Android how to sort list of objects in list view by column

I bind list of class objects using adapters in android list view, the list view have 3 column headers(3 header buttons), each header have click event, now i want to sort list view by column means when ever i click on first header column, the data sorted with respect to first column, i click s开发者_如何学JAVAecond header sorted the data with respect to second column.How can i do this one.

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Loads of pseudo code ahead, you've been warned.

Say you have a class Foo

class Foo{

private int param1;
private float param2;
private String param3;
}

Now make 3 Comparators, one for each member you want to sort with. Preferably make it a static member of the same class.

class Foo
{
  public static Comparator PARAM1_COMPARATOR = <defination>;
  public static Comparator PARAM2_COMPARATOR = <defination>;
  public static Comparator PARAM3_COMPARATOR = <defination>;
}

In your activity, have this function refreshList() (or something of that sort ) which is called when the sorting order is to be changed.

void refreshList()
{
  List<Foo> list = //say this is your list

  //Pro tip: User a switch case instead.

  if(Sort_by_param1)
   Collections.sort(list, Foo.PARAM1_COMPARATOR);
  if(Sort_by_param2)
   Collections.sort(list, Foo.PARAM2_COMPARATOR);
  if(Sort_by_param3)
   Collections.sort(list, Foo.PARAM3_COMPARATOR);

  adapter.notifyDatasetChanged() or call setAdapter again with the new list.
}

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Follow this code to sort any ArrayList

  Collections.sort(empList, new Comparator<Employee>(){
  public int compare(Employee emp1, Employee emp2) {
    return emp1.getFirstName().compareToIgnoreCase(emp2.getFirstName());
  }
});