Issues with the data when screen update and dynamically loaded images .

asked Jan 15 in GUI Development by varunshatagopam

Hi ,

I have some querying regarding the screen updation and dynamically loading of images.

Query 1:


1.There are two buttons on the main Application GUI (Mode and Speed).

2.If i am clicking on the button Mode it is going to the ModeSetting screen which contains 3 buttons (Auto,cool,heat).

3.If i am clicking on the button Speed it is going to the SpeedSetting screen which contains 3 button(high,low and medium).

4.Default on the Main Application GUI the text under the Mode is heat. On the prototying window from main Application i am moving to  Modesetting screen i am updating the text heat to cool on the main Application when i click the button cool on the ModeSetting screen .

5.In the main Application GUI the text is updated to cool .then i am clicking on the Speed it is going to SpeedSetting screen where i am changing the main application GUI screen text under speed to medium (default i kept as low). 

6.From SpeedSetting screen when it is coming back the text under Speed is updated to medium  but the text under mode is displaying the default value i.e.., heat. At runtime i have changed to cool .that data is lost .

GUI screen attached for your reference.

Please help me how to handle the data of  screens at runtime and how to store them.

Query 2:

Can we add the .c and .h files to our Embedded wizard Application if yes then how to link the files to our Embedded wizard Application .

Query 3:

I want to change the image dynamically at runtime i tried using the externBitmap . I am getting error call to unknown method EwLoadExternBitmap() , i need to implement this function but where to implement this function and where to add the #includes and if you have any demo projects please send me for reference .

Thanks in Advance .



varun kumar



1 Answer

0 votes
answered Jan 16 by Manfred Schweyer

Hello Varun Kumar,

Q1) It is difficult to find the root cause of the "lost data" without seeing the implementation. But I assume that you store the data of your device in a device class (see chapter Implementing a Device Interface). Typically, this device class is accessed as autoobject.

Please consider the livetime of autoobjects. Everytime, the autoobject is no more in use, the instance will be deleted by the Garbage Collector. Within the Prototyper on PC, the Garabage Collector is running after a couple of seconds - this explains, why you get sometimes the expected value and why the content is lost after some seconds. 

In order to prevent the Garbage Collector from freeing an autoobject, please add a variable to the root class, set the type to your class Application::Device and the value to the instance (autoobject) of the class. 

Q2) No, you cannot include any C/H filles into an Embedded Wizard project. Please note, that Embedded Wizard generates the code of your GUI project. You can add this generated code, together with your other C code (e.g. your hardware drivers, the BSP, the operating system) into your C development toolchain.

Q3) Let me refer to the chapter Displaying dynamically loaded images and Extern Bitmap interface of our online documentaton. There you will find all the necessary background information as well as some examples.

Best regards,


commented Jan 17 by varunshatagopam
Thanks Manfred

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