Android 启动页 Splash 和 Viewpager

Splash ：
xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"

    >
    <ImageView
        android:scaleType="fitXY"
        android:background="@drawable/splash"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

activity:

public class SplashActivity extends BaseActivity {


    private static final long DELAY_TIME = 3000L;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splash);
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                startActivity(new Intent(SplashActivity.this,MainActivity.class));
                finish();
            }
        },DELAY_TIME);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
    }
}

ViewPager的加载：
首先我们要新建一个WelcomeActivity的页面来搭载viewpager 以及原点指示器：
布局选择当然是帧布局了
xml:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <android.support.v4.view.ViewPager
        android:id="@+id/vp_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </android.support.v4.view.ViewPager>
    <LinearLayout
        android:id="@+id/ll_indicator"
        android:layout_width="wrap_content"
        android:background="@android:color/transparent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal|bottom"
        android:layout_marginBottom="60dp"
        android:orientation="horizontal"
        >
    </LinearLayout>

</FrameLayout>

WelcomeActivity:

public class WelcomeActivity extends FragmentActivity{

    private static final String TAG = "WelcomeActivity";
    private ViewPager vp_main;
    private LinearLayout ll_indicator;
    private ViewPagerAdapter adapter;
    private List<Fragment> fragmentList = new ArrayList<Fragment>();
    private ImmersionBar mImmersionBar;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //判断是否是第一次登录
        if(SpUtils.getSp(this,"Login",false)){
            startActivity(new Intent(this,MainActivity.class));
            finish();
        }
        mImmersionBar = ImmersionBar.with(this);
        mImmersionBar.init();   //所有子类都将继承这些相同的属性
        setContentView(R.layout.activity_welcome);
        initView();
        initDicator();
    }


    //初始化芝士条
    private void initDicator() {
        int width = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,10f,getResources().getDisplayMetrics());
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(width,width);
        lp.setMargins(4,0,4,0);


        for(int i=0;i<fragmentList.size();i++){
            View view = new View(this);
            view.setId(i);
            view.setBackgroundResource( i==0?R.drawable.dot_press_shap:R.drawable.dot_normal_shap);
            view.setLayoutParams(lp);
            ll_indicator.addView(view,i);
        }
    }


    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mImmersionBar != null)
            mImmersionBar.destroy();  //必须调用该方法，防止内存泄漏，不调用该方法，如果界面bar发生改变，在不关闭app的情况下，退出此界面再进入将记忆最后一次bar改变的状态
    }


    private void initView() {
        vp_main = (ViewPager) findViewById(R.id.vp_main);
        ll_indicator = (LinearLayout) findViewById(R.id.ll_indicator);

        //创建fragment
        for(int i=0;i<3;i++){
            ContentFragment fragment = new ContentFragment();
            Bundle bundle = new Bundle();
            bundle.putInt("index",i);
            Log.e(TAG,""+i);
            fragment.setArguments(bundle);
            fragmentList.add(fragment);
        }
        adapter = new ViewPagerAdapter(getSupportFragmentManager(),fragmentList);
        vp_main.setAdapter(adapter);
        vp_main.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
                for(int i = 0;i<fragmentList.size();i++){
                    ll_indicator.getChildAt(i).setBackgroundResource(position == i?R.drawable.dot_press_shap:R.drawable.dot_normal_shap);
                }

            }

            @Override
            public void onPageSelected(int position) {


            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });


    }
}

Drawable.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval"
    >
    <solid android:color="@color/colorPrimary"></solid>
    <corners android:radius="10dp"></corners>


</shape>

中间的难点就是fragment的创建以及怎么能判断哪个fragment对应哪一个。
我们用到了这个
Bundle bundle = new Bundle();
bundle.putInt("index",i);
fragment.setArguments(bundle);
来传递信息；
在我们的ContFragment中：

public class ContentFragment extends Fragment  {

    private static final String TAG = "ContentFragment";
    private Button bt_open;
    private ImageView iv_content;
    private int[] BgImg = {R.drawable.splash,R.drawable.cotent,R.drawable.open};


    public ContentFragment(){

    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_content,null);
        iv_content = (ImageView) view.findViewById(R.id.iv_content);
        bt_open = (Button) view.findViewById(R.id.bt_open);

        int index = getArguments().getInt("index");
       // iv_content.setBackgroundResource(BgImg[index]);
        iv_content.setImageResource(BgImg[index]);
        Log.e(TAG,""+index);
        bt_open.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                getActivity().startActivity(new Intent(getActivity(),MainActivity.class));
                getActivity().finish();
                SpUtils.setSp(getActivity(),"Login",true);


            }
        });

        bt_open.setVisibility(index == 2 ? View.VISIBLE:View.GONE);


        return view;
    }
}

xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"

    >
    <ImageView
        android:id="@+id/iv_content"
        android:scaleType="fitXY"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </ImageView>

    <Button
        android:id="@+id/bt_open"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:gravity="center"
        android:textSize="22sp"
        android:text="进入体验"
        android:layout_marginBottom="10dp"
        />

在其中我遇到了fragment加载不出来图片加载出来全是白色
原因是ViewPagerAdapter写错了：
正确的：

public class ViewPagerAdapter extends FragmentPagerAdapter{

    private List<Fragment> mlist;

    public ViewPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    public ViewPagerAdapter(FragmentManager fm,List<Fragment> mlist) {
        super(fm);
        this.mlist = mlist;
    }

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

    @Override
    public Fragment getItem(int position) {
        return mlist.get(position);
    }


}

而我原先继承的是PagerAdapter导致多了这个方法

 @Override
    public boolean isViewFromObject(View view, Object object) {
        return false;
    }

只要改为FragmentAdapter并且删除这个方法就行

那我的BaseActivity是啥呢？

public class BaseActivity extends AppCompatActivity {

    private ImmersionBar mImmersionBar;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mImmersionBar = ImmersionBar.with(this);
        mImmersionBar.init();   //所有子类都将继承这些相同的属性

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mImmersionBar != null)
            mImmersionBar.destroy();  //必须调用该方法，防止内存泄漏，不调用该方法，如果界面bar发生改变，在不关闭app的情况下，退出此界面再进入将记忆最后一次bar改变的状态
    }
}

这是一个沉浸式框架 ，具体看
gitHub地址：https://github.com/gyf-dev/ImmersionBar