使用Listview中的复选框获取所选项目

Question

我正在创建一个Android应用程序,我有一个ListView,显示我的手机中安装的所有应用程序.

我的ListView是自定义的,它包含一个Icon,TextView和CheckBox,使用的图标是显示应用程序的图标,TextView是显示应用程序的名称,使用CheckBox是确定哪个项目在我选择的ListView.

当我单击应用程序中的按钮时,如何确定在ListView行中选择的CheckBox是什么？我是Android的新手,所以我不知道我应该做什么方法.

这是我的代码:

public class AppInfo {
    public Drawable icon;
    public String applicationName;

    public AppInfo(){
        super();
    }

    public AppInfo(Drawable icon, String applicationName){
        super();
        this.icon = icon;
        this.applicationName = applicationName;
    }


}

---

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import android.app.Activity;
import android.widget.CheckBox;

public class AppInfoAdapter extends ArrayAdapter<AppInfo> {

    Context context;
    int layoutResourceId;
    AppInfo  data[] = null;

    public AppInfoAdapter(Context context, int layoutResourceId, AppInfo[] data){
        super(context, layoutResourceId,data);
        this.layoutResourceId = layoutResourceId;
        this.context = context;
        this.data = data;
    }

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

        View row = convertView;
        AppInfoHolder holder= null;

        if (row == null){

            LayoutInflater inflater = ((Activity)context).getLayoutInflater();
            row = inflater.inflate(layoutResourceId, parent, false);

            holder = new AppInfoHolder();

            holder.imgIcon = (ImageView) row.findViewById(R.id.imgPackageIcon);
            holder.txtTitle = (TextView) row.findViewById(R.id.txtApplicationName);
            holder.chkSelect = (CheckBox) row.findViewById(R.id.chkSelect);

            row.setTag(holder);

        }
        else{
            holder = (AppInfoHolder)row.getTag();
        }


        AppInfo appinfo = data[position];
        holder.txtTitle.setText(appinfo.applicationName);
        holder.imgIcon.setImageDrawable(appinfo.icon);
        holder.chkSelect.setChecked(true);

        return row;

    }



}

---

import android.widget.ImageView;
import android.widget.TextView;
import android.widget.CheckBox;

public class AppInfoHolder {

    ImageView imgIcon;
    TextView txtTitle;
    CheckBox chkSelect;
}

---

import android.app.Activity;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter; 
import android.widget.ListView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;
import android.content.pm.PackageInfo;

public class CacheActivity extends Activity {

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


            final ListView listApplication = (ListView)findViewById(R.id.listApplication);

            ApplicationInfo applicationInfo = getApplicationInfo();
            PackageManager pm = getPackageManager();
            List<PackageInfo> pInfo = new ArrayList<PackageInfo>();
            pInfo.addAll(pm.getInstalledPackages(0));
            AppInfo app_info[] = new AppInfo[pInfo.size()];

            int counter = 0;
            for(PackageInfo item: pInfo){
                try{

                    applicationInfo = pm.getApplicationInfo(item.packageName, 1);

                    app_info[counter] = new AppInfo(pm.getApplicationIcon(applicationInfo), 
                            String.valueOf(pm.getApplicationLabel(applicationInfo)));

                    System.out.println(counter);

                }
                catch(Exception e){
                     System.out.println(e.getMessage());
                }

                counter++;
            }

            AppInfoAdapter adapter = new AppInfoAdapter(this, R.layout.listview_item_row, app_info);
            listApplication.setAdapter(adapter);

        }


}

Answer 1

假设您想要获取行的项目,只需单击按钮即可选中其复选框.假设基于您的标题"单击按钮时使用列表视图中的复选框获取所选项目".

试试下面的内容.仅进行如下更改.其余部分保持不变.

@主题的解释和讨论

https://groups.google.com/forum/?fromgroups#!topic/android-developers/No0LrgJ6q2M

MainActivity.java

public class MainActivity extends Activity {
     AppInfoAdapter adapter ;
     AppInfo app_info[] ;
        @Override
        protected void onCreate(Bundle savedInstanceState){
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);


            final ListView listApplication = (ListView)findViewById(R.id.listApplication);
            Button b= (Button) findViewById(R.id.button1);
            b.setOnClickListener(new OnClickListener()
            {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub

                    StringBuilder result = new StringBuilder();
                    for(int i=0;i<adapter.mCheckStates.size();i++)
                    {
                        if(adapter.mCheckStates.get(i)==true)
                        {

                                           result.append(app_info[i].applicationName);
                            result.append("\n");
                        }

