Android开发之开发者头条(一)启动页实现

<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"
android:background="#FCF2E4">
<android.support.v4.view.ViewPager
android:id="@+id/viewpager_launcher"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<LinearLayout
android:id="@+id/viewGroup"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_marginBottom="30dp"
android:gravity="center_horizontal"
android:orientation="horizontal"/>
</RelativeLayout>
</RelativeLayout>

/**
* 第一次启动页面
* 
* @author Ansen
* @create time 2016-04-15
*/
@SuppressLint("ResourceAsColor")
public class LauncherActivity extends FragmentActivity implements ILauncherView {
private ViewPager viewpagerLauncher;
private LauncherPagerAdapter adapter;
private ImageView[] tips;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_luancher);
if(!isFirst()){
gotoMain();
}
viewpagerLauncher = (ViewPager) findViewById(R.id.viewpager_launcher);
adapter = new LauncherPagerAdapter(this, this);
viewpagerLauncher.setOffscreenPageLimit(2);
viewpagerLauncher.setCurrentItem(0);
viewpagerLauncher.setOnPageChangeListener(changeListener);
viewpagerLauncher.setAdapter(adapter);
viewpagerLauncher.setOnPageChangeListener(changeListener);
ViewGroup group = (ViewGroup) findViewById(R.id.viewGroup);// 初始化底部显示控件
tips = new ImageView[4];
for (int i = 0; i < tips.length; i++) {
ImageView imageView = new ImageView(this);
if (i == 0) {
imageView.setBackgroundResource(R.drawable.page_indicator_focused);
} else {
imageView.setBackgroundResource(R.drawable.page_indicator_unfocused);
}
tips[i] = imageView;
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(new ViewGroup.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));
layoutParams.leftMargin = 10;// 设置点点点view的左边距
layoutParams.rightMargin = 10;// 设置点点点view的右边距
group.addView(imageView, layoutParams);
}
}
private OnPageChangeListener changeListener = new OnPageChangeListener() {
@Override
public void onPageScrollStateChanged(int arg0) {}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {}
@Override
public void onPageSelected(int index) {
setImageBackground(index);// 改变点点点的切换效果
TextView tvStartHeadlines = (TextView) adapter.getViews().get(index).findViewById(R.id.tv_start_headlines);
if (index == tips.length - 1) {// 最后一个
tvStartHeadlines.setVisibility(View.VISIBLE);
} else {
tvStartHeadlines.setVisibility(View.INVISIBLE);
}
}
};
/**
* 改变点点点的切换效果
* @param selectItems
*/
private void setImageBackground(int selectItems) {
for (int i = 0; i < tips.length; i++) {
if (i == selectItems) {
tips[i].setBackgroundResource(R.drawable.page_indicator_focused);
} else {
tips[i].setBackgroundResource(R.drawable.page_indicator_unfocused);
}
}
}
@Override
public void gotoMain() {
Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);
finish();
}
private boolean isFirst() {
SharedPreferences setting = getSharedPreferences("headlines", 0);
Boolean user_first = setting.getBoolean("FIRST", true);
if (user_first) {// 第一次
setting.edit().putBoolean("FIRST", false).commit();
return true;
} else {
return false;
}
}
}

/**
* ViewPager适配器
* @author ansen
* @create time 2016-04-15
*/
public class LauncherPagerAdapter extends PagerAdapter implements OnClickListener{
private ILauncherView launcherView;
private List<View> views;
//每页显示的图片
private int[] images=new int[]{R.drawable.tutorial_1,R.drawable.tutorial_2,R.drawable.tutorial_3,R.drawable.tutorial_4};
public LauncherPagerAdapter(Context context,ILauncherView launcherView){
views=new ArrayList<View>();
this.launcherView=launcherView;
//初始化每页显示的View
for(int i=0;i<images.length;i++){
View item=LayoutInflater.from(context).inflate(R.layout.activity_luancher_pager_item, null);
ImageView imageview=(ImageView) item.findViewById(R.id.imageview);
imageview.setImageResource(images[i]);
item.findViewById(R.id.tv_start_headlines).setOnClickListener(this);
views.add(item);
}
}
public List<View> getViews() {
return views;
}
@Override
public int getCount() {
return views == null ? 0 : views.size();
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0==arg1;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object){
((ViewPager) container).removeView(views.get(position));
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
((ViewPager) container).addView(views.get(position), 0);
return views.get(position);
}
@Override
public void onClick(View v) {
launcherView.gotoMain();
}
}