Android Question How to update label.Text from an array

DickD · Jan 19, 2017

I'm trying to update text of a label in a layout created with the Designer. I need to do this in code with an array. I can do this with a simple variable but not with an array. I tried the following without success. It doesn't generate any errors but the text never displays. I have done this before in a layout generated in code but not with a Designer layout.

B4X:

Sub Globals
Dim ThisField(10) as Label
...
' Sports is the name of the label in the layout
Activity.LoadLayout("MyLayout")
ThisField(1).Initialize("Sports")
ThisField(1).Text = "Baseball"

Erel · Jan 20, 2017

You should never initialize views added with the designer.

B4X:

ThisField = Array As Label(Label1, Label2, ...)
...
ThisField(0).Text = "abc"

DickD · Jan 20, 2017

Erel said:
You should never initialize views added with the designer.

B4X:

Dim ThisField() as Label ThisField = Array As Label(Sports, Politics, ...) ... Line = "abc" ThisField(0).Text = Line

This didn't work. Although it compiled properly I got the runtime error "Object should first be initialized (Label)". I tried putting the array elements in quotes since they are strings but that caused a "Types do not match" error.

DonManfred · Jan 20, 2017

1. Add the labels with the designer.
2. ADD REFERNCES to ALL OBJECTS IN THE LAYOUT.

do this for all labels...
2. In your code you now add all the items to the array. See post #2

DickD said:
I tried putting the array elements in quotes since they are strings

NO! The problem is here.

B4X:

    Private Label1 As Label

Label1 is NOT A STRING.
Add Label1 to the array together with the other 9 Labelnames.

DickD · Jan 20, 2017

DonManfred said:
1. Add the labels with the designer.
2. ADD REFERNCES to ALL OBJECTS IN THE LAYOUT.

do this for all labels...
2. In your code you now add all the items to the array. See post #2

NO! The problem is here.

B4X:

Private Label1 As Label

Label1 is NOT A STRING.
Add Label1 to the array together with the other 9 Labelnames.

All this has been done. I have lots of experience with layouts through both the designer and in code but never with adding text from an ARRAY in code to a layout created in the Designer. Here are the pertinent lines from my program. Sports, Religion and Education are all the names of labels added in the designer layout.

B4X:

Sub Globals
Dim Sports As Label
Dim Religion As Label
Dim Education As Label
Dim ThisField(3) as Label
ThisField = Array as Label(Sports, Religion, Education)
...
Activity.LoadLayout("MyLayout")
ThisField(0).Text = "Baseball"

I still get the run time error "Object should first be initialized (Label)".

DonManfred · Jan 20, 2017

You need to load the layout FIRST

B4X:

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.
    Private Sports As Label
    Private Religion As Label
    Private Education As Label
    Dim ThisField(3) As Label

End Sub
Sub Activity_Create(FirstTime As Boolean)
    Activity.LoadLayout("LayoutLabels")
    ThisField = Array As Label(Sports,Religion,Education)
    ThisField(0).Text = "Test"

DickD · Jan 20, 2017

DonManfred said:

You need to load the layout FIRST

B4X:

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.
    Private Sports As Label
    Private Religion As Label
    Private Education As Label
    Dim ThisField(3) As Label

End Sub
Sub Activity_Create(FirstTime As Boolean)
    Activity.LoadLayout("LayoutLabels")
    ThisField = Array As Label(Sports,Religion,Education)
    ThisField(0).Text = "Test"

Yes, that did it. Thanks. I tried every possible variation... except that one. Is this documented somewhere? I lost an 8 hour work day trying to figure this out.

Mahares · Jan 20, 2017

DickD said:
Is this documented somewhere? I lost an 8 hour work day trying to figure this ou

There is a little bit of info about it, See this thread and post #5 by Erel:
https://www.b4x.com/android/forum/threads/array-of-views-in-designer.8577/#post-47924
By the way, be generous with your 'Like' to @DonManfred. He saved you another 8 hours.

KMatle · Jan 20, 2017

DickD said:
I tried every possible variation

No. For sure NOT

DickD said:
Is this documented somewhere?

See the beginners guide and how to work with views and of course to work with arrays. Of course you will not find your exact issue.

DickD said:
I lost an 8 hour work day trying to figure this out

Welcome to the world of developers. I promise you WILL "lose" much more time than this solving a problem The time isn't lost. It is a time to learn new things.

DonManfred · Jan 21, 2017

DickD said:
Is this documented somewhere?

I´m sure it is documented in the beginners guide.

Objects which are in a layout are initialized when loading the layout! You can use the objects only if the activity "knows" them.
That´s the point

Android Question How to update label.Text from an array

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