                    }
                    Toast.makeText(MainActivity.this, result, 1000).show();
                }

            });

            ApplicationInfo applicationInfo = getApplicationInfo();
            PackageManager pm = getPackageManager();
            List<PackageInfo> pInfo = new ArrayList<PackageInfo>();
            pInfo.addAll(pm.getInstalledPackages(0));
            app_info = new AppInfo[pInfo.size()];

            int counter = 0;
            for(PackageInfo item: pInfo){
                try{

                    applicationInfo = pm.getApplicationInfo(item.packageName, 1);

                    app_info[counter] = new AppInfo(pm.getApplicationIcon(applicationInfo), 
                            String.valueOf(pm.getApplicationLabel(applicationInfo)));

                    System.out.println(counter);

                }
                catch(Exception e){
                     System.out.println(e.getMessage());
                }

                counter++;
            }

           adapter = new AppInfoAdapter(this, R.layout.listview_item_row, app_info);
            listApplication.setAdapter(adapter);

        }
}

activity_main.xml ListView,按钮位于按钮处

<RelativeLayout 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: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=".MainActivity" >

    <ListView
        android:layout_width="fill_parent"
        android:id="@+id/listApplication"
        android:layout_height="fill_parent"
        android:layout_above="@+id/button1"
        android:text="@string/hello_world" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:text="Button" />

</RelativeLayout>

AppInfoAdapter

public class AppInfoAdapter extends ArrayAdapter<AppInfo> implements CompoundButton.OnCheckedChangeListener
{  SparseBooleanArray mCheckStates; 

    Context context;
    int layoutResourceId;
    AppInfo  data[] = null;

    public AppInfoAdapter(Context context, int layoutResourceId, AppInfo[] data){
        super(context, layoutResourceId,data);
        this.layoutResourceId = layoutResourceId;
        this.context = context;
        this.data = data;
        mCheckStates = new SparseBooleanArray(data.length);
    }

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

        View row = convertView;
        AppInfoHolder holder= null;

        if (row == null){

            LayoutInflater inflater = ((Activity)context).getLayoutInflater();
            row = inflater.inflate(layoutResourceId, parent, false);

            holder = new AppInfoHolder();

            holder.imgIcon = (ImageView) row.findViewById(R.id.imageView1);
            holder.txtTitle = (TextView) row.findViewById(R.id.textView1);
            holder.chkSelect = (CheckBox) row.findViewById(R.id.checkBox1);

            row.setTag(holder);

        }
        else{
            holder = (AppInfoHolder)row.getTag();
        }


        AppInfo appinfo = data[position];
        holder.txtTitle.setText(appinfo.applicationName);
        holder.imgIcon.setImageDrawable(appinfo.icon);
       // holder.chkSelect.setChecked(true);
        holder.chkSelect.setTag(position);
        holder.chkSelect.setChecked(mCheckStates.get(position, false));
        holder.chkSelect.setOnCheckedChangeListener(this);
        return row;

    }
    public boolean isChecked(int position) {
        return mCheckStates.get(position, false);
    }

    public void setChecked(int position, boolean isChecked) {
        mCheckStates.put(position, isChecked);

    }

    public void toggle(int position) {
        setChecked(position, !isChecked(position));

    }
@Override
public void onCheckedChanged(CompoundButton buttonView,
        boolean isChecked) {

     mCheckStates.put((Integer) buttonView.getTag(), isChecked);    

}
static class AppInfoHolder
{
    ImageView imgIcon;
    TextView txtTitle;
    CheckBox chkSelect;

}
}

这是快照

Answer 2

这是一个简化,但非常简单......您需要将可聚焦标志添加到复选框,如前所述.您还需要添加可点击标记,如下所示:

android:focusable="false"
android:clickable="false"

比你在ListView(ListFragment在我的情况下)onListItemClick事件中控制复选框状态.

这个样本onListItemClick方法:

public void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
//Get related checkbox and change flag status..
CheckBox cb = (CheckBox)v.findViewById(R.id.rowDone);
cb.setChecked(!cb.isChecked());
Toast.makeText(getActivity(), "Click item", Toast.LENGTH_SHORT).show();
}

Answer 3

您必须将OnItemClickListener添加到列表视图以确定单击了哪个项目,然后找到该复选框.

mListView.setOnItemClickListener(new OnItemClickListener()
{
    @Override
    public void onItemClick(AdapterView<?> parent, View v, int position, long id)
    {
        CheckBox cb = (CheckBox) v.findViewById(R.id.checkbox_id);
    }
});