标签：banner广告及view pager 的小圆点指示器
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[] images;
public Myadapter(Context context) {
this.context = context;
images = new int[] {R.drawable.default_img_mid, R.drawable.default_img_mid, R.drawable.default_img_mid };
}
@Override
public int getCount() {
return images.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(images[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<SavedState> CREATOR = new Parcelable.Creator<SavedState>() {
@Override
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
@Override
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}
}
四、布局xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#55000000"
android:orientation="vertical" >
<com.example.t.CirclePageIndicator
android:id="@+id/indicator"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="5dp" />
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</android.support.v4.view.ViewPager>
</LinearLayout>
五、用到的资源
<dimen name="indicator_stroke_width">1dp</dimen>
<dimen name="indicator_radius">4dp</dimen>
标签：banner广告及view pager 的小圆点指示器
原文地址：http://9437752.blog.51cto.com/9427752/1580984
