Android Question Load Layout from Class

[aaronk]

Hi,

I am trying to load a layout I created in the designer using a class and trying to set values to object in that layout but having issues in doing it.

My Main Activity looks like this:

Main:

Sub Process_Globals
	'These global variables will be declared once when the application starts.
	'These variables can be accessed from all modules.

End Sub

Sub Globals
	'These global variables will be redeclared each time the activity is created.
	'These variables can only be accessed from this module.
	Dim MyClassDemo As MyClass 
	Private Label1 As Label
End Sub

Sub Activity_Create(FirstTime As Boolean)
	'Do not forget to load the layout file created with the visual designer. For example:
	'Activity.LoadLayout("Layout1")
	
	MyClassDemo.Initialize(Activity)
	Label1.text = "hello this is a test"
	
End Sub

Sub Activity_Resume

End Sub

Sub Activity_Pause (UserClosed As Boolean)

End Sub

The Class looks like this:

MyClass:

'Class module
Sub Class_Globals
	Dim MyActivity As Activity
End Sub

'Initializes the object. You can add parameters to this method if needed.
Public Sub Initialize(act As Activity)
	MyActivity = act
	MyActivity.LoadLayout("demo")
End Sub

My Layout file is called 'Demo' and that just has one label called 'label1'.

When I try to change the text after loading the layout it says 'Object should first be initialized (Label).'

PackageAdded: package:b4a.example.classdemo
** Activity (main) Create, isFirst = true **
java.lang.RuntimeException: Object should first be initialized (Label).
	at anywheresoftware.b4a.AbsObjectWrapper.getObject(AbsObjectWrapper.java:46)
	at anywheresoftware.b4a.objects.TextViewWrapper.setText(TextViewWrapper.java:39)
	at b4a.example.classdemo.main._activity_create(main.java:303)
	at java.lang.reflect.Method.invokeNative(Native Method)
	at java.lang.reflect.Method.invoke(Method.java:525)
	at anywheresoftware.b4a.BA.raiseEvent2(BA.java:174)
	at b4a.example.classdemo.main.afterFirstLayout(main.java:98)
	at b4a.example.classdemo.main.access$100(main.java:16)
	at b4a.example.classdemo.main$WaitForLayout.run(main.java:76)
	at android.os.Handler.handleCallback(Handler.java:730)
	at android.os.Handler.dispatchMessage(Handler.java:92)
	at android.os.Looper.loop(Looper.java:213)
	at android.app.ActivityThread.main(ActivityThread.java:5225)
	at java.lang.reflect.Method.invokeNative(Native Method)
	at java.lang.reflect.Method.invoke(Method.java:525)
	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:741)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
	at dalvik.system.NativeStart.main(Native Method)
** Activity (main) Resume **

However, I then tried to load the layout without using the class, and loaded it using the following code and it works fine:

Main:

Sub Process_Globals
	'These global variables will be declared once when the application starts.
	'These variables can be accessed from all modules.

End Sub

Sub Globals
	'These global variables will be redeclared each time the activity is created.
	'These variables can only be accessed from this module.
	
	Private Label1 As Label
End Sub

Sub Activity_Create(FirstTime As Boolean)
	'Do not forget to load the layout file created with the visual designer. For example:
	Activity.LoadLayout("Demo")

	Label1.text = "hello this is a test"
	
End Sub

Sub Activity_Resume

End Sub

Sub Activity_Pause (UserClosed As Boolean)

End Sub

Do I need to initialize the label even knowing I am calling it from a layout I created in the designer when I call it from a class ?

In my example I am trying to load the layout from a class and then change the text of the label from my activity.

 

[derez]

You are mixing two label1 !
The one in the class is initialized by the layout but you are not calling it, you call label1 which is in the main activity, and that one is not initialized.
To call the class label you should use MyClassDemo.label1 (after changing its declaration to public) , or allocate a method in the class to put text to the label.