單擊ListView項上的Button時，最后一項的狀態會發生變化

嘿，所以目標是當單擊串列項的按鈕取消時，該專案的狀態必須顯示為“已取消”并且按鈕變為黑色。但是，當按下按鈕時，按鈕會變黑，但串列項不會改變狀態。相反，視圖串列的最后一個按鈕會更改狀態。你能幫我嗎？

配接器類：

package com.example.myappfinal.Adapter;

import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.core.graphics.drawable.DrawableCompat;

import com.example.myappfinal.Logic.Appointment;
import com.example.myappfinal.R;

import java.util.ArrayList;


public class AppointmentListAdapter extends ArrayAdapter<Appointment> {

    private String state,date,time;
    private TextView stateT,dateT,timeT;
    private Context mContext;
    int mRecource;


    public AppointmentListAdapter(@NonNull Context context, int resource, @NonNull ArrayList<Appointment> objects) {
        super(context, resource, objects);
        mContext=context;
        mRecource=resource;
    }

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


        state=getItem(position).getState();
        String service=getItem(position).getService().getName();
        date = getItem(position).getDate();
        time = getItem(position).getStartTime();

        LayoutInflater inflater = LayoutInflater.from(mContext);
        convertView = inflater.inflate(mRecource,parent,false);

        stateT = (TextView) convertView.findViewById(R.id.state);
        TextView serviceT = (TextView) convertView.findViewById(R.id.service);
        TextView dateT = (TextView) convertView.findViewById(R.id.date);
        TextView timeT = (TextView) convertView.findViewById(R.id.time);


        stateT.setText(state);
        serviceT.setText(service);
        dateT.setText(date);
        timeT.setText(time);

        Button button =(Button)convertView.findViewById(R.id.button);
        if(state.equals("Canceled")){
            Drawable buttonDrawable = button.getBackground();
            buttonDrawable = DrawableCompat.wrap(buttonDrawable);
            DrawableCompat.setTint(buttonDrawable, Color.BLACK);
            button.setBackground(buttonDrawable);
        }

            button.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    //do something
                    if(state.equals("Active")) {
                        getItem(position).cancel();
                        state = getItem(position).getState();
                        stateT.setText(state);

                        Drawable buttonDrawable = button.getBackground();
                        buttonDrawable = DrawableCompat.wrap(buttonDrawable);
                        DrawableCompat.setTint(buttonDrawable, Color.BLACK);
                        button.setBackground(buttonDrawable);
                    }

                }

            });

        return convertView;

    }

uj5u.com熱心網友回復：

問題是stateT配接器中的一個類成員，您為每一行的getView呼叫覆寫它，因此在填充串列后，它總是參考最后一行。您不應該將視圖（例如stateT）保存為類成員。每次呼叫都getView將覆寫那里保存的先前值。

對于您的情況，您可能應該做這樣的事情（如果沒有完整的代碼，很難確定）

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

    // Don't re-inflate unless necessary
    if( convertView == null ) {
        LayoutInflater inflater = LayoutInflater.from(mContext);
        convertView = inflater.inflate(mRecource,parent,false);
    }

    // Get the state of the current row
    Appointment appt = getItem(position);
    String state = appt.getState();
    String service = appt.getService().getName();
    String date = appt.getDate();
    String time = appt.getStartTime();
        
    // These should NOT be class members
    TextView stateT = convertView.findViewById(R.id.state);
    TextView serviceT = convertView.findViewById(R.id.service);
    TextView dateT = convertView.findViewById(R.id.date);
    TextView timeT = convertView.findViewById(R.id.time);

    // Set the row's values
    stateT.setText(state);
    serviceT.setText(service);
    dateT.setText(date);
    timeT.setText(time);

    Button button = convertView.findViewById(R.id.button);
    
    if(state.equals("Canceled")){
        Drawable buttonDrawable = button.getBackground();
        buttonDrawable = DrawableCompat.wrap(buttonDrawable);
        DrawableCompat.setTint(buttonDrawable, Color.BLACK);
        button.setBackground(buttonDrawable);
 
        // may also want to disable the button
        button.setEnabled(false);
    }
    else {
        button.setEnabled(true);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // get the current row state - since it may have been
                // updated since the listener was created
                String rowState = appt.getState();
                
                if(rowState.equals("Active")) {
                    appt.cancel();
                    String newState = appt.getState();

                    // stateT here refers to just this row's TextView now
                    stateT.setText(newState);

                    Drawable buttonDrawable = button.getBackground();
                    buttonDrawable = DrawableCompat.wrap(buttonDrawable);
                    DrawableCompat.setTint(buttonDrawable, Color.BLACK);
                    button.setBackground(buttonDrawable);

                    // may also want to disable the button
                    button.setEnabled(false);
                }
            }
        });
    }

    return convertView;
}

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