Question

我从Web服务获取数据并加载到列表视图。哪个工作正常。但是当我点击一个特定的列表项时，我需要将该记录的ID（Id应该来自数据库）传递给另一个活动。这是我填充数组的代码

public String[] getNames(String response){
    String[] friends = null;
    try {
        JSONObject json = new JSONObject(response);
        String values = json.getString("friends");
        JSONArray jsonArray = new JSONArray(values);
        friends = new String[jsonArray.length()];
        //Bundle b = new Bundle();
        for (int i = 0; i < jsonArray.length(); i++) {

            friends[i] =  jsonArray.getJSONObject(i).getString("fname")+ " " + jsonArray.getJSONObject(i).getString("lname") ;
            friends[i+1] = jsonArray.getJSONObject(i).getString("id");
            //i++;  
            //friends[i]= jsonArray.getJSONObject(i).getString("id");
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return friends;
}

这是我试图获取名称和ID的代码

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);
    // Get the item that was clicked
    Object o = this.getListAdapter().getItem(position);
    String name = o.toString();
    Object x = this.getListAdapter().getItem(position+1);
    String userid= x.toString();
    Toast.makeText(this, "You selected: " + name +"The Id: "+userid, Toast.LENGTH_LONG)
            .show();
}

这是我的列表视图的xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:background="#ffffff"
>
<ImageView
android:id="@+id/icon"
android:padding="2dip"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/man"
/>
<TextView
android:id="@+id/txtName"
android:layout_width="210px"
android:layout_height="60px"
    android:padding="4dp"
    android:textSize="12sp" 
    android:textColor="#000000" 
    android:background="#ffffff"
/>

</LinearLayout>

这就是我填充列表视图的方式

public void setTheList(String response){
        String friends[] = getNames(response);
        ListView lv = getListView();
        lv.setTextFilterEnabled(true);
        if(adapter==null){
            LayoutInflater inflater = getLayoutInflater();
            ViewGroup header = (ViewGroup)inflater.inflate(R.layout.header, lv, false);
            lv.addHeaderView(header, null, false);
        }

        adapter = new MyArrayAdapter(this, friends);
        this.setListAdapter(adapter);

    }

}

这是我的适配器。我是从here

得到的

package virtualpathum.web;

import android.app.Activity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.TextView;

public class MyArrayAdapter extends ArrayAdapter<String> {
    private final Activity context;
    private final String[] names;

    public MyArrayAdapter(Activity context, String[] names) {
        super(context, R.layout.friend, names);
        this.context = context;
        this.names = names;
    }

    // static to save the reference to the outer class and to avoid access to
    // any members of the containing class
    static class ViewHolder {
        public ImageView imageView;
        public TextView textView;
        public ImageButton ibConfirm;
        public ImageButton ibNotNow;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // ViewHolder will buffer the assess to the individual fields of the row
        // layout

        ViewHolder holder;
        // Recycle existing view if passed as parameter
        // This will save memory and time on Android
        // This only works if the base layout for all classes are the same
        View rowView = convertView;
        if (rowView == null) {
            LayoutInflater inflater = context.getLayoutInflater();
            rowView = inflater.inflate(R.layout.friend, null, true);
            holder = new ViewHolder();
            holder.textView = (TextView) rowView.findViewById(R.id.txtName);
            holder.imageView = (ImageView) rowView.findViewById(R.id.icon);
            //holder.ibConfirm = (ImageButton) rowView.findViewById(R.id.ibNotNow);
            //holder.ibNotNow= (ImageButton) rowView.findViewById(R.id.ibNotNow);
            rowView.setTag(holder);
        } else {
            holder = (ViewHolder) rowView.getTag();
        }

        holder.textView.setText(names[position]);
        // Change the icon for Windows and iPhone
        String s = names[position];
        holder.imageView.setImageResource(R.drawable.man);

        return rowView;
    }
}

如果您对此有所了解，真的很感激谢谢巴吞

Answer 1

而是getnames返回String []创建一个表示一个人的类以及一个id并返回ArrayList

class Person {
   String name;
   int id;
   public Person(int id, String name){
   //Implement
   }
   //Implement getters and setters      
}

//Consider renaming to getPersons
ArrayList<Person> person = getNames();

getNames(String inputString)
{
   ...
   ArrayList<Person> persons = new ArrayList...
   persons.add(new Person("Brother",2)
   persons.add(new Person("Jonas",1)
   return persons;
}

ArrayAdapter<Person> arrayadapter = new YourArrayAdapter<Person>();
arrayadapter.addAll(getNames(inputString);


In you arrayadapter you override the getItemId
@Overide
getItemId(int position)
{
   return getItem(position).getItemId();
}

