How to set text in Carbon textfield on OSX?

Question

I'm trying to set the text of a textfield using the Carbon API like this:

ControlID editId = {'EDIT', 3};
ControlRef ctrl;
GetControlByID(GetWindowRef(), &editId, &ctrl);
CFStringRef title = CFSTR("Test");      
OSErr er = SetControlData(ctrl, kControlEntireControl, kControlEditTextTextTag, CFStringGetLength(title), title);
CFRelease(title);

I'm using the C++ code template of XCode, so GetWindowRef() is a call to the predefined TWindow class. The OSErr return value gives me noErr, but my textfield only contains garbage. It doesn't matter if I set the attribute of my textfield to Unicode or not.

Any ideas what is wrong here?

Answer 1

What does the GetControlID(...) return? Is it noErr?

As a ControlRef is also a HIViewRef, you can also use the function:

HIViewSetText to set the text. This is documented to work with functions that accept kControlEditTextCFStringTag.

By the way, the line you wrote:

CFRelease(title);

Will cause problems. One should only release objects that have been made using functions that have Create or Copy in the API name. You'll want to read: "Introduction to Memory Management Programming Guide for Core Foundation" -- search in the Xcode documentation.