Android实现实时滑动ViewPager的2种方式

<RelativeLayout 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"  tools:context="com.example.welcome.MainActivity" >   <android.support.v4.view.ViewPager  android:id="@+id/mViewPager"  android:layout_width="fill_parent"  android:layout_height="fill_parent" />   <FrameLayout  android:layout_width="fill_parent"  android:layout_height="wrap_content"  android:layout_alignParentTop="true"  android:layout_centerHorizontal="true"  android:layout_marginTop="30dp" >   <com.example.welcome.PagerCursor   android:id="@+id/pagerCursor"   android:layout_width="fill_parent"   android:layout_height="5dp" />  </FrameLayout>   <FrameLayout  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_alignParentBottom="true"  android:layout_centerHorizontal="true"  android:layout_marginBottom="30dp" >   <com.example.welcome.CustomeDotGroup   android:id="@+id/ll_point_group"   android:layout_width="fill_parent"   android:layout_height="10dp"   android:orientation="horizontal" >  </com.example.welcome.CustomeDotGroup>   <View   android:id="@+id/red_point"   android:layout_width="10dp"   android:layout_height="10dp"   android:background="@drawable/point_red" />  </FrameLayout>  </RelativeLayout> 

package com.example.welcome;  import java.util.ArrayList;  import android.app.Activity; import android.os.Bundle; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.support.v4.view.ViewPager.OnPageChangeListener; import android.view.View; import android.view.ViewGroup; import android.view.animation.TranslateAnimation; import android.widget.ImageView;  public class MainActivity extends Activity {  private ViewPager mViewPager;   MyAdapter mAdapter;  private ArrayList<ImageView> imageViewList;  View red_point;  private int lastDis;  PagerCursor pagerCursor;  @SuppressWarnings("deprecation")  @Override  protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  pagerCursor = (PagerCursor) findViewById(R.id.pagerCursor);  red_point = findViewById(R.id.red_point);  imageViewList = new ArrayList<ImageView>();  int[] imagesInt = {R.drawable.p1,R.drawable.p2,R.drawable.p3};  for (int i = 0; i < imagesInt.length; i++) {   ImageView imageView = new ImageView(MainActivity.this);   imageView.setBackgroundResource(imagesInt[i]);   imageViewList.add(imageView);    }  mViewPager = (ViewPager) findViewById(R.id.mViewPager);    mAdapter = new MyAdapter();    mViewPager.setAdapter(mAdapter);    mViewPager.setOnPageChangeListener(new OnPageChangeListener() {     private boolean isDragging;      @Override   public void onPageSelected(int arg0) {      }     @Override   public void onPageScrolled(int position, float screenOffSet, int arg2) {   TranslateAnimation animation = null;   if (isDragging) {       int dp2px = PhoneUtils.dp2px(MainActivity.this, 20f);    int offSet = (int) (position*dp2px + dp2px*screenOffSet);       animation = new TranslateAnimation(lastDis, offSet, 0f, 0f);    animation.setDuration(200);    animation.setFillAfter(true);    red_point.startAnimation(animation);       lastDis = offSet;            }   float[] screenSize = MeasureUtil.getScreenSize(MainActivity.this);   float itemWidth = screenSize[0]/3;      pagerCursor.SetOffSet(position,screenOffSet,itemWidth);      }     @Override   public void onPageScrollStateChanged(int arg0) {   switch (arg0) {   case ViewPager.SCROLL_STATE_DRAGGING://滑动    isDragging = true;    break;   case ViewPager.SCROLL_STATE_IDLE://空闲    isDragging = false;    break;    default:    break;   }   }  });  }    class MyAdapter extends PagerAdapter{   @Override  public int getCount() {   return imageViewList.size();  }   @Override  public boolean isViewFromObject(View arg0, Object arg1) {   return arg0 == arg1;  }    @Override  public void destroyItem(ViewGroup container, int position, Object object) {   container.removeView(imageViewList.get(position));  }    @Override  public Object instantiateItem(ViewGroup container, int position) {   container.addView(imageViewList.get(position));   return imageViewList.get(position);  }    } } 

