我正在以编程方式在UINavigationItem中创建RightBarButtonItem。使用这个简单的代码UIButton*backButton=[[UIButtonalloc]initWithFrame:CGRectMake(0,0,30,30)];[backButtonsetImage:[UIImageimageNamed:@"concate_back_icon.png"]forState:UIControlStateNormal];[backButtonaddTarget:selfaction:@selector(backButtonClicked:)forControlE