UIButton不能显示，直到我点击她的超级视图

Question

UIButton *submitBtn = [UIButton buttonWithType:UIButtonTypeCustom]; 

submitBtn.frame=CGRectMake(48, 145, 62, 24); 

[submitBtn setBackgroundImage:[UIImage imageNamed:@"images/public/submit.png"] forState:UIButtonTypeCustom]; 

[submitBtn addTarget:self action:@selector(btnAction:) forControlEvents:UIControlEventTouchUpInside]; 

[submitBtn setNeedsDisplay]; 

[self addSubview:submitBtn]; 

我已经创建视图A和添加视图B在视图A中，视图B有一个submitbtn UIbutton！

为什么这个submitbtn按钮不能显示！ 但我点击他的超级视图，它可以再次显示！

Answer 1

添加超级查看此BTN

[self.view bringSubviewToFront:object_Btn]; 

试试这个