Question

我有一个DisplayStudentName.java文件，这是我的主要活动文件。有一个模型类用于获取和设置数据，还有一个MyCustomAdapter.java文件，它扩展了ArrayAdapter以实现listview功能。

单击该复选框，但未在arraylist中添加值（命名数据;键入String）。

DisplayStudentName.java

public class MyCustomAdapter extends ArrayAdapter {
public ArrayList<Student> personList=null;
private Context context=null;
private static LayoutInflater inflater=null;
private ArrayList<String> data=null;
private View vi;
ViewHolder holder=null;

public MyCustomAdapter(Context context, int resource, ArrayList<Student> personList) {
super(context, resource, personList);
this.context=context;
this.personList=personList;
}

private class ViewHolder{
TextView roll;
TextView name;
CheckBox check;
}


public View getView(int position, View convertView, ViewGroup parent){
Log.v("ConvertView", String.valueOf(position));

if(convertView==null){
    LayoutInflater vi = (LayoutInflater)context.getSystemService(
            Context.LAYOUT_INFLATER_SERVICE);
    convertView = vi.inflate(R.layout.list_item, null);

    holder=new ViewHolder();
    holder.roll=(TextView)convertView.findViewById(R.id.roll);
    holder.name=(TextView)convertView.findViewById(R.id.name);
    holder.check=(CheckBox)convertView.findViewById(R.id.checkBox);
    convertView.setTag(holder);

}
else{
    holder=(ViewHolder)convertView.getTag();
}


Student student=personList.get(position);
holder.roll.setText(student.getRollno());
holder.name.setText(student.getName());
holder.check.setTag(student);

holder.check.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        if (isChecked) {
            data.add(holder.check.getText().toString());
        } else {
            data.remove(holder.check.getText().toString());
        }
    }
});

return convertView;


}

MyCustomAdapter.java

public class Student {
String rollno;
String name;
Boolean checkbox;

public  Student(){

}
public Student(String rollno, String name, Boolean status){
super();
this.rollno=rollno;
this.name=name;
this.checkbox=status;
}

public String getRollno(){
return rollno;
}

public void setRollNo(String rollno){
this.rollno=rollno;
}

public String getName(){
return name;
}

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

public Boolean isCheckbox(){
return checkbox;
}

public void setCheckbox(boolean checkbox) {
this.checkbox= checkbox;
}

}

Student.java -Model class
```
MyGreatProtocol
```

请告诉我我的代码有什么问题？ }

Answer 1

每当您对数据集进行任何更改时，请致电notifyDataSetChanged()。

因此会是这样的：

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    if (isChecked) {
        data.add(holder.check.getText().toString());
    } else {
        data.remove(holder.check.getText().toString());
    }
    notifyDataSetChanged();
}

在列表视图中选中复选框时未在arraylist中添加的值。

1 个答案: