将数据从一个活动传递到另一个活动

Question

I am new at developing Android.I have a activity A that has a listview.When I clicked the item on listview,activity B is launched to view detail of selected item of listview.Then when I clicked the option menu item(Edit) on activity B ,activity C is launched to edit detail of selected item of listview.After editing the detail,I want to trasfer detail of item from activity C to activity A.Data of listview is hold arraylist on activity A. My question is how can I obtain (by which method) detail of item coming from activity C to activity A. Please help me to get rid of the problem. A(list)--->B(show)--->C(edit)--->A(list)

Answer 1

Do not transfer complex data from one activity to another, instead use like in web pages do. Passing something like querystrings and then retrieve the data based on the key submitted from one activity to another.

See code below: This is the First Activity calling the second activity and passing two variables.

var focus = new Intent(this, typeof(Focus));
                    Bundle newextra = new Bundle();
                    newextra.PutString("ID", ID.ToString());
                    newextra.PutString("Step", step.ToString());
                    focus.PutExtras(newextra);
                    StartActivity(focus);

Then at the next activity you can retrieve data as follow:

Bundle extras = Intent.Extras;
        var id = int.Parse(extras.GetString("ID"));
        var step = int.Parse(extras.GetString("Step"));

Then retrieve the data from local storage (database or something)