根据listView单击更改EditText

Question

大家好我正在寻找一些帮助并建议我的应用程序，目前我有一个自定义适配器打印出每一行，每行打印两个按钮，一个按钮递增，一个按钮递减。我想要发生的是当单击一个按钮时，listView外部的editText（totalCost）发生了变化。我不知道如何去做这个，因为我对android和java很新，所以任何帮助都会很棒。感谢

我使用的自定义适配器是

package com.example.rory.dbtest;
import android.content.Context;
import android.database.Cursor;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.CursorAdapter;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;
import com.pinchtapzoom.R;


public class CustomCursorAdapter extends CursorAdapter{

    public int counter = 0;

    public CustomCursorAdapter(Context context, Cursor c) {

        super(context, c);
        this.context = context;
    }
    Context context;


    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        // when the view will be created for first time,
        // we need to tell the adapters, how each item will look
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
        View retView = inflater.inflate(R.layout.row, parent, false);

        return retView;
    }

    public void bindView(View view, Context context, Cursor cursor) {
        // here we are setting our data
        // that means, take the data from the cursor and put it in views
        TextView textViewPersonName = (TextView) view.findViewById(R.id.item1);
        textViewPersonName.setText(cursor.getString(cursor.getColumnIndex(cursor.getColumnName(1))));

        final EditText edit1 = (EditText) view.findViewById(R.id.runningTotal);

        Button plusButton = (Button) view.findViewById(R.id.plusButton);
        plusButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                counter++;
                edit1.setText(Integer.toString(counter));
            }
        });

        Button minusButton = (Button) view.findViewById(R.id.minusButton);
        minusButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                counter--;
                edit1.setText(Integer.toString(counter));
            }
        });
    }    
}

这是我希望editText（TotalCost）根据点击而改变的主要活动

import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.os.Handler;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;

import com.pinchtapzoom.R;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.SQLException;

public class MyActivity extends Activity {

    private CustomCursorAdapter customAdapter;
    public ListView list1;

    com.example.rory.dbtest.DBAdapter db = new com.example.rory.dbtest.DBAdapter(this);

    public EditText TotalCost;
    //public EditText TotalLitres;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);

        list1 = (ListView)findViewById(R.id.data_list);
        db.open();


        Button addBtn = (Button)findViewById(R.id.add);
        addBtn.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent i = new Intent(MyActivity.this, addassignment.class);
                startActivity(i);
            }
        });

        Button deleteBtn = (Button)findViewById(R.id.delete);
        deleteBtn.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent i = new Intent(MyActivity.this, Delete.class);
                startActivity(i);
            }
        });

        Button updateBtn = (Button)findViewById(R.id.update);
        updateBtn.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent i = new Intent(MyActivity.this, Update.class);
                startActivity(i);
            }
        });


        try {
            String destPath = "/data/data/" + getPackageName() + "/databases/AssignmentDB";
            File f = new File(destPath);
            if (!f.exists()) {
                CopyDB( getBaseContext().getAssets().open("mydb"),
                        new FileOutputStream(destPath));
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }


       new Handler().post(new Runnable() {
            @Override
            public void run() {
                //Log.d("test", "customadapter is " + customAdapter.toString());
                //Log.d("test", "databaseHelper is " + databaseHelper.toString());
                customAdapter = new CustomCursorAdapter(MyActivity.this, db.getAllRecords());
                list1.setAdapter(customAdapter);
            }
        });


    }

    private class DBAdapter extends BaseAdapter {
        private LayoutInflater mInflater;
        //private ArrayList<>

        @Override
        public int getCount() {

            return 0;
        }

        @Override
        public Object getItem(int arg0) {

            return null;
        }

        @Override
        public long getItemId(int arg0) {

            return 0;
        }

        @Override
        public View getView(int arg0, View arg1, ViewGroup arg2) {

            return null;
        }

    }

    public void CopyDB(InputStream inputStream, OutputStream outputStream)
            throws IOException {
        //---copy 1K bytes at a time---
        byte[] buffer = new byte[1024];
        int length;
        while ((length = inputStream.read(buffer)) > 0) {
            outputStream.write(buffer, 0, length);
        }
        inputStream.close();
        outputStream.close();
    }
}

适配器的XML文件

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">

    <TextView android:id="@+id/item1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="item"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:textSize="30sp"
        android:paddingBottom="5dp"/>

    <Button
        android:id="@+id/plusButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/plusButton"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true" />

