UITextView style is being reset after setting text property

If you want your text view to be "read only" you can check Editable and Selectable and uncheck User Interaction Enabled, with this the UITextView was behaving as I wanted

Sitting with this for hours, I found the bug. If the property "Selectable" = NO it will reset the font and fontcolor when setText is used.

So turn Selectable ON and the bug is gone.

Had this issue myself and the above answer helped but I added a wrapper to my ViewController code as follows and just pass the uiview instance and text to change and the wrapper function toggles the Selectable value on, changes text and then turns it off again. Helpful when you need the uitextview to be off at all times by default.

/*
    We set the text views Selectable value to YES temporarily, change text and turn it off again.
    This is a known bug that if the selectable value = NO the view loses its formatting.
 */
-(void)changeTextOfUiTextViewAndKeepFormatting:(UITextView*)viewToUpdate withText:(NSString*)textValue
{
    if(![viewToUpdate isSelectable]){
        [viewToUpdate setSelectable:YES];
        [viewToUpdate setText:textValue];
        [viewToUpdate setSelectable:NO];
    }else{
        [viewToUpdate setText:textValue];
        [viewToUpdate setSelectable:NO];
    }
}

I ran into the same issue (on Xcode 6.1) and while John Cogan's answer worked for me, I found that extending the UITextView class with a category was a better solution for my particular project.

interface

@interface UITextView (XcodeSetTextFormattingBugWorkaround)
    - (void)setSafeText:(NSString *)textValue;
@end

implementation

@implementation UITextView (XcodeSetTextFormattingBugWorkaround)
- (void)setSafeText:(NSString *)textValue
{
    BOOL selectable = [self isSelectable];
    [self setSelectable:YES];
    [self setText:textValue];
    [self setSelectable:selectable];
}
@end