I create a UILabel object in viewDidLoad of UIViewController like below:
language(void) viewDidLoad {
[super viewDidLoad];
UILabel *tt = [UILabel new];
tt.text = @"abcd";
tt.frame = CGRectMake(100, 100, 100, 50);
tt.backgroundColor = nil;
[self.view addSubview:tt];
}
I set the tt.backgroundColor is nil。 but when UILabel appeared, the backgroundColor is black ! and I adjust tt.text=@"abcd中"。 the backgroundColor is working and the color is clear。
PS:
Xcode version :11.3 (11C29)
iPhone11 simulator。
ouyang2013
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I have a sample code to test c++ virtual deconstructor like below:
#include <iostream>
class CA {
public:
virtual ~CA() {
std::cout<< "~CA" << std::endl;
}
};
class CB :public CA {
public:
virtual ~CB() {
std::cout<< "~CB" << std::endl;
}
};
int main(int argc, const char * argv[]) {
CA *pb = new CB[3];
delete []pb;
return 0;
}
in xcode this code print out result is :
~CA
~CA
~CA
but in other compilers like visual studio C++ and gcc the print out result is:
~CB
~CA
~CB
~CA
~CB
~CA
I think this is a dynamic delete array object with virtual deconstructor bug in xcode compiler 。 because the print result is not conform to C++ form。