Xcode [ESC] fail to auto complete the property in .m file

I have declared a property in the header file, for example

@interface myClass {
    NSArray* data;
}
@property (nonatomic, retai开发者_StackOverflow中文版n) NSArray* data;

when I want to synthesize it in the .m file, I press 'ESC' and expect the property 'data' will appear in the list but it doesn't ?

@implementation
@synthesize da[ESC]

It prompts 'No completions found'

any help? many thanks ~

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It sometimes takes a little while for Xcode to update its autocomplete database. Unlike the Visual Studio IDE, it's not done instantly with any code change.