（我假设您正在使用ArrayAdapter或类似的东西）

然后在你的arrayadaper中相应地实现getId和getItem

Answer 2

非常感谢所有给予的支持。我使用@Richard提供的方法@ rafael-t的Tag概念。谢谢@ yashwanth-kumar的解释。以下是我原始代码的修改

public ArrayList<Object> getNames(String response){
        ArrayList<Object>  arrList = null;
        try {
            JSONObject json = new JSONObject(response);
            String values = json.getString("friends");
            JSONArray jsonArray = new JSONArray(values);
            arrList = new ArrayList<Object>();
            for (int i = 0; i < jsonArray.length(); i++) {  
                arrList.add(new User(jsonArray.getJSONObject(i).getString("id"),jsonArray.getJSONObject(i).getString("fname"),jsonArray.getJSONObject(i).getString("lname"),jsonArray.getJSONObject(i).getString("email")));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return arrList;
    }

这是我的getNames方法我将所有值添加到User Object。感谢@Richard。

以下是此次更改的自定义适配器

package virtualpathum.web;

import java.util.ArrayList;
import java.util.Iterator;

import android.app.Activity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.TextView;

public class MyArrayAdapter extends ArrayAdapter<ArrayList<Object>> {
    private final Activity context;
    private final ArrayList names;

    @SuppressWarnings("unchecked")
    public MyArrayAdapter(Activity context, ArrayList names) {
        super(context, R.layout.friend, names);
        this.context = context;
        this.names = names;
    }

    // static to save the reference to the outer class and to avoid access to
    // any members of the containing class
    static class ViewHolder {
        public ImageView imageView;
        public TextView textView;
        public ImageButton ibConfirm;
        public ImageButton ibNotNow;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // ViewHolder will buffer the assess to the individual fields of the row
        // layout

        ViewHolder holder;
        // Recycle existing view if passed as parameter
        // This will save memory and time on Android
        // This only works if the base layout for all classes are the same
        View rowView = convertView;
        if (rowView == null) {
            LayoutInflater inflater = context.getLayoutInflater();
            rowView = inflater.inflate(R.layout.friend, null, true);
            holder = new ViewHolder();
            holder.textView = (TextView) rowView.findViewById(R.id.txtName);
            holder.imageView = (ImageView) rowView.findViewById(R.id.icon);
            //holder.ibConfirm = (ImageButton) rowView.findViewById(R.id.ibNotNow);
            //holder.ibNotNow= (ImageButton) rowView.findViewById(R.id.ibNotNow);
            rowView.setTag(holder);
        } else {
            holder = (ViewHolder) rowView.getTag();
        }
        String [] frndNames = new String[names.size()];
        int count = 0;
        for (@SuppressWarnings("rawtypes")
        Iterator iterator = names.iterator(); iterator.hasNext();) {
            User user = (User) iterator.next();
            frndNames[count] = user.getFirstname()+" "+user.getLastname();
            count++;
        }
        String [] frndIds = new String[names.size()];
        int idCount = 0;
        for (@SuppressWarnings("rawtypes")
        Iterator iterator = names.iterator(); iterator.hasNext();) {
            User user = (User) iterator.next();
            frndIds[idCount] = user.getUserid();
            idCount++;
        }
        holder.textView.setText(frndNames[position]);
        holder.textView.setTag(frndIds[position]);
        holder.imageView.setImageResource(R.drawable.man);

        return rowView;
    }
}

这是单击侦听器

@Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);
        // Get the item that was clicked
        String userid = (String) v.findViewById(R.id.txtName).getTag();
        Toast.makeText(this, "Selected user ID = "+userid , Toast.LENGTH_LONG)
                .show();
    }

我仍然觉得这可以进一步优化以获得更好的性能，但现在对我来说已经绰绰有余了。再次谢谢你们。

Answer 3

在长按事件中，您有一个位置参数。无论您在何处存储数据，都可以使用此参数获取数据。如需进一步的帮助，您可能应该添加一些有关您使用的适配器类型的信息。

Answer 4

据我所知，你没有问题可以恢复身份。但是，您可以为任何视图提供标记（因此您可以将ID作为Tag传递给LinearLayout）。然后，如果您有自己的身份证，就可以开始新的活动：

Intent intent = new Intent(getContext(), YOUR_ACTIVITY_YOU_WANNA_START.class);
intent.putExtra("ID", userid);
startActivity(0, intent);

在接收活动（在本例中为YOUR_ACTIVITY_YOU_WANNA_START.class）中，您可以在onCreate（）中调用

Intent intent = getIntent();
String userId = intent.getExtra("ID" , "DEFAULT");

Answer 5

好的，这就是你要做的，在你的持有者类中添加一个新成员，让我们假设你的id数据类型是字符串。然后添加

public String mId;

持有人。并在从getView返回之前使用视图的相关id填充它。

holder.mId = Id_which_you_need;

在onItemClickListener中

，使用它来获取标记。

holder = (ViewHolder) v.getTag();

并获取Id，因为我们假设它是一个字符串。

id = holder.mId;

id就是你所需要的。这就是你所需要的，还有其他方法，因为你使用的是标签，我认为这会更好。

将数据加载到具有记录ID的android列表视图，并传递确切的记录ID onListItemClick

5 个答案: