单击列表视图中自定义单元格中按钮的侦听器

Question

我为我的 Android 应用程序创建了一个自定义列表视图，以便为每个单元格添加一个删除按钮，使用户能够从列表中删除行。 自定义列表视图运行良好，但是当我为按钮添加单击侦听器时，列表视图显示空单元格而不是填充来自数组的数据。 这是 getView 代码：

public View getView(final int position, View convertView, ViewGroup parent) {
        LayoutInflater inflater = getLayoutInflater();
        View row = inflater.inflate(R.layout.row, parent, false);
        Button deleteButt = (Button) row.findViewById(R.id.deleteButton);
        deleteButt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(getActivity(), "delete me", Toast.LENGTH_SHORT).show();
            }
        });
        return row;
    }

我认为我应该返回其他东西而不是行，但我不知道该返回什么。 当我返回行时考虑它时，它应该显示填充了数据的行。 请注意，当我删除这段代码时，列表视图可以很好地显示数据。

这是适配器类的全部代码

// Our adapter class
class MyAdapter extends ArrayAdapter<String> {
    Context context;
    String rNames[];


    MyAdapter(Context c, String name[]) {
        super(c, R.layout.row, R.id.customerName, name);
        this.context = c;
        this.rNames = name;

    }

    public View getView(final int position, View convertView, ViewGroup parent) {
        LayoutInflater inflater = getLayoutInflater();
        View row = inflater.inflate(R.layout.row, parent, false);
        Button deleteButt = (Button) row.findViewById(R.id.deleteButton);
        deleteButt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(getActivity(), "delete me", Toast.LENGTH_SHORT).show();
            }
        });
        return row;
    }
    
}

这是主页片段页面的全部代码

public class HomeFragment extends Fragment {

    // creating an empty array. This is an array of objects (array of arrays).
    final ArrayList<String[]> mainObjectsArray = new ArrayList<String[]>();
    //final String[][] myFamily = new String[][];

    // creating another array of the titles. If our main array is an array of strings we will not need this.
    // Why?. ArrayAdapter doesn't accept an array of arrays it only accepts an array of Stings, so we had to create a special array for the titles and bring them from our main array.
    final ArrayList<String> theNames = new ArrayList<String>();

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        final View rootView =  inflater.inflate(R.layout.fragment_home, null);


        // creaing a list view and connect it to the list view we created in the XML file
        // Note: we need to add (final) to be able to access them from inside the loop
        final ListView myListView = (ListView) rootView.findViewById(R.id.myListView);


        // Retrieving the data and filling the array with it
        ParseQuery<ParseObject> query = ParseQuery.getQuery("Orders");
        query.orderByDescending("updatedAt");
        query.findInBackground(new FindCallback<ParseObject>() {
            @Override
            public void done(List<ParseObject> objects, ParseException e) {
                if (e == null) {
                    //Log.i("findInBackground", "Retrieved: " + objects.size() + "objects");
                    if (objects.size() > 0) {
                        for (ParseObject object: objects) {

                            // Converting every object to an array of two itmes, title and body.
                            String[] artical = {object.getString("TheSavedOrder"), object.getString("mobileNumber"), object.getString("Name")};

                            // Adding the array to our main array so we will have an array of arrays
                            mainObjectsArray.add(artical);

                            //Log.i("This my family array: ", myFamily.toString());

                        }

                        // We will add only the names to the array (theNames). theTitles will be an array of strings so we can populate it in the list view.
                        for (int i = 0; i < mainObjectsArray.size(); i++){
                            theNames.add(mainObjectsArray.get(i)[2]);
                            //Log.i("Here are teh title: ", myFamily.get(i)[0]);
                            Log.i("Here is thti: ", theNames.get(i));
                        }


                        // Converting theNames from ArrayList to an array
                        String[] namesArray = new String[theNames.size()];
                        namesArray = theNames.toArray(namesArray);

                        // Applaying our adapter
                        MyAdapter adapter = new MyAdapter(getActivity(), namesArray);
                        myListView.setAdapter(adapter);

                    }
                }
            }
        });

        // When clicking on an item in the list view
        myListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //Log.i("The body is: ", mainObjectsArray.get(position));
                Intent intent = new Intent(getContext(), TheBody.class);
                intent.putExtra("mobile", mainObjectsArray.get(position)[1]);  // mainObjectsArray.get(position)[1] means we will pass the second item in every array which is the (mobileNumber).
                intent.putExtra("order", mainObjectsArray.get(position)[0]);
                startActivity(intent);
            }
        });

        return rootView;

    }


    // Our adapter class
    class MyAdapter extends ArrayAdapter<String> {
        Context context;
        String rNames[];


        MyAdapter(Context c, String name[]) {
            super(c, R.layout.row, R.id.customerName, name);
            this.context = c;
            this.rNames = name;

