如何使用viewHolder使listView用戶輸入不會回滾到默認時滾動屏幕

Question

我有一個listView，用戶可以在其中輸入輸入來更改每個listView行上的textView。當您將該行從屏幕上滾動時，編輯後的文本將消失，並重新顯示默認文本。我知道這是用viewHolder修復的，但我無法讓它在我的自定義適配器類中工作。

MainActivity.java

import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.app.Activity; 
import android.view.KeyEvent; 
import android.view.View; 
import android.view.inputmethod.EditorInfo; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.ListAdapter; 
import android.widget.ListView; 
import android.widget.TextView; 
import android.widget.Toast; 
import android.widget.ViewSwitcher; 

import java.util.ArrayList; 

public class MainActivity extends Activity { 


    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     final ArrayList<String> Chores = new ArrayList<>(); 
     //Chores.add(""); 

     final ListAdapter MyAdapter = new CustomAdapter(this, Chores); 
     ListView listViewObject = (ListView)findViewById(R.id.customListView_ID); 
     listViewObject.setAdapter(MyAdapter); 

     listViewObject.setOnItemClickListener(
      new AdapterView.OnItemClickListener(){ 
       @Override 
       public void onItemClick(AdapterView<?> parent, View view, int position, long id){ 
        String ChoreString = String.valueOf(parent.getItemAtPosition(position)); 




       } 
      } 

     ); 
     final Button button = (Button) findViewById(R.id.button_ID); 
     button.setOnClickListener(new View.OnClickListener() { 
      public void onClick(View v) { 
       Chores.add(""); 
       ((ArrayAdapter)MyAdapter).notifyDataSetChanged(); 

      } 

     }); 




    } 
} 

CustomAdapter.java

import android.content.Context; 
import android.content.DialogInterface; 
import android.support.annotation.NonNull; 
import android.support.v7.app.AlertDialog; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ArrayAdapter; 
import android.widget.EditText; 
import android.widget.ImageButton; 
import android.widget.ImageView; 
import android.widget.TextView; 

import java.util.ArrayList; 

import static com.example.emilythacker.chorelist.R.id.textView_ID; 



class CustomAdapter extends ArrayAdapter{ 

    ArrayList<String> choreText; 

    public CustomAdapter(Context context, ArrayList choreText) { 
     super(context, R.layout.custon_listview_row, choreText); 
     this.choreText = choreText; 
    } 

    @NonNull 
    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     final ViewHolder holder; 

     //final TextView textView = (TextView) customView.findViewById(textView_ID); 

     if (convertView == null) { 
      LayoutInflater layoutInflater = LayoutInflater.from(getContext()); 
      convertView = layoutInflater.inflate(R.layout.custon_listview_row, null); 
      holder = new ViewHolder(); 
      holder.imageButton = (ImageButton) convertView.findViewById(R.id.imageButton_ID); 
      holder.textView = (TextView) convertView.findViewById(textView_ID); 
      convertView.setTag(holder); 
     } else { 
      holder = (ViewHolder) convertView.getTag(); 
     } 

     holder.textView.setText(choreText.get(position)); 
     holder.textView.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       //what happens when textView is clicked 
       AlertDialog alertDialog = new AlertDialog.Builder(getContext()).create(); 
       final EditText input = new EditText(getContext()); 
       input.setHint("hint"); 
       alertDialog.setView(input); 
       alertDialog.setTitle("Set Chore"); 
       alertDialog.setMessage("Alert message to be shown"); 
       alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK", new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int which) { 




         holder.textView.setText(input.getText().toString()); 





         dialog.dismiss(); 
        } 
       }); 
       alertDialog.show(); 

      } 
     }); 



     holder.imageButton.setImageResource(R.drawable.clock); 


     return convertView; 
    } 

    static class ViewHolder { 
     ImageButton imageButton; 
     TextView textView; 
    } 
} 

activity_main.xml中

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:id="@+id/activity_main" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    tools:context="com.example.emilythacker.chorelist.MainActivity"> 

    <ListView 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:id="@+id/customListView_ID" 
     android:layout_alignParentTop="true" 
     android:layout_alignParentStart="true" 
     android:layout_marginTop="50dp" /> 

    <Button 
     android:text="Add Chore" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentTop="true" 
     android:layout_alignParentStart="true" 
     android:id="@+id/button_ID" /> 
</RelativeLayout> 

custon_listview_row.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    android:orientation="horizontal" android:layout_width="match_parent" 
    android:layout_height="60dp"> 

    <ImageButton 
     android:layout_width="60dp" 
     android:scaleType="fitCenter" 
     app:srcCompat="@drawable/clock" 
     android:id="@+id/imageButton_ID" 
     android:layout_height="60dp" 
     android:background="@null" 
     android:layout_alignParentRight="true" 
     android:padding="5dp" 
     android:layout_weight="1" /> 


    <TextView 
     android:text="Click here to add chore" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:ems="10" 
     android:id="@+id/textView_ID" 
     android:textSize="25dp" 
     android:layout_centerVertical="true" 
     android:layout_toStartOf="@+id/imageButton_ID" 
     android:layout_marginEnd="11dp" 
     /> 


</RelativeLayout> 

Answer 1

將文本輸入編輯文本時，需要將其保存到與該位置關聯的變量中，並且在getView中，您需要將editText的文本設置爲該位置的值。否則，你只會有最後一個隨機值。

基本上，任何可以在一個行的UI中改變的值都必須保存並寫入到getView中。