ios开发随记 用navigationbar 当栏 可以免于ios 7 和6 上下错位

 UIButton *searchBtn=[UIButton buttonWithType:UIButtonTypeCustom];        searchBtn.frame = CGRectMake(0, 0, 51, 30);        [searchBtn setBackgroundImage:[UIImage imageNamed:@"but_rightbg.png"] forState:UIControlStateNormal];        [searchBtn setTitle:@"编辑" forState:UIControlStateNormal];        [searchBtn addTarget:self action:@selector(editBtnClick:) forControlEvents:UIControlEventTouchUpInside];        UIBarButtonItem *searchButton = [[UIBarButtonItem alloc] initWithCustomView:searchBtn];        self.navigationItem.rightBarButtonItem= searchButton;                UIButton *backBtn=[UIButton buttonWithType:UIButtonTypeCustom];        backBtn.frame = CGRectMake(0, 0, 24, 24);        [backBtn setBackgroundImage:[UIImage imageNamed:@"icon_back.png"] forState:UIControlStateNormal];        [backBtn addTarget:self action:@selector(backBtnClick) forControlEvents:UIControlEventTouchUpInside];        UIBarButtonItem *backBtn1 = [[UIBarButtonItem alloc] initWithCustomView:backBtn];        self.navigationItem.leftBarButtonItem= backBtn1;                UILabel *navTitle =[[UILabel alloc] initWithFrame:CGRectMake(200, 0,120, 44)];        navTitle.backgroundColor =[UIColor clearColor];        navTitle.text  = @"系统信息";        navTitle.font =[UIFont systemFontOfSize:28.0f];        navTitle.textColor =[UIColor whiteColor];        navTitle.textAlignment = NSTextAlignmentLeft;        //UIBarButtonItem *navTitleBtn = [[UIBarButtonItem alloc] initWithCustomView:navTitle];        // self.navigationItem.leftBarButtonItem= navTitleBtn;        self.navigationItem.titleView = navTitle ;

[self.firstNavView.navigationBar setBackgroundImage:[UIImage imageNamed:allNavImages] forBarMetrics:UIBarMetricsDefault];