Question

这是我的arrayAdapter，我有两个文本字段，“imgen”和“txtTitle”。目前我将以下文本设置为arrayAdapter

中的“imgen”textView

holder.imgIcon.setText(Double.toString(weather.getBuyingRate()));

以下是适配器。

package com.example.mainactivity;

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class WeatherAdapter extends ArrayAdapter<Weather>{

    Context context; 
    int layoutResourceId;    
    Weather data[] = null;



    public WeatherAdapter(Context context, int layoutResourceId, Weather[] data) {
        super(context, layoutResourceId, data);
        this.layoutResourceId = layoutResourceId;
        this.context = context;
        this.data = data;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;
        WeatherHolder holder = null;

        if(row == null)
        {
            LayoutInflater inflater = ((Activity)context).getLayoutInflater();
            row = inflater.inflate(layoutResourceId, parent, false);

            holder = new WeatherHolder();
            holder.imgIcon = (TextView)row.findViewById(R.id.imgen);
            holder.txtTitle = (TextView)row.findViewById(R.id.txtTitle);

            row.setTag(holder);
        }
        else
        {
            holder = (WeatherHolder)row.getTag();
        }

        Weather weather = data[position];
        holder.txtTitle.setText(weather.getName());
        holder.imgIcon.setText(Double.toString(weather.getBuyingRate()));

        return row;
    }

    static class WeatherHolder
    {
        TextView imgIcon;
        TextView txtTitle;
    }
}

根据用户是否按下按钮，我希望从主类更改此设置？我想在"setText(Double.toString(weather.getBuyingRate()));"和setText(Double.toString(weather.getNrOfSharesInPortfolio()));之间进行更改，具体取决于goButton当前的文本。请参阅下面的代码中的注释。

注意这将更新列表中每个元素的imgIcon。

有没有办法从MainActitivy访问“holder.imgIcon”？

这是我的MainActivity

package com.example.mainactivity;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ListView;

public class MainActivity extends Activity {

    private ListView listView1;
    private Button goButton;
    private String[] listheader = {"Köp Kurs","Antal"};
    int totalElemInlist = listheader.length;
    int currentelemInList=0;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Weather weather_data[] = new Weather[]
        {
            new Weather("ABB", 56.0, 300),
            new Weather("Volvo", 89.0,500),
            new Weather("Astra Zeneca", 98.55, 50)
        };

        WeatherAdapter adapter = new WeatherAdapter(this, 
                R.layout.listview_item_row, weather_data);


        listView1 = (ListView)findViewById(R.id.listView1);

        View header = (View)getLayoutInflater().inflate(R.layout.listview_header_row, null);
        listView1.addHeaderView(header);
        goButton = (Button) findViewById(R.id.testButton);
        goButton.setText(listheader[currentelemInList]);

        listView1.setAdapter(adapter);

        goButton.setOnClickListener(new OnClickListener() {
            public void onClick(View view) {
                String buttonPressed = (String) ((Button) view).getText();
                goThroughList(buttonPressed);
                System.out.println("Button Clicked" + buttonPressed);
            }
          });
    }

    private void goThroughList(String buttonPressed){
        currentelemInList++;
        if(currentelemInList>=totalElemInlist){
            currentelemInList=0;
        }
        goButton.setText(listheader[currentelemInList]);

        if(buttonPressed == "Köp Kurs"){
            System.out.println("Köp kurs");
            //holder.imgIcon.setText(Double.toString(weather.getBuyingRate()));
        }
        else if(buttonPressed == "Antal"){
            System.out.println("Antal");
            //holder.imgIcon.setText(Double.toString(weather.getNrOfSharesInPortfolio()));
        }




        System.out.println(currentelemInList);
    }
}

Answer 1

你有一个TextView imgIcon，它将显示buyRate或nrOfSharesInPortfolio。按下goButton时会切换显示。

public class WeatherAdapter extends ArrayAdapter<Weather>{

    // ...

    private String buttonPressed = "Köp Kurs";

    public void setButtonPressed(String s) {
        buttonPressed = s;
        notifyDataSetChanged();
    }

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

        // ... 

        Weather weather = data[position];
        holder.txtTitle.setText(weather.getName());

        if(buttonPressed == "Köp Kurs"){
            holder.imgIcon.setText(Double.toString(weather.getBuyingRate()));
        }
        else if(buttonPressed == "Antal"){
            holder.imgIcon.setText(Double.toString(weather.getNrOfSharesInPortfolio()));
        }

        return row;
    }

    // ...
}

在MainActivity.onCreate（）中，将点击侦听器上的goButton设置为：

goButton.setOnClickListener(new OnClickListener() {
    public void onClick(View view) {
        String buttonPressed = (String) ((Button) view).getText();
        adapter.setButtonPressed(buttonPressed);
    }
});

动态更新listadapter

1 个答案: