#import <UIKit/UIKit.h>

@interface RootViewController : UIViewController

@end

#import "RootViewController.h"

#import "Utils.h"

@interface RootViewController ()

@end

@implementation RootViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

{

    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

    if (self) {

        // Custom initialization

    }

    return self;

}

- (void)viewDidLoad

{

    [super viewDidLoad];

    // Do any additional setup after loading the view.

    //初始化背景图

    [self addView];

    //初始化button

    [self initButton];

}

#pragma -mark -functions

//初始化背景图

-(void)addView

{

    self.title=@"UIFont";

}

//初始化button

-(void)initButton

{

    UIButton *rightButton = [[UIButton alloc] initWithFrame:CGRectMake(50, 100, 100, 50)];

    [rightButton setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];

    rightButton.backgroundColor=[UIColor redColor];

    //给按钮上的字设置大小

    [Utils setDefaultFont:rightButton size:20];

    [rightButton setTitle:@"完成" forState:UIControlStateNormal];

    [self.view addSubview:rightButton];

}

- (void)didReceiveMemoryWarning

{

    [super didReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}

#import <Foundation/Foundation.h>

@interface Utils : NSObject

+ (void)setDefaultFont:(id)sender size:(float)size;

@end

#import "Utils.h"

@implementation Utils

//给某个按钮上的数字设置大小

+ (void)setDefaultFont:(id)sender size:(float)size{

    [sender setFont:[UIFont fontWithName:@"Helvetica" size:size]];

}

@end