Java 我制作了一个列表视图的自定义适配器，但它给出了空指针异常

这是我的活动：

        public class TopReviews extends AppCompatActivity {

            public static String[] item_name={"Shoes","Shirts","Jeans","T-Shirts","Suite"};
           // public static String[] item_quantity={"2","4","3","2","8"};
            public static String [] item_description ={"Aqwer tyuffds","ABCSas fdkdfjsd","JAVA 12345669sd","assdecd Jsp","Microsoft band kro .Net"};
            public static String [] item_username ={"Ali","Bashir","Ahsan","Abubakar","Shani"};



            ListView lv;
            Context context1;


            protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_top_reviews);

                context1=this;

                lv=(ListView) findViewById(R.id.reviews_listview);

    **//I Always got the null point exception on the line below...**

                lv.setAdapter(new ReviewsAdapterForReviews(context1,item_name,item_name,item_name));

            }  
        }

package com.app.beautysaloon;

import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.*;


public class ReviewsAdapterForReviews extends ArrayAdapter<String> {


    String[] i_name,i_username,i_description;
    LayoutInflater inflater;
    Context context123;
    public static Intent i;
    ViewHolder holder;
    public ReviewsAdapterForReviews(Context context, String[] item_name,String[]item_description,String[]item_username) {

        super(context, R.layout.activity_top_reviews,item_name
        );
        // TODO Auto-generated constructor stub
        context123=context;
        i_name=item_name;
        i_username=item_username;
        i_description=item_description;
    }
    public class ViewHolder {
        TextView item_name,item_description,item_username;
    }
    @Override
    public View getView(final int position, View convertView,
                        ViewGroup parent) {
        // TODO Auto-generated method stub

        if(convertView==null){
            inflater=LayoutInflater.from(context123);
            convertView=inflater.inflate
                    (R.layout.activity_top_reviews,null);
        }

        holder=new ViewHolder();

        holder.item_name=(TextView) convertView.findViewById
                (R.id.saloonname_tv);
        holder.item_description=(TextView) convertView.findViewById
                (R.id.reviews_description_tv);
        holder.item_username = (TextView) convertView.findViewById
                (R.id.username_tv);


        holder.item_name.setText(i_name[position]);
        holder.item_description.setText(i_description[position]);
        holder.item_username.setText(i_username[position]);

        return convertView;
    }
}

这是我的适配器类：

        public class TopReviews extends AppCompatActivity {

            public static String[] item_name={"Shoes","Shirts","Jeans","T-Shirts","Suite"};
           // public static String[] item_quantity={"2","4","3","2","8"};
            public static String [] item_description ={"Aqwer tyuffds","ABCSas fdkdfjsd","JAVA 12345669sd","assdecd Jsp","Microsoft band kro .Net"};
            public static String [] item_username ={"Ali","Bashir","Ahsan","Abubakar","Shani"};



            ListView lv;
            Context context1;


            protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_top_reviews);

                context1=this;

                lv=(ListView) findViewById(R.id.reviews_listview);

    **//I Always got the null point exception on the line below...**

                lv.setAdapter(new ReviewsAdapterForReviews(context1,item_name,item_name,item_name));

            }  
        }

package com.app.beautysaloon;

import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.*;


public class ReviewsAdapterForReviews extends ArrayAdapter<String> {


    String[] i_name,i_username,i_description;
    LayoutInflater inflater;
    Context context123;
    public static Intent i;
    ViewHolder holder;
    public ReviewsAdapterForReviews(Context context, String[] item_name,String[]item_description,String[]item_username) {

        super(context, R.layout.activity_top_reviews,item_name
        );
        // TODO Auto-generated constructor stub
        context123=context;
        i_name=item_name;
        i_username=item_username;
        i_description=item_description;
    }
    public class ViewHolder {
        TextView item_name,item_description,item_username;
    }
    @Override
    public View getView(final int position, View convertView,
                        ViewGroup parent) {
        // TODO Auto-generated method stub

        if(convertView==null){
            inflater=LayoutInflater.from(context123);
            convertView=inflater.inflate
                    (R.layout.activity_top_reviews,null);
        }

        holder=new ViewHolder();

        holder.item_name=(TextView) convertView.findViewById
                (R.id.saloonname_tv);
        holder.item_description=(TextView) convertView.findViewById
                (R.id.reviews_description_tv);
        holder.item_username = (TextView) convertView.findViewById
                (R.id.username_tv);


        holder.item_name.setText(i_name[position]);
        holder.item_description.setText(i_description[position]);
        holder.item_username.setText(i_username[position]);

        return convertView;
    }
}

package.com.app.beautysaloon；
导入android.content.Context；
导入android.content.DialogInterface；
导入android.content.Intent；
导入android.view.LayoutInflater；
导入android.view.view；
导入android.view.ViewGroup；
导入android.widget.AdapterView；
导入android.widget.ArrayAdapter；
导入android.widget.Button；
导入android.widget.TextView；
导入android.widget.Toast；
导入java.util.ArrayList；
导入java.util.array；
导入java.util.List；
导入java.util.stream.*；
公共类ReviewAdapterForreviews扩展了ArrayAdapter{
字符串[]i\u名称、i\u用户名、i\u描述；
充气机；
语境123；
公共静态意图i；
视窗座；
public Reviews AdapterForReviews（上下文上下文，字符串[]项\名称，字符串[]项\说明，字符串[]项\用户名）{
超级（上下文、右布局、活动、顶部评论、项目名称
);
//TODO自动生成的构造函数存根
context123=上下文；
i_name=项目名称；
i_用户名=项目_用户名；
i_描述=项目描述；
}
公共类视图持有者{
text查看项目名称、项目描述、项目用户名；
}
@凌驾
公共视图getView（最终整型位置，视图转换视图，
视图组（父级）{
//TODO自动生成的方法存根
if（convertView==null）{
充气机=从（上下文123）开始的充气机；
convertView=充气机。充气
（R.布局、活动和顶部审查，空）；
}
holder=新的ViewHolder（）；
holder.item_name=（TextView）convertView.findViewById
（R.id.saloonname_tv）；
holder.item_description=（TextView）convertView.findViewById
（R.id.reviews\u description\u tv）；
holder.item_username=（TextView）convertView.findViewById
（R.id.username_tv）；
持有人.项目名称.设置文本（项目名称[位置]）；
持有者.项目描述.设置文本（项目描述[位置]）；
holder.item_username.setText（i_username[position]）；
返回视图；
}
}

我只是试图将静态数据传递到活动的列表视图。 所以请帮我找出空指针异常在哪里。

---

我使用holder类获取这些文本视图，并在adapter类中传递相同的布局，但它在调用adapter类函数的列表视图中给出了空点异常。

很可能此调用返回

null

：

findViewById(R.id.reviews_listview)

---

这意味着没有这样的视图。

可能重复的我无法在我的代码中找到异常堆栈跟踪具有异常发生的行号。setContentView（R.layout.activity\u top\u reviews）；取而代之的是我通过了这个setContentView（R.layout.reviews\u listview）；