Android Question Accessing views by Index

[toby]

I've found it's handy sometimes when you can access a view by its index if it's known. You don't have to use the GetAllViewsRecursive method and check the type (EditText is a special kind of Label, by the way) So I've done some tests and I've found the following
1. The index is based on the order it's added not the physical location it's placed.
2. Any view added to become the sibling of some existing XUI views (such as B4XPlusMinus and B4XFloatTextField) can not be accessed by index

Please guide me if my observations are incorrect.

Dim label1Index As Int=-1
    Dim Label2Index As Int=-1
    Dim i As Int=0
    For Each v As B4XView In Activity.GetAllViewsRecursive
        Log(i & ", " & v.Tag)
        
        If v.Tag  Is B4XPlusMinus Then
            Dim bpm As B4XPlusMinus=v.Tag
            LogColor("selected value=" & bpm.SelectedValue, Colors.Red)
            LogColor("bpm.tag=" & bpm.tag, Colors.Red)
        Else If v.Tag  Is B4XFloatTextField Then
            Dim fedt As B4XFloatTextField=v.Tag
            LogColor("selected text=" & fedt.Text, Colors.Red)
            LogColor("tag=" & fedt.tag, Colors.Red)
            
        else    If v Is Button Then
            Dim btn As Button=v
            LogColor("Button text=" & btn.Text, Colors.Red)
            LogColor("button tag=" & btn.tag, Colors.Red)
        Else if v Is EditText Then
            Dim edt As EditText=v
            LogColor("edittext: text=" & edt.Text & ", tag=" & edt.Tag, Colors.red)
        Else if v Is Spinner Then
            Dim spn As Spinner=v
            LogColor(" spinner1 selected item=" & spn.SelectedItem & ", tag=" & spn.Tag, Colors.red)
    
        Else if v Is Label Then
            'label
            Dim lbl As Label=v
            If lbl =Null Or lbl.Tag=Null Then Continue
            
            Select lbl.Tag
            Case "Label1"
                LogColor("lbl1: text=" & lbl.Text & ", tag=" & lbl.Tag, Colors.red)
                label1Index=i
            Case "Label2"
                LogColor("lbl2: text=" & lbl.Text & ", tag=" & lbl.Tag, Colors.red)
                Label2Index=i
        
            End Select
            
        End If
    
                    

        i = i +1
    Next
    
    If label1Index>=0 Then
        Dim lbl As Label=Activity.GetView(label1Index)
        LogColor("label1 text=" & lbl.Text, Colors.Red)
        LogColor("label1 tag=" & lbl.tag, Colors.Red)
    End If
    If Label2Index>=0 Then   
         'Label2 is the very last view  added
        lbl=Activity.GetView(Label2Index) '<==this line causes error
        LogColor("label2 text=" & lbl.Text, Colors.Red)
        LogColor("label2 tag=" & lbl.tag, Colors.Red)
    End If
 
End Sub

Spoiler: Error log

9, Label2
lbl2: text=Label2 text, tag=Label2
10, Spinner1
spinner1 selected item=Tuesday, tag=Spinner1
11, null
label1 text=Label1 text
label1 tag=Label1
Error occurred on line: 101 (Main)
java.lang.RuntimeException: Object should first be initialized (View).
at anywheresoftware.b4a.AbsObjectWrapper.getObject(AbsObjectWrapper.java:67)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:732)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:348)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:144)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:197)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:193)
at anywheresoftware.b4a.objects.ViewWrapper$1.onClick(ViewWrapper.java:80)
at android.view.View.performClick(View.java:6306)
at android.widget.TextView.performClick(TextView.java:11201)
at android.view.View$PerformClick.run(View.java:23962)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6823)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1557)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1445)

 

[DonManfred]

[B4X] How to get <custom view here> from <CLV or any other container>

 

[toby]

The following code is from the link provided by @DonManfred. How to get the y value?

Dim B4XFloatTextField1 As B4XFloatTextField = CLV.GetPanel(x).GetView(y)

 

[Erel]

It will not work unless you actually read the tutorial: