为什么我这个 ViewPager 程序发布到手机就闪退

谁学逆向工程 2016-10-11 04:33:50

视频教程是苹果系统和eclipse。我是Windows和Android studio



<!-- view1.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">



    <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="第一个界面"/>

</LinearLayout>



<!-- view2.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">



    <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="第二个界面"/>

</LinearLayout>



<!-- view3.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">



    <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="第三个界面"/>

</LinearLayout>



<!-- view4.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">



    <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="第四个界面"/>

</LinearLayout>



//MyPagerAdapter.java

package com.example.administrator.viewpager;



import android.support.v4.view.PagerAdapter;

import android.view.View;

import android.view.ViewGroup;



import java.util.List;



/**

 * Created by Administrator on 2016/10/11.

 */

public class MyPagerAdapter extends PagerAdapter

{

    List<View> viewList;

    public  MyPagerAdapter(List<View> viewListv)

    {

        this.viewList = viewList;

    }

    //返回的是页卡的数量

    public int getCount()

    {

        return viewList.size();

    }



    //view是否来自于对象

    public boolean isViewFromObject(View view, Object object)

    {

        return view==object;

    }



    //实例化一个页卡

    public Object instantiateItem(ViewGroup container, int position)

    {

        container.addView(viewList.get(position));

        return viewList.get(position);

    }



    //销毁一个页卡

    public void destroyItem(ViewGroup container, int position, Object object)

    {

        container.removeView(viewList.get(position));

    }

}



//MainActivity.java

package com.example.administrator.viewpager;



import android.app.Activity;

import android.support.v4.view.ViewPager;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.view.ViewParent;



import java.util.ArrayList;

import java.util.List;



public class MainActivity extends Activity {



    List<View> viewList;

    ViewPager pager;

    protected void onCreate(Bundle savedInstanceState)

    {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        viewList = new ArrayList<View>();

        //通过View对象去作为ViewPager的数据源

        View view1 = View.inflate(this, R.layout.view1, null);

        View view2 = View.inflate(this, R.layout.view2, null);

        View view3 = View.inflate(this, R.layout.view3, null);

        View view4 = View.inflate(this, R.layout.view4, null);

        viewList.add(view1);

        viewList.add(view2);

        viewList.add(view3);

        viewList.add(view4);



        //初始化ViwPager

        pager = (ViewPager) findViewById(R.id.pager);



        //创建PagerAdapter的适配器

        MyPagerAdapter adapter = new MyPagerAdapter(viewList);



        //ViewPager加载适配器

        pager.setAdapter(adapter);

    }

}



<! activity_main.xml -->

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout 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:orientation="vertical">



    <android.support.v4.view.ViewPager

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_gravity="center"

        android:id="@+id/pager">

    </android.support.v4.view.ViewPager>



</LinearLayout>