    <EditText
        android:id="@+id/runningTotal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_toLeftOf="@+id/minusButton"
        android:layout_toStartOf="@+id/minusButton"
        android:layout_marginRight="30dp" />

    <Button
        android:id="@+id/minusButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/minusButton"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true" />



</RelativeLayout>

Answer 1

您应该使用界面

1）创建一个接口类：

public interface MyAdapterInterface {
    public void updateEditText(String value);
}

2）将适配器更改为：

public class CustomCursorAdapter extends CursorAdapter{

    public int counter = 0;
    private MyAdapterInterface mMyInterface;

    public CustomCursorAdapter(Context context, Cursor c,  MyAdapterInterface myInterface) {

        super(context, c);
        this.context = context;
        this.mMyInterface = myInterface;
    }
    Context context;


    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        // when the view will be created for first time,
        // we need to tell the adapters, how each item will look
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
        View retView = inflater.inflate(R.layout.row, parent, false);

        return retView;
    }

    public void bindView(View view, Context context, Cursor cursor) {
        // here we are setting our data
        // that means, take the data from the cursor and put it in views
        TextView textViewPersonName = (TextView) view.findViewById(R.id.item1);
        textViewPersonName.setText(cursor.getString(cursor.getColumnIndex(cursor.getColumnName(1))));

        final EditText edit1 = (EditText) view.findViewById(R.id.runningTotal);

        Button plusButton = (Button) view.findViewById(R.id.plusButton);
        plusButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                counter++;
                edit1.setText(Integer.toString(counter));
                mMyInterface.updateEditText(/*YOUR VALUE*/);
            }
        });

        Button minusButton = (Button) view.findViewById(R.id.minusButton);
        minusButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                counter--;
                edit1.setText(Integer.toString(counter));
                mMyInterface.updateEditText(/*YOUR VALUE*/);
            }
        });
    }    
}

3）在你的活动中实现界面：

public class MyActivity extends Activity implements MyAdapterInterface {

    private CustomCursorAdapter customAdapter;
    public ListView list1;

    com.example.rory.dbtest.DBAdapter db = new com.example.rory.dbtest.DBAdapter(this);

    public EditText TotalCost;
    //public EditText TotalLitres;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);

        list1 = (ListView)findViewById(R.id.data_list);
        db.open();


        Button addBtn = (Button)findViewById(R.id.add);
        addBtn.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent i = new Intent(MyActivity.this, addassignment.class);
                startActivity(i);
            }
        });

        Button deleteBtn = (Button)findViewById(R.id.delete);
        deleteBtn.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent i = new Intent(MyActivity.this, Delete.class);
                startActivity(i);
            }
        });

        Button updateBtn = (Button)findViewById(R.id.update);
        updateBtn.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent i = new Intent(MyActivity.this, Update.class);
                startActivity(i);
            }
        });


        try {
            String destPath = "/data/data/" + getPackageName() + "/databases/AssignmentDB";
            File f = new File(destPath);
            if (!f.exists()) {
                CopyDB( getBaseContext().getAssets().open("mydb"),
                        new FileOutputStream(destPath));
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }


       new Handler().post(new Runnable() {
            @Override
            public void run() {
                //Log.d("test", "customadapter is " + customAdapter.toString());
                //Log.d("test", "databaseHelper is " + databaseHelper.toString());
                customAdapter = new CustomCursorAdapter(MyActivity.this, db.getAllRecords(), this);
                list1.setAdapter(customAdapter);
            }
        });

        @Override
            public void updateEditText(String value) {
                EditText myEditText = (EditText)findViewById(R.id./*YOUR EDITTEXT ID*/);
                myEditText.setText(value);
        }
    }

    private class DBAdapter extends BaseAdapter {
        private LayoutInflater mInflater;
        //private ArrayList<>

        @Override
        public int getCount() {

            return 0;
    }

        @Override
        public Object getItem(int arg0) {

            return null;
        }

        @Override
        public long getItemId(int arg0) {

            return 0;
        }

        @Override
        public View getView(int arg0, View arg1, ViewGroup arg2) {

            return null;
        }

    }

    public void CopyDB(InputStream inputStream, OutputStream outputStream)
            throws IOException {
        //---copy 1K bytes at a time---
        byte[] buffer = new byte[1024];
        int length;
        while ((length = inputStream.read(buffer)) > 0) {
            outputStream.write(buffer, 0, length);
        }
        inputStream.close();
        outputStream.close();
    }
}