如何在我的自定义Android ListView中替换文本？

Question

我有一个自定义ListView，其中每个项目都有3列，我希望通过单击按钮来替换指定项目的文本。

这是代码：

CustomUsersAdapter.java

import java.util.ArrayList;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.TextView;


public class CustomUsersAdapter extends ArrayAdapter<User> {
    public CustomUsersAdapter(Context context, ArrayList<User> users) {
        super(context, 0, users);

    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {


        // Check if an existing view is being reused, otherwise inflate the view
        if (convertView == null) {
            convertView = LayoutInflater.from(getContext()).inflate(R.layout.lv_player, parent, false);
        }

        // Get the data item for this position
        User user = getItem(position);



        // Lookup view for data population
        TextView tvName = (TextView) convertView.findViewById(R.id.name);
        TextView tvHome = (TextView) convertView.findViewById(R.id.hometown);
        TextView CHid = (TextView) convertView.findViewById(R.id.id);


        // Populate the data into the template view using the data object
        tvName.setText(user.getName());
        tvHome.setText(user.getHometown());
        CHid.setText(user.getId());

        return convertView;
    }
}

User.java

public class User {

    //declare private data instead of public to ensure the privacy of data field of each class
    private String name;
    private String hometown;
    private String id;


    public User(String name, String hometown, String id ) {
        this.name = name;
        this.hometown = hometown;
        this.id = id;

    }

    //retrieve user's name
    public String getName(){
        return name;
    }

    //retrieve users' hometown
    public String getHometown(){
        return hometown;
    }

    //retrieve users' id
    public String getId(){
        return id;
    }

}

MainActivity.java

private ArrayAdapter<String> adapter;
ArrayList<User> users = new ArrayList<User>();

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

users.add( new User( "Alex", "Geneva", "1") );
users.add( new User( "Paul", "Paris", "2") );
users.add( new User( "Joe", "New-York", "3") );
....


    CustomUsersAdapter adapter = new CustomUsersAdapter( this, users );
    listView.setAdapter( adapter );

所以我如何替换项目内容？我想通过单击按钮来替换特定项目的名称和家乡。

我尝试了一些代码，例如：

ReplaceItem.setOnClickListener( new View.OnClickListener() {
    @Override
    public void onClick(View view) {

    users[3].add( new User( "Marco", "Barcelona" "3" ) ); 
    or 
    users.add( new User[3]( "Marco", "Barcelona" "3" ) )

但是很好，这行不通。我对Android Studio不满意，如果答案很简单，请对不起。对不起，我的英语不好。

Answer 1

您的ListView和适配器很好。我认为问题是由您实现Click侦听器的方式引起的。另外，您需要像这样在User.java中添加setter方法：

 public class User {

//declare private data instead of public to ensure the privacy of data field of each class
private String name;
private String hometown;
private String id;


public User(String name, String hometown, String id ) {
    this.name = name;
    this.hometown = hometown;
    this.id = id;

}

//retrieve user's name
public String getName(){
    return name;
}

//set user's name
public void setName(String name){
    this.name = name;
}

//retrieve users' hometown
public String getHometown(){
    return hometown;
}

//set user's hometown
public void setHometown(String hometown){
    this.hometown= hometown;
}

//retrieve users' id
public String getId(){
    return id;
}

//set users' id
public void setId(String id){
    this.id = id;
}

}

 listView.setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
    //MODFIFY YOUR ARRAY HERE
    users.get(position).setName("new name");
    users.get(position).setHometown("new hometown");
    users.get(position).setId("new id");
    adapter.notifyDataSetChanged(); //THIS LINE IS VERY IMPORTANT AFTER YOU ARE DONE MODIFYING            
 }
});