ViewPager设置启动页(仅供自己学习使用)

学习与此
启动页代码

public class SplashActivity extends AppCompatActivity {

    private final int SPLASH_DISPLAY_LENGHT = 2000; // 延迟2秒
    private SharedPreferences preferences;
    private SharedPreferences.Editor editor;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splash);
        //获得sharedpreferences的实体,第二个参数为模式
        preferences = getSharedPreferences("isFirstStart", Context.MODE_PRIVATE);
        new Handler().postDelayed(new Runnable() {

            @Override
            public void run() {
                if (preferences.getBoolean("firststart", true)) {
                    editor = preferences.edit();
                    // 将登录标志位设置为false，下次登录时不再显示引导页面
                    editor.putBoolean("firststart", false);
                    editor.commit();
                    Intent intent = new Intent();
                    intent.setClass(SplashActivity.this, WelcomeActivity.class);
                    SplashActivity.this.startActivity(intent);
                    SplashActivity.this.finish();
                } else {
                    Intent intent = new Intent();
                    intent.setClass(SplashActivity.this, LoginActivity.class);
                    SplashActivity.this.startActivity(intent);
                    SplashActivity.this.finish();
                }
            }
        }, SPLASH_DISPLAY_LENGHT);
    }
}

AndroidManifest中设置theme背景

        <activity android:name=".activity.SplashActivity"
            android:theme="@style/SplashTheme">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>

styles设置启动页背景

    <style name="AppBaseTheme" parent="Theme.AppCompat.Light.NoActionBar">
    </style>

    <style name="SplashTheme" parent="AppBaseTheme">
        <item name="android:windowIsTranslucent">false</item>
        <!-- 设置没有标题 -->
        <!--未能起效-->
        <item name="android:windowNoTitle">true</item>
        <!-- 设置背景 -->
        <item name="android:windowBackground">@drawable/splash_bg</item>
    </style>

WelcomeActivity代码

• 图片设置setImageResource图片不能铺满屏幕,采取setBackgroundResource方法
• dots[i] = (ImageView) ll_dot.getChildAt(i);//学到了通过这种方法得到线性布局子布局

public class WelcomeActivity extends AppCompatActivity  implements ViewPager.OnPageChangeListener,View.OnClickListener {

    private ViewPager vp;
    private ViewPagerAdapter vpAdapter;
    private List<View> views;
    private LinearLayout ll_dot;
    private Button btn_goLogin;
    // 引导图片资源
    private static final int[] pics = { R.drawable.guide1, R.drawable.guide2, R.drawable.guide3};

    // 底部小点图片
    private ImageView[] dots;

    // 记录当前选中位置
    private int currentIndex;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_welcome);
        initGui();
        initAction();
        initViewPager();
        // 初始化底部小圆点
        initDots();
    }

    private void initGui() {
        btn_goLogin = (Button) findViewById(R.id.btn_gologin);
        vp = (ViewPager) findViewById(R.id.viewpager);
        ll_dot = (LinearLayout) findViewById(R.id.ll_dot);
    }

    protected void initAction() {
        btn_goLogin.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_gologin:
                Intent intent = new Intent();
                intent.setClass(WelcomeActivity.this, LoginActivity.class);
                WelcomeActivity.this.startActivity(intent);
                finish();
                break;
            default:
                break;
        }
    }

    private void initViewPager() {
        views = new ArrayList<View>();
        // 为引导图片提供布局参数
     //   LinearLayout.LayoutParams mParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        // 初始化引导图片列表
        for (int i = 0; i < pics.length; i++) {
            ImageView iv = new ImageView(this);
            //iv.setLayoutParams(mParams);
          //  iv.setImageResource(pics[i]);这种方式不能图片铺满屏幕
           iv.setBackgroundResource(pics[i]);
            views.add(iv);
        }
        // 初始化Adapter
        vpAdapter = new ViewPagerAdapter(views);
        vp.setAdapter(vpAdapter);
        // 绑定回调
        vp.setOnPageChangeListener(this);
    }



    private void initDots() {
        dots = new ImageView[pics.length];
        // 循环取得小点图片
        for (int i = 0; i < pics.length; i++) {
            //View android.view.ViewGroup.getChildAt(int index)：
            //Returns the view at the specified position in the group.
            dots[i] = (ImageView) ll_dot.getChildAt(i);//以后通过这种方法得到线性布局子布局
            dots[i].setEnabled(false);// 都设为黑色
            dots[i].setTag(i);// 设置位置tag，方便取出与当前位置对应
            //View中的setTag(Onbect)表示给View添加一个格外的数据，以后可以用getTag()将这个数据取出来。
        }

        currentIndex = 0;
        dots[currentIndex].setEnabled(true);// 设置为红色，即选中状态
    }