        }

        public View getView(final int position, View convertView, ViewGroup parent) {
            LayoutInflater inflater = getLayoutInflater();
            View row = inflater.inflate(R.layout.row, parent, false);
            Button deleteButt = (Button) row.findViewById(R.id.deleteButton);
            deleteButt.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Toast.makeText(getActivity(), "delete me", Toast.LENGTH_SHORT).show();
                }
            });
            return row;
        }
        
    }


}

这是片段的 XML 代码

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <ListView
        android:id="@+id/myListView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

最后这是自定义单元格的 XML 代码

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:padding="16dp"
    android:descendantFocusability="blocksDescendants">


    <TextView
        android:id="@+id/customerName"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:text="custoemr name"
        android:textColor="#000"
        android:layout_margin="5dp"
        android:textSize="20sp"/>
    <Button
        android:id="@+id/deleteButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Delete"


    />

</LinearLayout>

请帮助我已经为此苦苦挣扎了几天！ 非常感谢。

Answer 1

    public View getView(final int position, View convertView, ViewGroup parent) ｛
       View row = super.getView(position, convertView, parent);
       Button deleteButt = (Button) row.findViewById(R.id.deleteButton); 
       deleteButt.setOnClickListener(new View.OnClickListener() { 
            @Override 
             public void onClick(View view) { 
                   Toast.makeText(getActivity(), "delete me", Toast.LENGTH_SHORT).show();
         } });
         return row; 
    }

还请注意，您的列表 rNames 是一个数组 []，它是固定大小的，不能删除单个项目。 如果要实现删除功能，则应使用 ArrayList。

更新：

public class HomeFragment extends Fragment {

// creating an empty array. This is an array of objects (array of arrays).
ArrayList<MainObjects> mainObjectsList = new ArrayList<>();
ListView myListView;

@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_home, null);

    // creaing a list view and connect it to the list view we created in the XML file
    // Note: we need to add (final) to be able to access them from inside the loop
    myListView = (ListView) rootView.findViewById(R.id.myListView);

    // Retrieving the data and filling the array with it
    ParseQuery<ParseObject> query = ParseQuery.getQuery("Orders");
    query.orderByDescending("updatedAt");
    query.findInBackground(new FindCallback<ParseObject>() {
        @Override
        public void done(List<ParseObject> objects, ParseException e) {
            if (e == null) {
                //Log.i("findInBackground", "Retrieved: " + objects.size() + "objects");
                if (objects.size() > 0) {
                    for (ParseObject object : objects) {
                        // Converting every object to an array of two items, title and body.
                        //String[] artical = {object.getString("TheSavedOrder"), object.getString("mobileNumber"), object.getString("Name")};
                        MainObjects article = new MainObjects(object.getString("TheSavedOrder"), object.getString("mobileNumber"), object.getString("Name");
                        // Adding the array to our main array so we will have an array of arrays
                        mainObjectsList.add(article);

                        //Log.i("This my family array: ", myFamily.toString());
                    }
                    // Applying our adapter
                    MyAdapter adapter = new MyAdapter(getActivity(), mainObjectsList);
                    myListView.setAdapter(adapter);
                }
            }
        }
    });

    // When clicking on an item in the list view
    myListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            //Log.i("The body is: ", mainObjectsList.get(position));
            Intent intent = new Intent(getContext(), TheBody.class);
            intent.putExtra("mobile", mainObjectsList.get(position).getMobileNumber());
            intent.putExtra("order", mainObjectsList.get(position).getSavedOrder());
            startActivity(intent);
        }
    });
    return rootView;
}

class MainObjects {
    String savedOrder = "", mobileNumber = "", name = "";

    public MainObjects(String savedOrder, String mobileNumber, String name) {
        this.savedOrder = savedOrder;
        this.mobileNumber = mobileNumber;
        this.name = name;
    }

    public String getSavedOrder() {
        return savedOrder;
    }

    public String getMobileNumber() {
        return mobileNumber;
    }

    public String getName() {
        return name;
    }
}

class MyAdapter extends ArrayAdapter<MainObjects> {
    Context context;
    LayoutInflater inflater;
    ArrayList<MainObjects> rNames;

    MyAdapter(Context c, ArrayList<MainObjects> name) {
        super(c, R.layout.row, R.id.customerName, name);
        this.context = c;
        this.rNames = name;
        inflater = getLayoutInflater();
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        View row = inflater.inflate(R.layout.row, parent, false);

        TextView nameTv = (TextView) row.findViewById(R.id.customerName);
        nameTv.setText(getItem(position).getName());

        Button deleteButt = (Button) row.findViewById(R.id.deleteButton);
        deleteButt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                int pos = (int)view.getTag();
                String msg = "Delete: " + pos + ". " + getItem(pos).getName() + " !!";
                Toast.makeText(context, msg, Toast.LENGTH_SHORT).show();
                rNames.remove(pos);
                notifyDataSetChanged();
                //
                // Codes to update permanent storage, e.g. files/server/db.
                //
            } });
        deleteButt.setTag(position);
        return row;
    }
}

}