Android首次打开APP启动页面定时进入滑动引导页面的实现

一、大部分APP应用首次打开的时候都会有一个定时进入引导页面的功能，滑动页面进入APP，这个效果的实现主要为三步骤。

1、先定义两个布局文件：activity_entry.xml、activity_main01.xml（此处为滑动的页面的布局，命名不规范）

2、对应布局文件的Activity为：EntryActiviy.class实现启动页面定时跳转效果，MainActivity01.class实现滑动引导页面，要重写ViewPagerAdapter.class类。

3、Activity主件必须mainfests.xml中配置，很多新手老忘了，要再mainfests.xml清单中配置的组件包括四大组件Activities, ContentProviders, Services, 和Intent Receivers,还能指定permissions和instrumentation。

接下来我们来看具体的实现代码，还有很多实现方法，作为菜鸟能实现功能，我已经感到很满足了，所以学友要是有其他号方法也欢迎互相分享！

二、布局文件相对比较简单，不再赘述，直接看代码吧

1.activity_entry.xml

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

    <ImageView
        android:id="@+id/entry"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:src="@drawable/img_entry"/>
  </LinearLayout>

2.activity_main01.xml,这里用ViewPager可以自带滑动功能，注意布局要用FramLayout,用后面加载的页面盖住之前加载的页面，在对应的Activity中记得用Inflate()动态将布局文件加载进去，否则没办法实现。

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

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

<RelativeLayout
 android:orientation="vertical"
 android:layout_width="wrap_content"
  android:layout_height="wrap_content" >

<LinearLayout
    android:id="@+id/dot"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_marginBottom="30dp"
    android:gravity="center_horizontal"
    android:orientation="horizontal"
    >

</LinearLayout>
<Button
    android:id="@+id/startButton"
    android:layout_width="100dp"
    android:layout_height="50dp"
    android:text="立即体验"
    android:layout_centerHorizontal="true"
    android:visibility="gone"
    android:layout_above="@id/dot"
    android:background="@drawable/button"
    android:layout_gravity="center_horizontal"/>
  </RelativeLayout>
</FrameLayout>

三、实现布局文件相应的Activity

1.EntryActivity 用handler机制设置让消息延迟5s发送

public class EntryActivity extends AppCompatActivity {

private ImageView entry;

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //获取当前窗口，并调用windowsManager来控制窗口
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    requestWindowFeature(Window.FEATURE_NO_TITLE);//去掉头部的标题
    setContentView(R.layout.activity_entry);
    //用handler的消息传递机制，让消息延迟5s发送，注意要调用SystemClock.uptimeMillis()系统时钟
    handler.sendEmptyMessageAtTime(0,  SystemClock.uptimeMillis()+5000);
    entry = (ImageView) findViewById(R.id.entry);
}

private Handler handler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        getHome();
        super.handleMessage(msg);
    }
};
           //设置跳转页面
    private void getHome() {
    Intent intent2 = new Intent();
    intent2.setClass(EntryActivity.this, MainAcitvity01.class);
    startActivity(intent2);
    finish();
}}

3、滑动页面对应的ainainctivity.class

   public class MainAcitvity01 extends AppCompatActivity implements     
   ViewPager.OnPageChangeListener{
   private ViewPager vP;
   private int []imageArray;

  private ViewGroup viewGroup;
  private List<View> viewsList;

  private ImageView iv_point;
  private ImageView [] iv_PointArray;

  private Button button;
  @Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main01);

    button = (Button)findViewById(R.id.startButton);
    button.setOnClickListener(new View.OnClickListener(){

        @Override//设置监听，当滑动结束后点击按钮跳转到App主页面
        public void onClick(View v) {
            startActivity(new Intent(MainAcitvity01.this,MainActivity.class));
            finish();
        }
    });
     //初始化要加载的页面，即滑动页面
    initViewPager();
    //初始化活动要加载的点，即滑动时的小圆点
    initPoint();
}

  private void initViewPager(){
    //加载第一张启动页面
    vP = (ViewPager)findViewById(R.id.viewpager_launcher);
    //滑动页面放到一个imageArray数组中
    imageArray = new int[]{R.drawable.welcom_01,R.drawable.welcom_02,R.drawable.welcom_03};
    viewsList = new ArrayList<>();
    LinearLayout.LayoutParams params= new LinearLayout.LayoutParams
            (LinearLayout.LayoutParams.MATCH_PARENT,
            LinearLayout.LayoutParams.MATCH_PARENT);
    //获取imageArray数组的长度，现实当前页面，当数组中还有页面时，继续添加到viewList中显示
    int len = imageArray.length;
    for (int i = 0;i<len;i++){
        ImageView IV = new ImageView(this);
        IV.setLayoutParams(params);
        IV.setBackgroundResource(imageArray[i]);
        viewsList.add(IV);
    }
  //实例化ViewPagerAapter
    vP.setAdapter(new ViewPagerAdapter(viewsList));
    //设置滑动监听
    vP.setOnPageChangeListener(this);
}

private  void  initPoint() {
    viewGroup = (ViewGroup)findViewById(R.id.dot);
    iv_PointArray = new ImageView[viewsList.size()];
    int size = viewsList.size();
    for(int i = 0; i <size;i++){
        iv_point = new ImageView(this);
        //实例化圆点，设置圆点的参数大小，位置
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(60,60);
        lp.leftMargin = 20;
        lp.rightMargin = 20;
        iv_point.setLayoutParams(lp);


        iv_PointArray[i] = iv_point;
        if(i == 0){
            iv_point.setBackgroundResource(R.drawable.dot);
              }else{
            iv_point.setBackgroundResource(R.drawable.black_dot);
        }
        viewGroup.addView(iv_PointArray[i]);
    }
}

@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

}

@Override//滑动页面具体实现方法
public void onPageSelected(int position) {
    int lenth = imageArray.length;
    for (int i = 0; i < lenth; i++) {
        iv_PointArray[i].setBackgroundResource(R.drawable.dot);
        if (position != i) {
            iv_PointArray[i].setBackgroundResource(R.drawable.black_dot);
        }
        if (position == lenth - 1) {
            button.setVisibility(View.VISIBLE);
        } else {
            button.setVisibility(View.GONE);
        }
    }
}

@Override
public void onPageScrollStateChanged(int state) {

}}

4、重写ViewPagerAdapter

public class ViewPagerAdapter extends PagerAdapter {

 public List<View> views;

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

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

@Override
public Object instantiateItem(ViewGroup container, int position) {
    View view = views.get(position);
    container.addView(view);
    return view;
}

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

@Override
public boolean isViewFromObject(View arg0, Object arg1) {
    return arg0 == arg1;
}

}

5、在mainfests清单中配置Activity

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

  <application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".EntryActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name=".MainAcitvity01"/>
    <activity android:name=".MainActivity"/>

</application>
</manifest>

四、具体实现的效果图为

image.png image.png
image.png

第一次写花了3h终于写完了，希望自己能早点进步！