    /**
     * 改变当前引导小点颜色ؿ
     */
    private void setCurDot(int positon) {
        if (positon < 0 || positon > pics.length - 1 || currentIndex == positon) {
            return;
        }
        System.out.println("positon="+positon);
        dots[positon].setEnabled(true);
        //此时的currentIndex指的是上一个圆点
        System.out.println("currentIndex="+currentIndex);
        dots[currentIndex].setEnabled(false);
        //现在的currentIndex指的是当前的小圆点
        currentIndex = positon;
    }

    // 当滑动状态改变时调用
    @Override
    public void onPageScrollStateChanged(int arg0) {
        // TODO Auto-generated method stub

    }

    // 当前页面被滑动时调用
    @Override
    public void onPageScrolled(int arg0, float arg1, int arg2) {
        // TODO Auto-generated method stub

    }

    // 当新的页面被选中时调用
    @Override
    public void onPageSelected(int arg0) {
        // 设置底部小点选中状态
        setCurDot(arg0);
        if (arg0 == 2) {
            btn_goLogin.setVisibility(View.VISIBLE);
        } else {
            btn_goLogin.setVisibility(View.GONE);
        }
    }
}

WelcomeActivity xml文件

<?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"
    android:orientation="vertical" >

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


    <LinearLayout
        android:id="@+id/ll_dot"
        android:orientation="horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="24.0dip"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true">

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:clickable="true"
            android:padding="15.0dip"
            android:src="@drawable/selector_dots" />

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:clickable="true"
            android:padding="15.0dip"
            android:src="@drawable/selector_dots" />

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:clickable="true"
            android:padding="15.0dip"
            android:src="@drawable/selector_dots" />


    </LinearLayout>
    <Button
        android:id="@+id/btn_gologin"
        android:background="@color/cornsilk"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="立即登陆"
        android:layout_above="@id/ll_dot"
        android:layout_centerHorizontal="true"
        android:visibility="gone"
        />

</RelativeLayout>

使用xml定义小圆点的选择背景

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

    <item android:drawable="@drawable/dot_true" android:state_enabled="true"/>
    <item android:drawable="@drawable/dot_false" android:state_enabled="false"/>
    <item android:drawable="@drawable/dot_false"/>

</selector>

dot_false即为未选择图片小圆点的颜色

<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <!--<corners android:radius="10dp" />-->
    <!--<stroke-->
        <!--android:width="1dip"-->
        <!--android:color="@android:color/darker_gray" />-->
    <!-- 大小 -->
    <size
        android:width="10dp"
        android:height="10dp" /><!-- 宽度和高度 -->
    <!-- 线的宽度，颜色灰色 -->
    <stroke android:width="0dp" android:color="#D5D5D5"></stroke>
    <!-- 填充 -->
    <solid android:color="#33000000" /><!-- 填充的颜色 -->

    <!-- 描边 -->
    <!--<stroke-->
        <!--android:color="@android:color/black"-->
        <!--android:dashWidth="0dp" />-->
</shape> 

dot_true即为选择图片小圆点的颜色

<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <!--<corners android:radius="10dp" />-->
    <!--<stroke-->
        <!--android:width="1dip"-->
        <!--android:color="@android:color/darker_gray" />-->
    <!-- 大小 -->
    <size
        android:width="10dp"
        android:height="10dp" /><!-- 宽度和高度 -->
    <!-- 线的宽度，颜色灰色 -->
    <stroke android:width="0dp" android:color="#D5D5D5"></stroke>
    <!-- 填充 -->
    <solid android:color="#FFFFFF" /><!-- 填充的颜色 -->

    <!-- 描边 -->
    <!--<stroke-->
        <!--android:color="@android:color/black"-->
        <!--android:dashWidth="0dp" />-->
</shape> 

适配器

public class ViewPagerAdapter extends PagerAdapter {
    private List<View> mViewList ;

    public ViewPagerAdapter(List<View> mViewList ) {
        this.mViewList = mViewList;
    }

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

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

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        container.addView(mViewList.get(position));
        return mViewList.get(position);
    }

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