package com.example.welcome; import android.content.Context; import android.util.AttributeSet; import android.view.View; import android.widget.ImageView; import android.widget.LinearLayout;  public class CustomeDotGroup extends LinearLayout {   private Context context;  public CustomeDotGroup(Context context, AttributeSet attrs, int defStyle) {  super(context, attrs, defStyle);  this.context = context;  initRes();  }   public CustomeDotGroup(Context context, AttributeSet attrs) {  this(context, attrs, 0);  }   public CustomeDotGroup(Context context) {  this(context, null);  }     private void initRes() {  int dotWidthOrHeight = PhoneUtils.dp2px(context, 10);    for (int i = 0; i < 3; i++) {   ImageView dotImageView = new ImageView(context);   dotImageView.setBackgroundResource(R.drawable.point_normal);     LayoutParams dotImageViewParams = new LayoutParams(dotWidthOrHeight, dotWidthOrHeight);   if (i != 0) {   dotImageViewParams.leftMargin = dotWidthOrHeight;   }   dotImageView.setLayoutParams(dotImageViewParams);   this.addView(dotImageView);  }    }  }

package com.example.welcome;  import android.app.Activity; import android.content.Context; import android.graphics.Canvas; import android.graphics.Paint; import android.util.AttributeSet; import android.util.Log; import android.view.View;  public class PagerCursor extends View {  Context context;  private Paint mPaint;  private int screenWidth;  private int desRight;  private float itemWidth;   public PagerCursor(Context context, AttributeSet attrs, int defStyle) {  super(context, attrs, defStyle);  // TODO Auto-generated constructor stub  }   public PagerCursor(Context context, AttributeSet attrs) {  super(context, attrs);  this.context = context;  initRes();  // TODO Auto-generated constructor stub  }   public PagerCursor(Context context) {  super(context);  // TODO Auto-generated constructor stub  }   private void initRes() {  float[] screenSize = MeasureUtil.getScreenSize((Activity) context);  screenWidth = (int) screenSize[0];  Log.d("TAG", ",screenWidth" + screenWidth);   mPaint = new Paint();  mPaint.setColor(getResources().getColor(R.color.contentPressColor));  mPaint.setStyle(Paint.Style.FILL);  mPaint.setAntiAlias(true);  }   public void SetOffSet(int position, float screenOffSet, float itemWidth) {  int offSet = (int) (position * itemWidth + itemWidth * screenOffSet);  this.itemWidth = itemWidth;  desRight = offSet;  Log.d("TAG", "screenOffSet:" + screenOffSet + ",position" + position   + ",desRigh-->t" + desRight + ",itemWidth" + itemWidth);   invalidate();  }   @Override  protected void onDraw(Canvas canvas) {  super.onDraw(canvas);  Log.d("TAG", "onDraw,desRigh-->t" + desRight + ",itemWidth" + itemWidth);  canvas.drawRect(desRight, 0f, desRight + itemWidth,   PhoneUtils.dp2px(context, 5), mPaint);  } } 

package com.example.welcome;  import android.app.Activity; import android.util.DisplayMetrics;  /**  * 测绘工具�?  */ public final class MeasureUtil {  /**  * 获取屏幕尺寸  *  * @param activity  *  Activity  * @return 屏幕尺寸像素值，下标�?的�?为宽，下标为1的�?为高  */  public static float[] getScreenSize(Activity activity) {  DisplayMetrics metrics = new DisplayMetrics();  activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);  return new float[] { metrics.widthPixels, metrics.heightPixels };  } } 

package com.example.welcome;  import android.content.Context;  public class PhoneUtils {   public static int dp2px(Context context,float dpValue){  float scale = context.getResources().getDisplayMetrics().density;  return (int)(dpValue * scale +0.5f);  } }