如何通過界面編輯ListView中的項目

Question

我有一個列表視圖（如下所示），它具有成分列表以及每個項目具有多少成分。我怎樣才能做到這一點，所以有一種方法可以在點擊每種成分時編輯數字值？

上下文菜單，並警告對話框，到目前爲止，我也算是按鈕相匹配的項目，但發現它沒有與無限的列表視圖工作。感謝任何幫助我的人！

Answer 1

如果你想保存這些值，那麼你可以創建一個子類並創建這個子類的列表。 您可以使用onItemClickListner來更新對象中的值，然後在適配器上執行notifydatasetchange，這將實現此功能。

或

另外，您可以通過這兩個列表中的適配器和更新要更新並做notifydatasetchange列表。

爲e.g.:-

//MainActivity 
public class MainActivity extends AppCompatActivity { 

ListView recView; 
ArrayList<Childclass> chobj=new ArrayList<>(); 

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

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

    chobj.add(new Childclass("Tomato sauce","0.0")); 
    chobj.add(new Childclass("Chicken","0.0")); 
    chobj.add(new Childclass("Olives","0.0")); 

    ListAdapter lstadptr=new ListAdapter(MainActivity.this,chobj); 
    recView.setAdapter(lstadptr); 

    recView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
     @Override 
     public void onItemClick(AdapterView<?> parent, View view, final int position, long id) { 

      AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(MainActivity.this); 
      LayoutInflater inflater = MainActivity.this.getLayoutInflater(); 
      final View dialogView = inflater.inflate(R.layout.custom_dialog, null); 
      dialogBuilder.setView(dialogView); 

      final EditText edt = (EditText) dialogView.findViewById(R.id.edit1); 

      dialogBuilder.setTitle("Custom dialog"); 
      dialogBuilder.setMessage("Enter text below"); 
      dialogBuilder.setPositiveButton("Add", new DialogInterface.OnClickListener() { 
       public void onClick(DialogInterface dialog, int whichButton) { 
        //do something with edt.getText().toString(); 
        chobj.get(position).setQuantity(edt.getText().toString()); 
        ((ListAdapter) recView.getAdapter()).notifyDataSetChanged(); 
       } 
      }); 
      dialogBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() { 
       public void onClick(DialogInterface dialog, int whichButton) { 
        //pass 
       } 
      }); 
      AlertDialog b = dialogBuilder.create(); 
      b.show(); 

     } 
    }); 

}} 

子類

public class Childclass { 

String name; 
String quantity; 

public String getName() { 
    return name; 
} 

public void setName(String name) { 
    this.name = name; 
} 

public String getQuantity() { 
    return quantity; 
} 

public void setQuantity(String quantity) { 
    this.quantity = quantity; 
} 

public Childclass(String name, String quantity) { 

    this.name = name; 
    this.quantity = quantity; 
}} 

ListAdapter

public class ListAdapter extends ArrayAdapter { 

ArrayList<Childclass> chobj; 
Context context; 

public ListAdapter(@NonNull Context context,ArrayList<Childclass> chobj) { 
    super(context, R.layout.recyclerow, chobj); 
    this.context = context; 
    this.chobj = chobj; 
} 

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

    View v; 
    LayoutInflater inflater = LayoutInflater.from(getContext()); 
    v = inflater.inflate(R.layout.recyclerow, parent, false); 
    TextView tv= (TextView) v.findViewById(R.id.txtrow); 
    TextView tv1= (TextView) v.findViewById(R.id.txtrow1); 

    tv.setText(chobj.get(position).getName()); 
    tv1.setText(chobj.get(position).getQuantity()); 

    return v; 
}} 

活動主

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:app="http://schemas.android.com/apk/res-auto" 
xmlns:tools="http://schemas.android.com/tools" 
android:orientation="vertical" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
tools:context="com.example.abhishek.kotlinprojecttest.MainActivity"> 


<ListView 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:background="#f2f2f2" 
    android:paddingTop="10dp" 
    android:id="@+id/recView"> 

</ListView> 

定製警報

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:padding="10dp" 
android:orientation="vertical"> 

<EditText 
    android:id="@+id/edit1" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:inputType="text" /> 

列表行

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:app="http://schemas.android.com/apk/res-auto" 
android:orientation="vertical" 
android:layout_width="match_parent" 
android:layout_height="wrap_content"> 

<android.support.v7.widget.CardView 
    android:layout_width="match_parent" 
    android:layout_height="50dp" 
    android:layout_marginLeft="10dp" 
    android:layout_marginRight="10dp" 
    android:layout_marginBottom="3dp" 
    android:layout_marginTop="3dp" 
    android:id="@+id/rowcd"> 

    <TextView 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:text="listTExt" 
     android:id="@+id/txtrow" 
     android:textColor="#000000" 
     android:textSize="16sp" 
     android:gravity="center"/> 
    <TextView 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:text="listTExt" 
     android:id="@+id/txtrow1" 
     android:textColor="#000000" 
     android:textSize="16sp" 
     android:gravity="center"/> 

</android.support.v7.widget.CardView> 

希望這將幫助你