android-listview - Androidでリストビューを下にスクロールすると、トグルボタンの状態が変わりますか?

Question

i have placed a textview and a toggle button into a list view by using the following xml file and i have used an arrayadapter to set it on to my layout, my problem is when i scroll down in the list view by unchecking a few toggle buttons (which are all set to be checked by default), they go back to default state and few others change state. As i want to fetch the state of the toggle button in my later stages its very important to stick on to the state that ive assigned to the toggle button. Please help to resolve this problem. Here are my xml file and the java code i use to set it on to the adapter. thank you in prior...


xml file that is named listdecor is included here 


    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/lvlistdecor"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="#000000"
        android:orientation="horizontal"
        android:weightSum="2" >

        <TextView
            android:id="@+id/tvlistdecor"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1.5"
            android:ellipsize="marquee"
            android:singleLine="true"
            android:text="sample"
            android:textColor="#FFFFFF"
            android:textSize="24sp"
            android:typeface="sans" />

        <CheckBox
            android:id="@+id/cbusn_checked"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:layout_marginRight="6sp"
            android:layout_weight="0.5"
            android:checked="true"
            android:focusable="false"
            android:padding="10dp" />

    </LinearLayout>

Sir i は特定の変更を行い、リストビューにカスタム アダプターを含め、トグル ボタンの代わりに CheckBox に変更しました。しかし、リストビュー全体がエミュレーターに表示されなくなりました。編集した Java クラスと xml ファイルを含めました。変更を提案してください。ありがとうございます...変更された Java コードはここに含まれています

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE); // Setting the window to full screen Step 1
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN); // Setting the window to full screen Step 2

    setContentView(R.layout.attendance5);


    facid = (TextView) findViewById(R.id.tvfacid);
    facname = (TextView) findViewById(R.id.tvfacname);
    subjectchosen = (TextView) findViewById(R.id.tvsubject);
//  llattendlist = (LinearLayout)findViewById(R.id.llattendlist);


    String Uid = getIntent().getStringExtra("Uid");
    facid.setText(Uid);

    String Name = getIntent().getStringExtra("Name");
    facname.setText(Name);


    String Sub = getIntent().getStringExtra("Sub");
    subjectchosen.setText(Sub);



    Attendusn = getIntent().getExtras();
    if(Attendusn!=null)
    {
        AttendStud_usn = (ArrayList<String>)Attendusn.getStringArrayList("AttendStud_usn");
    }
    String AttendLen = String.valueOf(AttendStud_usn.size());
    //int flag = 0 ;
    //subjectchosen.setText(String.valueOf(AttendStud_usn));

    myListView = (ListView) findViewById(R.id.lvnames);
     // myListView.setAdapter(new ArrayAdapter<String>(this, R.layout.listdecoration,R.id.tvlistdecor, AttendStud_usn));
    //ArrayAdapter<String> MyAdapter= new ArrayAdapter<String>(this,R.layout.listdecoration, R.id.tvlistdecor,AttendStud_usn);
    //myListView.setAdapter(MyAdapter);
    myListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View item, int position,
                long id) {
            // TODO Auto-generated method stub
            Stud_usn usn= MyAdapter.getItem(position);
            usn.toggleChecked();
            Stud_usnViewHolder vh_usn= (Stud_usnViewHolder) item.getTag();
            vh_usn.getCheckBox().setChecked(usn.isChecked());
        }
    });

    MyAdapter = new Stud_Adapter(this,AttendStud_usn);
    myListView.setAdapter(MyAdapter);

}
private static class Stud_usn{
    private String usn_no="";
    private boolean checked=true;
    public Stud_usn(String usn_no){
        this.usn_no = usn_no;
    }
    public String getUsn(){
        return usn_no;
    }
    public void setChecked(boolean checked){
        this.checked=checked;
    }
    public Object isChecked() {
        // TODO Auto-generated method stub
        return checked;
    }
    public String toString(){
        return usn_no;
    }
    public void toggleChecked() {
        // TODO Auto-generated method stub
        checked = !checked;
    }
}
private static class Stud_usnViewHolder{
    private CheckBox checkbox;
    private TextView textview;

    public Stud_usnViewHolder(TextView textview, CheckBox checkbox){
        this.checkbox=checkbox;
        this.textview=textview;
    }
    public CheckBox getCheckBox() {
        // TODO Auto-generated method stub
        return checkbox;

    }
    public TextView getTextView(){
        return textview;
    }
}

private static class Stud_Adapter extends ArrayAdapter<Stud_usn>{

    public LayoutInflater inflater;
    public Stud_Adapter(Context context, List<String> attendStud_usn) {
        super(context,R.layout.listdecoration,R.id.tvlistdecor);
        // TODO Auto-generated constructor stub
        inflater = LayoutInflater.from(context);
    }

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

        Stud_usn usn = (Stud_usn) this.getItem(position);

        CheckBox checkbox;
        TextView textview;

        if(convertView  == null){
            convertView = inflater.inflate(R.layout.listdecoration,null);
            textview = (TextView) convertView.findViewById(R.id.tvlistdecor);
            checkbox = (CheckBox) convertView.findViewById(R.id.cbusn_checked);


        }

        return convertView;

    }

}

}