OnPageChangeListener {

private static final int INVALID_POINTER = -1;

private float mRadius;

private final Paint mPaintPageFill = new Paint(ANTI_ALIAS_FLAG);

private final Paint mPaintStroke = new Paint(ANTI_ALIAS_FLAG);

private final Paint mPaintFill = new Paint(ANTI_ALIAS_FLAG);

private ViewPager mViewPager;

private ViewPager.OnPageChangeListener mListener;

private int mCurrentPage;

private int mSnapPage;

private float mPageOffset;

private int mScrollState;

private int mOrientation;

private boolean mCentered;

private boolean mSnap;

private int mTouchSlop;

private float mLastMotionX = -1;

private int mActivePointerId = INVALID_POINTER;

private boolean mIsDragging;

private Context context;

public CirclePageIndicator(Context context) {

super(context);

this.context = context;

init(context);

}

public CirclePageIndicator(Context context, AttributeSet attrs) {

super(context, attrs);

init(context);

}

private void init(Context context) {

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;

final ViewConfiguration configuration = ViewConfiguration.get(context);

mTouchSlop = ViewConfigurationCompat.getScaledPagingTouchSlop(configuration);

}

public void setRadius(int dpValue) {

float scale=context.getResources().getDisplayMetrics().density;

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

invalidate();

}

public float fraction;

private float parseRadiusIfNeed(float pageFillRadius) {

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

}

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

if (mViewPager == null) {

return;

}

final int count = mViewPager.getAdapter().getCount();

if (count == 0) {

return;

}

if (mCurrentPage >= count) {

setCurrentItem(count - 1);

return;

}

int longSize;

int longPaddingBefore;

int longPaddingAfter;

int shortPaddingBefore;

if (mOrientation == HORIZONTAL) {

longSize = getWidth();

longPaddingBefore = getPaddingLeft();

longPaddingAfter = getPaddingRight();

shortPaddingBefore = getPaddingTop();

} else {

longSize = getHeight();

longPaddingBefore = getPaddingTop();

longPaddingAfter = getPaddingBottom();

shortPaddingBefore = getPaddingLeft();

}

final float threeRadius = mRadius * 5;

final float shortOffset = shortPaddingBefore + mRadius;

float longOffset = longPaddingBefore + mRadius;

if (mCentered) {

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

}

float dX;

float dY;

float pageFillRadius = mRadius;

if (mPaintStroke.getStrokeWidth() > 0) {

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

}

// Draw stroked circles

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

float drawLong = longOffset + (iLoop * threeRadius);

if (mOrientation == HORIZONTAL) {

dX = drawLong;

dY = shortOffset;

} else {

dX = shortOffset;

dY = drawLong;

}

// Only paint fill if not completely transparent

if (mPaintPageFill.getAlpha() > 0) {

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

}

// Only paint stroke if a stroke width was non-zero

if (pageFillRadius != mRadius) {

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

}

}

// Draw the filled circle according to the current scroll

float cx = (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);

}

public boolean onTouchEvent(android.view.MotionEvent ev) {

if (super.onTouchEvent(ev)) {

return true;

}

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

return false;

}

final int action = ev.getAction() & MotionEventCompat.ACTION_MASK;

switch (action) {

case MotionEvent.ACTION_DOWN:

mActivePointerId = MotionEventCompat.getPointerId(ev, 0);

mLastMotionX = ev.getX();

break;

case MotionEvent.ACTION_MOVE: {

final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);

final float x = MotionEventCompat.getX(ev, activePointerIndex);

final float deltaX = x - mLastMotionX;

if (!mIsDragging) {

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

mIsDragging = true;

}

}

if (mIsDragging) {

mLastMotionX = x;

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

mViewPager.fakeDragBy(deltaX);

}

}

break;

}

case MotionEvent.ACTION_CANCEL:

case MotionEvent.ACTION_UP:

if (!mIsDragging) {

final int count = mViewPager.getAdapter().getCount();

final int width = getWidth();

final float halfWidth = width / 2f;

final float sixthWidth = width / 6f;

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

if (action != MotionEvent.ACTION_CANCEL) {

mViewPager.setCurrentItem(mCurrentPage - 1);

}

return true;

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

if (action != MotionEvent.ACTION_CANCEL) {

mViewPager.setCurrentItem(mCurrentPage + 1);

}

return true;

}

}

mIsDragging = false;

mActivePointerId = INVALID_POINTER;

if (mViewPager.isFakeDragging())

mViewPager.endFakeDrag();

break;

case MotionEventCompat.ACTION_POINTER_DOWN: {

final int index = MotionEventCompat.getActionIndex(ev);

mLastMotionX = MotionEventCompat.getX(ev, index);

mActivePointerId = MotionEventCompat.getPointerId(ev, index);

break;

}

case MotionEventCompat.ACTION_POINTER_UP:

final int pointerIndex = MotionEventCompat.getActionIndex(ev);

final int pointerId = MotionEventCompat.getPointerId(ev, pointerIndex);

if (pointerId == mActivePointerId) {

final int newPointerIndex = pointerIndex == 0 ? 1 : 0;

mActivePointerId = MotionEventCompat.getPointerId(ev, newPointerIndex);

}

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

break;

}

return true;

}

public void setViewPager(ViewPager view) {

if (mViewPager == view) {

return;

}

if (mViewPager != null) {

mViewPager.setOnPageChangeListener(null);

}

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

throw new IllegalStateException("ViewPager does not have adapter instance.");

}

mViewPager = view;

mViewPager.setOnPageChangeListener(this);

invalidate();

}

public void setViewPager(ViewPager view, int initialPosition) {

setViewPager(view);

setCurrentItem(initialPosition);

}

public void setCurrentItem(int item) {

if (mViewPager == null) {

throw new IllegalStateException("ViewPager has not been bound.");

}

mViewPager.setCurrentItem(item);

mCurrentPage = item;

invalidate();

}

public void notifyDataSetChanged() {

invalidate();

}

@Override

public void onPageScrollStateChanged(int state) {

mScrollState = state;

if (mListener != null) {

mListener.onPageScrollStateChanged(state);

}

}

@Override

public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

mCurrentPage = position;

mPageOffset = positionOffset;

invalidate();

if (mListener != null) {

mListener.onPageScrolled(position, positionOffset, positionOffsetPixels);

}

}

@Override

public void onPageSelected(int position) {

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

mCurrentPage = position;

mSnapPage = position;

invalidate();

}

if (mListener != null) {

mListener.onPageSelected(position);

}

}

public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {

mListener = listener;

}

/**

* 设置圆边框的颜色

*/

public void setStrokeColor(int color) {

try {

mPaintStroke.setColor(color);

} catch (Exception e) {

mPaintStroke.setColor(0xFFFF6600);

e.printStackTrace();

}

}

/**

* 设置中心圆的颜色

*

* @param color

*/

public void setCircleColor(int color) {

try {

mPaintFill.setColor(color);

} catch (Exception e) {

mPaintFill.setColor(0xFFFF6600);

e.printStackTrace();

}

}

public void setPageCircleColor(int color) {

try {

mPaintPageFill.setColor(color);

} catch (Exception e) {

mPaintPageFill.setColor(0x00000000);

e.printStackTrace();

}

}

public void setStrokeWidth(float width) {

mPaintStroke.setStrokeWidth(width);

}

/*

* (non-Javadoc)

*

* @see android.view.View#onMeasure(int, int)

*/

@Override

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

if (mOrientation == HORIZONTAL) {

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

} else {

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

}

}

/**

* Determines the width of this view

*

* @param measureSpec

*            A measureSpec packed into an int

* @return The width of the view, honoring constraints from measureSpec

*/

private int measureLong(int measureSpec) {

int result;

int specMode = MeasureSpec.getMode(measureSpec);

int specSize = MeasureSpec.getSize(measureSpec);

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

// We were told how big to be

result = specSize;

} else {

// Calculate the width according the views count

final int count = mViewPager.getAdapter().getCount();

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

// Respect AT_MOST value if that was what is called for by measureSpec

if (specMode == MeasureSpec.AT_MOST) {

result = Math.min(result, specSize);

}

}

return result;

}

/**

* Determines the height of this view

*

* @param measureSpec

*            A measureSpec packed into an int

* @return The height of the view, honoring constraints from measureSpec

*/

private int measureShort(int measureSpec) {

int result;

int specMode = MeasureSpec.getMode(measureSpec);

int specSize = MeasureSpec.getSize(measureSpec);

if (specMode == MeasureSpec.EXACTLY) {

// We were told how big to be

result = specSize;

} else {

// Measure the height

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

// Respect AT_MOST value if that was what is called for by measureSpec

if (specMode == MeasureSpec.AT_MOST) {

result = Math.min(result, specSize);

}

}

return result;

}

@Override

public void onRestoreInstanceState(Parcelable state) {

SavedState savedState = (SavedState) state;

super.onRestoreInstanceState(savedState.getSuperState());

mCurrentPage = savedState.currentPage;

mSnapPage = savedState.currentPage;

requestLayout();

}

@Override

public Parcelable onSaveInstanceState() {

Parcelable superState = super.onSaveInstanceState();

SavedState savedState = new SavedState(superState);

savedState.currentPage = mCurrentPage;

return savedState;

}

static class SavedState extends BaseSavedState {

int currentPage;

public SavedState(Parcelable superState) {

super(superState);

}

private SavedState(Parcel in) {

super(in);

currentPage = in.readInt();

}

@Override

public void writeToParcel(Parcel dest, int flags) {

super.writeToParcel(dest, flags);

dest.writeInt(currentPage);

}

public static final Parcelable.Creator CREATOR = new Parcelable.Creator() {

@Override

public SavedState createFromParcel(Parcel in) {

return new SavedState(in);

}

@Override

public SavedState[] newArray(int size) {

return new SavedState[size];

}

};

}

}

四、布局xml

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:background="#55000000"

android:orientation="vertical" >

android:id="@+id/indicator"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:padding="5dp" />

android:id="@+id/viewpager"

android:layout_width="match_parent"

android:layout_height="wrap_content" >

五、用到的资源

1dp

4dp