Android Question (SOLVED) List in map I don't understand

yfleury · May 13, 2020

Hi all.
I create a list with some data.
After that I create a map and I put the list in. I log the map and I see the list and it's data. Fine

I clear the list and log again the map and the list inside the map is empty.

I need to keep data list in map even if I delete the list

B4X:

Sub Sub1
    list1.Add(1)
    list1.Add(2)
    list1.Add(3)
    list1.Add(4)

    map1.Put(1, list1)
    Log(map1) 'this show : (MyMap) {1=[1, 2, 3, 4]}
    list1.Clear
    Log(map1) 'this show : (MyMap) {1=[]}
End Sub

KMatle · May 13, 2020

The output is correct. You put ONE list in a map. In the next step you clear the list. It's the same object.

I assume you want to add different lists. So put a "Dim List1 as List" before it each time and initialize it. This will create different lists.

It's like to put ONE box in a shelf with some things in it. If you empty it, it's empty. You need several boxes, not just one.

Erel · May 13, 2020

Why is list1 a global variable? It should be a local variable.

yfleury · May 13, 2020

Erel said:
Why is list1 a global variable? It should be a local variable.

Because I need to add a list in map when I click on button
I make a small project

Erel · May 13, 2020

You must add a new List each time.

B4X:

Sub Button1_Click
    counter=counter+1
    map1.Put(1, list)
    Log(map1)
    list1.Clear 'not needed
    Log(map1)
Sub1
End Sub

Sub Sub1
     Dim list1 As List 'these two lines will create a new list.
   list1.Initialize
    list1.Add(1)
    list1.Add(2)
    list1.Add(3)
    list1.Add(4)
End Sub

yfleury · May 13, 2020

Erel said:

You must add a new List each time.

B4X:

Sub Button1_Click
    counter=counter+1
    map1.Put(1, list)
    Log(map1)
    list1.Clear 'not needed
    Log(map1)
Sub1
End Sub

Sub Sub1
     Dim list1 As List 'these two lines will create a new list.
   list1.Initialize
    list1.Add(1)
    list1.Add(2)
    list1.Add(3)
    list1.Add(4)
End Sub

Well, I need to complete my small project to be explain more what I need. I will post it this night.... I go to work

yfleury · May 13, 2020

I finnaly have time to done it

aeric · May 13, 2020

What is your expected output?

B4X:

Copying updated assets files (1)
*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
** Activity (main) Resume **
(MyMap) {1=[1, 2, 3, 4, 1]}
(MyMap) {1=[]}
(MyMap) {1=[1, 2, 3, 4, 2]}
(MyMap) {1=[]}
(MyMap) {1=[1, 2, 3, 4, 3]}
(MyMap) {1=[]}
(MyMap) {1=[1, 2, 3, 4]}
(MyMap) {1=[]}

yfleury · May 13, 2020

When I click GO I need to insert list in map and I can start a reset the list and add new items to list and by cliking GO add news items list to the map . This will appent few or more time.

yfleury · May 13, 2020

I see the light ?

Android Question (SOLVED) List in map I don't understand

yfleury

Active Member

KMatle

Expert

Erel

B4X founder

yfleury

Active Member

Attachments

Erel

B4X founder

yfleury

Active Member

yfleury

Active Member

Attachments

aeric

Expert

yfleury

Active Member

yfleury

Active Member

Attachments

Similar Threads

Android Question (SOLVED) List in map I don't understand

Active Member

Expert

B4X founder

Active Member

Attachments

B4X founder

Active Member

Active Member

Attachments

Expert

Active Member

Active Member

Attachments

Similar Threads

Privacy & Transparency

Privacy & Transparency