如何在列表视图中添加开关以及如何在新活动中打开和关闭状态

Question

我想在下一个活动中关闭所有用户，但我无法做到。 listview 中的每个项目都有开关，但我无法存储或获取每个项目的状态。

我想为所有项目添加开关，我想保存开关的所有状态。我想在新活动中访问所有关闭的项目。

这是 adminhome.java 文件，它显示了此活动页面上的所有列表视图项：

package com.example.nilesh.loginpa;

import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Switch;
import android.widget.TextView;

import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import java.util.ArrayList;
import java.util.List;

public class Adminhome extends AppCompatActivity {
    FirebaseAuth firebaseauth;
    DatabaseReference mref;
    Button btn;

    //private String uname;

    //private ArrayList<String> ulist = new ArrayList<>();

    List<UserProfile> userlist;
    ListView allusers;
    Switch switch1;

    //private ArrayAdapter<String> arrayAdapter;

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

        //firebaseauth = FirebaseAuth.getInstance();
        mref = FirebaseDatabase.getInstance().getReference("users");
        btn = (Button) findViewById(R.id.btnsub);
        allusers = (ListView) findViewById(R.id.lvusers);
        userlist = new ArrayList<>();
        //arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,ulist);
        //allusers.setAdapter(arrayAdapter);
    }

    @Override
    protected void onStart() {
        super.onStart();

        mref.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                userlist.clear();
                for (DataSnapshot userprofileSnapshot : dataSnapshot.getChildren()){
                    UserProfile userProfile = userprofileSnapshot.getValue(UserProfile.class);
                    userlist.add(userProfile);
                }

                Userslist adapter = new Userslist(Adminhome.this,userlist);
                allusers.setAdapter(adapter);
            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {
            }
        });
    }
}

这是 UserList.java 文件，用于保存列表视图中的项目：

package com.example.nilesh.loginpa;

import android.app.Activity;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.CompoundButton;
import android.widget.Switch;
import android.widget.TextView;

import java.util.List;

public class Userslist extends ArrayAdapter <UserProfile> {
    private Activity context;
    private List<UserProfile> userlist;

    public Userslist(Activity context,List<UserProfile> userlist){
        super(context,R.layout.list_layout,userlist);
        this.context =context;
        this.userlist = userlist;
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        LayoutInflater inflater = context.getLayoutInflater();

        View listViewItem = inflater.inflate(R.layout.list_layout, null, true);

        TextView textViewName = (TextView) listViewItem.findViewById(R.id.textViewName);
        TextView textViewemail = (TextView) listViewItem.findViewById(R.id.textViewemail);
        Switch switch1 = (Switch) listViewItem.findViewById(R.id.switch1);

        UserProfile userProfile = userlist.get(position);

        textViewName.setText(userProfile.getName());
        textViewemail.setText(userProfile.getEmail());

        return listViewItem;
    }


}

这是 UserProfile.java 代码，用于从 firebase 访问所有用户详细信息：

package com.example.nilesh.loginpa;

public class UserProfile {
    public String name;
    public String email;
    public String age;
    public UserProfile(){
    }

    public UserProfile(String name, String email, String age) {
        this.name = name;
        this.email = email;
        this.age = age;
    }

    public String getName() {
        return name;
    }

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

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }

    @Override

    public String toString(){
        return this.name + ":" + this.age;
    }
}

Answer 1

请看这个例子。您需要具有列表项所需外观的 XML 布局（在此示例中，列表项由一个 textview 和一个切换按钮组成）：

private class ShopItemListAdapter extends BaseAdapter {

        private List<ShopItem> shopItems;

        private ShopItemListAdapter(List<ShopItem> shopItems) {
            this.shopItems = shopItems;
        }

        @Override
        public int getCount() {
            return shopItems.size();
        }

        @Override
        public Object getItem(int position) {
            return shopItems.get(position);
        }

        @Override
        public long getItemId(int position) {
            return shopItems.get(position).getId();
        }

        @Override
        public View getView(final int position, View convertView, ViewGroup parent) {
            ShopItem shopItem = shopItems.get(position);
            if (convertView == null) {
                LayoutInflater layoutInflater = getLayoutInflater();
                convertView = layoutInflater.inflate(R.layout.shopitem, null);
                TextView textView = convertView.findViewById(R.id.shopItemText);
                ToggleButton toggleButton = convertView.findViewById(R.id.shopItemBought);

                ViewHolder viewHolder = new ViewHolder(toggleButton, textView);

                convertView.setTag(viewHolder);
            }
            ViewHolder viewHolder = (ViewHolder) convertView.getTag();
            // click listener must be set always no matter of convertView is or is not null
            // otherwise recycle view behaves strangely to checked states of toggle buttons
            viewHolder.shopItemBought.setOnClickListener(new ToggleBoughtListener(shopItem));
            viewHolder.shopItemBought.setChecked(shopItem.isBought());
            viewHolder.shopItemName.setText(shopItem.getName());
            return convertView;
        }

        private class ViewHolder {
            ToggleButton shopItemBought;
            TextView shopItemName;

            ViewHolder(ToggleButton shopItemBought, TextView shopItemName) {
                this.shopItemBought = shopItemBought;
                this.shopItemName = shopItemName;
            }
        }
        private class ToggleBoughtListener implements View.OnClickListener {

            final ShopItem shopItem;

            private ToggleBoughtListener(ShopItem shopItem) {
                this.shopItem = shopItem;
            }

            @Override
            public void onClick(View v) {
                shopItem.setBought(!shopItem.isBought());
                repository.update(shopItem);
            }
        }
    }