Question

我在android中将此应用程序设置为“ Edversity”，并且遇到了无法自行解决的错误。布局很简单 This is the Layout of the Activity

所以问题是方法“ instantiateItem（）”被调用了两次，这在我在该方法中调用随机函数及其创建过程中造成了问题两次不同的值，并且在第一次调用时会分配正确的视图，但下次不会更新视图。因此，请帮帮我，也请解释为什么它两次调用AnimalTestAdapter类。

XML设计

<?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">


<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"

    android:layout_margin="15dp"
    android:background="@drawable/slide_bg"
    android:elevation="4dp">

    <RelativeLayout
        android:id="@+id/rela1"
        android:layout_width="170dp"
        android:layout_height="170dp"
        android:layout_margin="10dp"
        android:elevation="2dp"
        android:background="@drawable/slide_bg">
        <ImageView
            android:id="@+id/imageanimaa"
            android:layout_width="match_parent"
            android:layout_height="483dp"
            android:src="@mipmap/a_for_apple" />
    </RelativeLayout>
    <RelativeLayout
        android:id="@+id/rela2"
        android:layout_width="170dp"
        android:layout_height="170dp"
        android:layout_margin="10dp"
        android:elevation="2dp"
        android:layout_alignParentRight="true"
        android:background="@drawable/slide_bg">
        <ImageView
            android:id="@+id/imageanimab"
            android:layout_width="match_parent"
            android:layout_height="483dp"
            android:src="@mipmap/b_for_ball" />
    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/rela3"
        android:layout_width="170dp"
        android:layout_height="170dp"
        android:layout_margin="10dp"
        android:elevation="2dp"
        android:layout_below="@+id/rela1"
        android:background="@drawable/slide_bg">
        <ImageView
            android:id="@+id/imageanimac"
            android:layout_width="match_parent"
            android:layout_height="483dp"
            android:src="@mipmap/b_for_ball" />
    </RelativeLayout>
    <RelativeLayout
        android:id="@+id/rela4"
        android:layout_width="170dp"
        android:layout_height="170dp"
        android:layout_margin="10dp"
        android:elevation="2dp"
        android:layout_below="@+id/rela2"
        android:layout_alignParentRight="true"
        android:background="@drawable/slide_bg">
        <ImageView
            android:id="@+id/imageanimad"
            android:layout_width="match_parent"
            android:layout_height="483dp"
            android:src="@mipmap/b_for_ball" />
    </RelativeLayout>
</RelativeLayout>
</RelativeLayout>

AdapterClass

package com.example.akroc.edversity;

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v4.view.PagerAdapter;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import java.util.ArrayList;
import java.util.Collections;

public class AnimalTestAdapter extends PagerAdapter {


    Context context;
    LayoutInflater layoutInflater;
    int randIndex;
    public int Answer;
    final String TAG="yowag";

    public AnimalTestAdapter(Context context) {
        this.context = context;
    }

    public int[] slideImages = {
            R.mipmap.idog,
            R.mipmap.icow,
            R.mipmap.ipeacock,
            R.mipmap.a_for_apple

    };

    public String[] slideHead = {

            "dog", "cow", "peacock","hint"
    };
    public int[] animalSound=
            {
                    R.raw.dog,
                    R.raw.cow,
                    R.raw.peacock,
                    R.raw.hint
            };

    @Override
    public int getCount() {
        return slideHead.length;
    }

    public int[] getRandom()
    {
        int[] randomval= new int[4];
        ArrayList<Integer> list = new ArrayList<Integer>();
        for (int i=0; i<slideHead.length; i++) {
            list.add(new Integer(i));
        }
        Collections.shuffle(list);
        for (int i=0; i<4; i++) {
            randomval[i]=list.get(i);
        }
        return  randomval;
    }

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

    @NonNull
    @Override
    public Object instantiateItem(@NonNull ViewGroup container, int position) {

        layoutInflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
        final View view = layoutInflater.inflate(R.layout.anitest_layout, container, false);
        final ImageView img1 = (ImageView) view.findViewById(R.id.imageanimaa);
        final ImageView img2 = (ImageView) view.findViewById(R.id.imageanimab);
        final ImageView img3 = (ImageView) view.findViewById(R.id.imageanimac);
        final ImageView img4 = (ImageView) view.findViewById(R.id.imageanimad);
        int[]temp=getRandom();
        img1.setImageResource(slideImages[temp[0]]);
        img2.setImageResource(slideImages[temp[1]]);
        img3.setImageResource(slideImages[temp[2]]);
        img4.setImageResource(slideImages[temp[3]]);

        randIndex=((int)(Math.random() * 4)); //0
        Answer=temp[randIndex]; //2
        Log.i(TAG,"Randomvalue: "+temp[0]+","+temp[1]+","+temp[2]+","+temp[3]+"Randindex "+randIndex+"Answer "+ Answer);

        container.addView(view);
        return view;
    }

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

Logcat

com.example.akroc.edversity I / yowag：随机值：2,0,3,1Randindex 3回答1 com.example.akroc.edversity I / yowag：随机值： 3,0,1,2Randindex 2答案1

PagerAdapter被调用两次

0 个答案: