Android Question How to use a B4XTable from other B4XPage?

[pliroforikos]

Hi everyone

I have an app with several B4XPages. Every B4Xpage shows data from different tables of a database from web into B4XTables.

My question is this: Can i use a B4XTable from (for example) B4XPage1 to B4XPage2 without creating new B4XTable or downloading data from database.

In B4XPage2 I made a form with VD with a panel (with name panel1) and inside a B4XTable named B4XTable1 (the same name as B4XPage1)
The code bellow is what i did to B4XPage2

    Private B4XPp1 As B4XPage1
    B4XPp1.Initialize

and when i hit the button btnInsert i want to show panel1 with B4XTable from B4XPage1 and also later i want to customize display with .CreateDataView.
So:

Sub btnInsert_Click
    panel1.Visible = True

' And now i am stuck!!!

End Sub

I will be greatfull with any advice.

 

[Erel]

Can i use a B4XTable from (for example) B4XPage1 to B4XPage2 without creating new B4XTable or downloading data from database.

Yes.

Dim t As B4XTable = B4XPage8.Table1
t.mBase.RemoveViewFromParent
Root.AddView(t.mBase, 0, 0, Root.Width, Root.Height)

 

[pliroforikos]

Thank you very much but forgive my ignorance as i don't understand how to use it.
so 3 lines of code and 4 questions!

1. The

t.mBase.RemoveFromParent

maybe is

t.mBase.RemoveRemoveViewFromParent

I cant find RemoveFromParent

2.
Do i have to make a variable mBase as B4XView in B4XPage2 ?


3. What aboout Root is the same Root of B4XPage2 ?

4.
When i am compiling the code it shows:
Root.AddView(t, 0, 0, Root.Width, Root.Heigh)
src\b4a\mySxoleiov2\b4xpagemylessons.java:734: error: incompatible types: b4xtable cannot be converted to View
Maybe i have to use panel not B4XTable in AddView?

thank you again

 

[Erel]

1. RemoveViewFromParent.

2. mBase is the "root" view of B4XTable (and most custom views). You don't need to add any variable.

3. Not sure what you mean.

4. My mistake. It should be Root.AddView(t.mBase, ...)

I've updated the code.

 

[pliroforikos]

Thank you, in

t.mBase.RemoveViewFromParent

shows
java.lang.NullPointerException: Attempt to invoke virtual method 'void anywheresoftware.b4a.objects.B4XViewWrapper.RemoveViewFromParent()' on a null object reference

any idea?

 

[pliroforikos]

Trying to figure out how it is working i made a small project with this problem. If anyone can help is welcome!

 

[Erel]

The problem is here:

Dim page1 As B4XPage1
    page1.Initialize

You should never initialize B4XPages yourself.
You have created a new B4XPage1 which has nothing to do with the "real" B4XPage1.

There are many ways to access other pages, here is one:

'B4XMainPage:
Sub Class_Globals
    Private Root As B4XView
    Private xui As XUI
    Public pg1 As B4XPage1 '<-- make public
    Private pg2 As B4Xpage2

End Sub

B4XPage2:

Dim t As B4XTable = B4XPages.MainPage.pg1.B4XTable1
t.mBase.RemoveViewFromParent
Root.AddView(t.mBase, 0, 0, Root.Width, Root.Height)

Important tip:
Your code will crash if the user goes to page2 before showing page1. There is a simple solution:

B4XPages.AddPageAndCreate("page1", pg1) 'change AddPage

This way page1 will be created immediately when the app starts.