简单实现 一条线 跟随 viewpager 滚动.zip项目安卓应用源码下载

package com.androidapp.viewpager; import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.graphics.Matrix; 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.util.DisplayMetrics; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.View.OnClickListener; import android.view.animation.Animation; import android.view.animation.TranslateAnimation; import android.widget.ImageView; import android.widget.TextView; import android.widget.Toast; public class TestViewPagerActivity extends Activity { ViewPager viewPager;// ViewPager对象 ImageView img_bottom_line;// 跟随图标 TextView text_one;// 标题1 TextView text_two;// 标题2 TextView text_three;// 标题3 int currIndex = 0;// 当前页卡编号 int bmpW;// 图片宽度 int offset;// 动画图片偏移量 View view1; View view2; View view3; List<View> views; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); initImageView(); initTextView(); initViewPager(); } public void initTextView() { text_one = (TextView) findViewById(R.id.text_one); text_two = (TextView) findViewById(R.id.text_two); text_three = (TextView) findViewById(R.id.text_three); text_one.setOnClickListener(new MyOnClick(0)); text_two.setOnClickListener(new MyOnClick(1)); text_three.setOnClickListener(new MyOnClick(2)); } public void initImageView() { img_bottom_line = (ImageView) findViewById(R.id.img_bottom_line); bmpW = img_bottom_line.getLayoutParams().width; // BitmapFactory.decodeResource(getResources(), id); DisplayMetrics dm = new DisplayMetrics(); getWindowManager().getDefaultDisplay().getMetrics(dm); int screenW = dm.widthPixels; System.out.println("------------" + screenW); offset = (screenW / 3 - bmpW) / 2; Matrix matrix = new Matrix(); matrix.postTranslate(offset, 0); img_bottom_line.setImageMatrix(matrix);// 设置动画初始位置 } public void initViewPager() { viewPager = (ViewPager) findViewById(R.id.viewPager); views = new ArrayList<View>(); LayoutInflater inflater = getLayoutInflater(); view1 = inflater.inflate(R.layout.one, null); view2 = inflater.inflate(R.layout.two, null); view3 = inflater.inflate(R.layout.three, null); views.add(view1); views.add(view2); views.add(view3); viewPager.setAdapter(new MyViewPageAdapter(views)); viewPager.setCurrentItem(0); viewPager.setOnPageChangeListener(new MyOnPageChangeListener()); } class MyViewPageAdapter extends PagerAdapter { private List<View> listViews; MyViewPageAdapter(List<View> listViews) { this.listViews = listViews; } @Override public void destroyItem(ViewGroup container, int position, Object object) { container.removeView(listViews.get(position)); } @Override public Object instantiateItem(ViewGroup container, int position) { container.addView(listViews.get(position), 0); return listViews.get(position); } @Override public int getCount() { return listViews.size(); } @Override public boolean isViewFromObject(View arg0, Object arg1) { return arg0 == arg1; } } class MyOnPageChangeListener implements OnPageChangeListener { int one = offset * 2 + bmpW;// 页卡1-->页卡2 偏移量 int two = offset * 2;// 页卡2-->页卡3 偏移量 @Override public void onPageScrollStateChanged(int arg0) { } @Override public void onPageScrolled(int arg0, float arg1, int arg2) { } /** * 页卡切换监听 */ @Override public void onPageSelected(int arg0) { Animation animation = new TranslateAnimation(one * currIndex, one * arg0, 0, 0); currIndex = arg0; animation.setFillAfter(true);// True:图片停在动画结束位置 animation.setDuration(300); img_bottom_line.startAnimation(animation); Toast.makeText(TestViewPagerActivity.this, "您选择了" + viewPager.getCurrentItem() + "页卡", Toast.LENGTH_SHORT).show(); } } /** * 表头点击事件 * * @author GM * */ class MyOnClick implements OnClickListener { int index = 0; MyOnClick(int i) { this.index = i; } @Override public void onClick(View v) { viewPager.setCurrentItem(index); } } }