Hi unais,
If you work with a "String" in the GUI (Chora, within Embedded Wizard Studio) and you generate the code for C, it will create an XString as a representation of the String.
That means also (the other way around), if you pass an XString to GUI, it should end up with in a String.
Usually there are two use cases:
1. Function in DeviceDriver / C: Create XString in DeviceDriver and pass it to GUI:
void UpdateValue( char* aValue )
{
XString valStr = EwNewStringAnsi( (char*)aValue );
DeviceDeviceClass__UpdateString( DeviceObject, valStr );
}
Within the GUI, inside the DeviceClass there is a function UpdateString( string ), which is called via DeviceDriver.
2. Function in DeviceClass / Chora: Get String from device (e.g. middleware) and pass it to UI component:
GetStatus()
{
// The variable should receive some device status information.
var string status = "";
$if !$prototyper
native ( status )
{
char buf[256];
int voltage;
int current;
/* Call some functions to get the status information of the device */
voltage = device_get_voltage();
current = device_get_current();
/* Format a status message in the temporary buffer 'buf' */
sprintf( buf, "STATUS: %d Centigrade, %d Volt, %d Ampere", voltage, current );
/* From the ANSI string in 'buf' create Embedded Wizard string and
return it in the variable 'status'. */
status = EwNewStringAnsi( buf );
}
$endif
// 'status' contains now the message as a correct string.
return status;
}
Within the GUI, inside the DeviceClass there is a function GetStatus(), which is called via GUI and grabs the strings from C, creates and returns an XString .
See also: https://doc.embedded-wizard.de/integrating-with-the-device?v=11.00#6
Hope this helps,
Chris
