自定义圆角按钮

    //放置按钮

    //登录

    _loginButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];

    _loginButton.frame = CGRectMake(20, 300, 280, 35);

    _loginButton.backgroundColor = [UIColor blueColor];

    [_loginButton setTitle:@"登录" forState:UIControlStateNormal];

    //自定义 圆角按钮

    [_loginButton.layer setMasksToBounds:YES];

    [_loginButton.layer setCornerRadius:4.0];

    //[_loginButton.layer setBorderWidth:1.0];

    [self addSubview:_loginButton];