如何显示没有边框的UIBarButtonItem？

Question

在IB中我可以选择一个UIBarButtonItem,将它设置为Plain,Custom并应用一个Image,它在UIToolbar或UINavigationBar中看起来很好.

当我尝试在代码中执行此操作时,我得到一个边框:

backButton = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"arrowBack"] 
                                                  style:UIBarButtonItemStylePlain 
                                                 target:self 
                                                 action:@selector(backButtonClicked:)];

如何获得没有边框的UIBarButtonItem？我希望它是平原和自定义

Answer 1

这适用于我(leftButton的示例):

 UIButton *bt=[UIButton buttonWithType:UIButtonTypeCustom];
 [bt setFrame:CGRectMake(0, 0, 15, 30)];
 [bt setImage:[UIImage imageNamed:@"backBT"] forState:UIControlStateNormal];
 [bt addTarget:self action:@selector(popViewController:) forControlEvents:UIControlEventTouchUpInside];
 UIBarButtonItem *leftButton=[[UIBarButtonItem alloc] initWithCustomView:bt];
 self.navigationItem.leftBarButtonItem=leftButton;