Question

我制作了一个应用程序，其中包含设备中所有已安装应用程序的列表，我在recyclerview中添加了一个复选框，以便在列表中选择一个应用程序（我将使用此应用程序作为应用程序的基础阻滞剂）。问题是当向上/向下滚动时，复选框状态总是会改变。恩。我检查了facebook然后我向下滚动，当我向上滚动时，facebook未经检查，有时会检查随机应用。

这是我的代码：

ApkInfoextractor：

public class ApkInfoExtractor {

    Context context1;

    public ApkInfoExtractor(Context context2){

        context1 = context2;
    }

    public List<String> GetAllInstalledApkInfo(){

        List<String> ApkPackageName = new ArrayList<>();

        Intent intent = new Intent(Intent.ACTION_MAIN,null);
        intent.addCategory(Intent.CATEGORY_LAUNCHER);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED );

        //Information that is returned from resolving an intent against an IntentFilter
        List<ResolveInfo> resolveInfoList = context1.getPackageManager().queryIntentActivities(intent,0);

        for(ResolveInfo resolveInfo : resolveInfoList){
            ActivityInfo activityInfo = resolveInfo.activityInfo;

            if(!isSystemPackage(resolveInfo)){

                ApkPackageName.add(activityInfo.applicationInfo.packageName);
            }
        }
        return ApkPackageName;
    }

    public boolean isSystemPackage(ResolveInfo resolveInfo){
        return ((resolveInfo.activityInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0);
    }

    public Drawable getAppIconByPackageName(String ApkTempPackageName){
        Drawable drawable;

        try{
            drawable = context1.getPackageManager().getApplicationIcon(ApkTempPackageName);
        }
        catch (PackageManager.NameNotFoundException e){

            e.printStackTrace();
            drawable = ContextCompat.getDrawable(context1, R.mipmap.ic_launcher);
        }
        return drawable;
    }

    public String GetAppName(String ApkPackageName){

        String Name = "";
        ApplicationInfo applicationInfo;
        PackageManager packageManager = context1.getPackageManager();

        try {

            applicationInfo = packageManager.getApplicationInfo(ApkPackageName, 0);

            if(applicationInfo!=null){
                Name = (String)packageManager.getApplicationLabel(applicationInfo);
            }

        }catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        return Name;
    }
}

AppsAdapter：

public class AppsAdapter extends RecyclerView.Adapter<AppsAdapter.ViewHolder>{

    private Context context1;
    private List<String> stringList;

    public AppsAdapter(Context context, List<String> list){
        context1 = context;
        stringList = list;
    }

    //viewholder initialized
    @Override
    public AppsAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType){

        View view2 = LayoutInflater.from(context1).inflate(R.layout.cardview_layout,parent,false);
        ViewHolder viewHolder = new ViewHolder(view2);
        return viewHolder;
    }

    private SparseBooleanArray sba = new SparseBooleanArray();

    //DATA IS BOUND TO VIEWS
    @Override
    public void onBindViewHolder(ViewHolder viewHolder,final int position){

        viewHolder.setIsRecyclable(false);
        ApkInfoExtractor apkInfoExtractor = new ApkInfoExtractor(context1);
            final String ApplicationPackageName = (String) stringList.get(position);

        //calling apps name and icon
        String ApplicationLabelName = apkInfoExtractor.GetAppName(ApplicationPackageName);
        Drawable drawable = apkInfoExtractor.getAppIconByPackageName(ApplicationPackageName);

        //setting app name and icon for every card
        viewHolder.textView_App_Name.setText(ApplicationLabelName);
        viewHolder.imageView.setImageDrawable(drawable);

        //saving states of the checkbox
        viewHolder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                sba.put(position, !sba.get(position));
                notifyDataSetChanged();
            }
        });
        viewHolder.checkBox.setChecked(sba.get(position));

    }

    //viewholder
    public class ViewHolder extends RecyclerView.ViewHolder{

        public CardView cardView;
        public ImageView imageView;
        public TextView textView_App_Name;
        public CheckBox checkBox;

        public ViewHolder (View view){

            super(view);
            checkBox = (CheckBox) view.findViewById(R.id.chckbox);
            cardView = (CardView) view.findViewById(R.id.card_view);
            imageView = (ImageView) view.findViewById(R.id.imageview);
            textView_App_Name = (TextView) view.findViewById(R.id.Apk_Name);
            //textView_App_Package_Name = (TextView) view.findViewById(R.id.Apk_Package_Name);

        }
    }

    @Override
    public int getItemCount(){
        return stringList.size();
    }
}

我尝试过谷歌的许多解决方案，但这些解决方案都不适用于我。因此，详细的答案将会有所帮助（非常感谢示例代码或其他参考。）

Answer 1

您可以使用Set

代替SparseBooleanArray

    HashSet<Integer> selection = new HashSet<>();

在onBind方法中使用以下，也使用标记而不是使位置最终

//saving states of the checkbox
        viewHolder.itemView.setTag(position);
        viewHolder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int pos = (int) v.getTag();
                if (selection.contains(pos))
                    selection.remove(pos);
                else 
                    selection.add(pos);
                notifyDataSetChanged();
            }
        });
        viewHolder.checkBox.setChecked(selection.contains(position));

Answer 2

过去2年我也遇到过这个问题。但是我使用HashMap克服了这些问题。将布尔值保存在Hash Map上单击的项目中。从HashMap

获取onBindViewHolder

您可以参考我的ConsistantRecylerAdapter

Answer 3

将您的观看者更改为

         public ViewHolder (View view){

            super(view);
            checkBox = (CheckBox) view.findViewById(R.id.chckbox);
            cardView = (CardView) view.findViewById(R.id.card_view);
            imageView = (ImageView) view.findViewById(R.id.imageview);
            textView_App_Name = (TextView) view.findViewById(R.id.Apk_Name);
            //textView_App_Package_Name = (TextView) view.findViewById(R.id.Apk_Package_Name);
           this.setIsRecyclable(false);
        }

声明：

 this.setIsRecyclable(false);

这只是解决方法，这可能会阻止回收者查看不重用单元格

Answer 4

我遇到了完全相同的问题并在经过大量研究后得到了解决。原因是每次滚动列表项时都处于循环视图中列表项被回收（再次创建）因此丢失其实例，像textbox或edittext这样的视图不支持其数据。

您可以尝试按照以下方法解决此问题：

单击复选框保存模型类中的值，然后在onCreate中检查JSON模型类中的值并分配给复选框

onCreate：

if(model.isChecked)) {
    checkbox.setChecked(true);

}else{
checkbox.setChecked(false);

}

然后点击复选框时点击：

checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked){
       model.setIsChecked(isChecked);
    }

我相信这会解决你的问题。

应用程序列表recyclerview复选框更改状态

4 个答案: