改动UINavigationBar （导航栏）上NavigationBarItem 的字体大小和颜色的用法

//创建一个左边button

UIBarButtonItem *leftButton = [[UIBarButtonItem
alloc] initWithTitle:@"<"
style:UIBarButtonItemStylePlain
target:self
action:@selector(clickLeftButton)];

//    leftButton.

[leftButton setTitleTextAttributes:[NSDictionary
dictionaryWithObjectsAndKeys:

[UIFont
fontWithName:@"Helvetica-Bold"
size:17.0],
NSFontAttributeName,

[UIColor
greenColor], NSForegroundColorAttributeName,

nil]

forState:UIControlStateNormal];

//创建一个右边button

UIBarButtonItem *rightButton = [[UIBarButtonItem
alloc] initWithTitle:@"登陆"
style:UIBarButtonItemStyleDone
target:self
action:@selector(clickRightButton)];

[rightButton setTitleTextAttributes:[NSDictionary
dictionaryWithObjectsAndKeys:

[UIFont
fontWithName:@"Helvetica-Bold"
size:17.0],
NSFontAttributeName,

[UIColor
greenColor], NSForegroundColorAttributeName,

nil]

forState:UIControlStateNormal];