Android中的ViewPager（一）

<android.support.v4.view.ViewPager
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</android.support.v4.view.ViewPager>

viewPager.setAdapter(new ColorPagerAdapter(new ColorData()))

protected final IColorData colorData;

public ColorPagerAdapter(IColorData colorData) {
this.colorData = colorData;
}

@Override
public int getCount() {
return colorData.getCount();
}

public Object instantiateItem(ViewGroup container, int position) {
View view = LayoutInflater.from(container.getContext()).inflate(R.layout.page_color, container, false);

container.addView(view);

setupPage(view, position);

return view;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}

@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
//设置页面
private void setupPage(View view, int index) {
view.setBackgroundColor(colorData.getColorValue(index));
TextView tvColorName = (TextView) view.findViewById(R.id.color_name);
tvColorName.setText(colorData.getColorName(index));
}

viewPager.setOffscreenPageLimit(2);

@Override
public float getPageWidth(int position) {
return 0.5f + 0.1f * position;
}