Java 自定义适配器处的NullPointerException'；在我添加启动屏幕后，s getView

这个适配器类一直运行良好；然而，当我添加一个启动屏幕并将启动屏幕作为启动程序活动启动时，这个适配器类在getView函数上给出了一个nullpointerexception

MYADAPTER.JAVA

package com.zoopoo.a_man.zoopoo;
import android.content.Context;    
import android.view.LayoutInflater;    
import android.view.View;    
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class MyAdapter extends BaseAdapter {
    Context context;
    String[] listItems;
    int[] images = {R.drawable.home, R.drawable.notification, R.drawable.gallery, R.drawable.about};

    public MyAdapter(Context context) {
        this.context = context;
        listItems = context.getResources().getStringArray(R.array.list_item);
    }

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

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        View row = null;
        if (view == null) {
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
            row = inflater.inflate(R.layout.custom_list, viewGroup, false);
        } else {
            row = viewGroup;
        }
        ImageView iv = (ImageView) row.findViewById(R.id.iv);
        TextView tv = (TextView) row.findViewById(R.id.tv);
        tv.setText(listItems[i]);  // error comes here..!!
        iv.setImageResource(images[i]);
        return row;
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @Override
    public Object getItem(int i) {
        return listItems[i];
    }
}

SPLASH.JAVA

package com.zoopoo.a_man.zoopoo;
import android.content.Intent;
import android.graphics.Typeface;
import android.os.Build;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.WindowManager;
import android.widget.TextView;

public class Splash extends ActionBarActivity {
    TextView tvsplash;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.splash);
        tvsplash = (TextView)findViewById(R.id.tvsplash);
        Typeface typeface = Typeface.createFromAsset(getAssets(),"fonts/DroidSerif-BoldItalic.ttf");
        tvsplash.setTypeface(typeface);

        Thread wait = new Thread(){
            public void run(){
                try{
                   sleep(3000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }finally {
                    Intent register = new Intent("com.zoopoo.a_man.zoopoo.MAINACTIVITY");
                    startActivity(register);
                }
            }
        };
        wait.start();
    }
}

ANDROIDMANIFEST.XML

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme">
        <activity
            android:name=".Splash"
            android:label="@string/app_name"
            android:theme="@style/FullScreen">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity
            android:name=".GcmRegister"
            android:label="zooPoo"
            android:theme="@android:style/Theme.NoTitleBar">
            <intent-filter>
                <action android:name="com.zoopoo.a_man.zoopoo.GCMREGISTER" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>

        <activity
            android:name=".MainActivity"
            android:label="@string/app_name"
            android:theme="@style/AppTheme">`enter code here`

<!-- Whenever i set this as launcher activity app runs fine, but when i launch this from splash activity, app crashes at MyAdapter's getView. -->

            <intent-filter>
                <action android:name="com.zoopoo.a_man.zoopoo.MAINACTIVITY" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
    </application>

</manifest>

---

适配器的getView（）中存在问题。您正在执行

row=viewGroup但它应该是
行=视图。如下:

    if (view == null) {
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
        row = inflater.inflate(R.layout.custom_list, viewGroup, false);
    } else {
        row = view; // CHECK THIS LINE!!!!!!
    }

视图
是到getView循环使用的convertView实例，如果它不为null，则可以重复使用，这就是代码的意图

当您执行
row=viewGroup时
，然后尝试
row.findViewById（R.id.tv）
，它将返回
null
，当您尝试
setText（）
时，您将获得NPE

希望这有帮助。：）
 给我们看看你的堆栈跟踪你能给我们看看你的主要活动吗？你开始活动的方式正确吗。。。这奏效了。。谢谢你，伙计我明白你的解释了！！：-）
    if (view == null) {
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
        row = inflater.inflate(R.layout.custom_list, viewGroup, false);
    } else {
        row = view; // CHECK THIS LINE!!!!!!
    }