在iOS开发中使用iconfont图标

在开发iOS项目时，不可避免的会用到图标，而为了适配不同分辨率的设备，我们通常会需要@2x，@3x两套格式的图片，最明显的就是底部tabBar的图标使用。而对于那些有换肤需求的APP来说，还需要多套图来匹配不同的主题。通过切图的方式制作图标，一方面加大了开发者和设计者的工作量，另一方面也会增大APP的体积。而使用iconfont的可以达到以下目的

1.减小应用体积，字体文件比图片要小；

2.图标保真缩放，解决2x/3x乃至将来nx图问题；

3.方便更改图标颜色大小，图片复用。

所以为了给开发者、设计者稍微减少点工作量，给APP“减重，我们可以将iconfont应用到自己的项目中。那么，iconfont是怎么用的呢？iconfont，从字面上就能理解它就是字体，让开发者像使用字体一样使用图标。

由于我是做开发的，所以对于iconfont的制作并不太熟悉，都是设计师做好了图标给我，如果你想学习iconfont的制作的话，可以去阿里巴巴的iconfont平台去看看，上面有比较全的资料。制作好的iconfont图标是一种.ttf格式的字体，如图：



iconfont图标

iconfont中的图标是这样的：



iconfont中的图标

而我们需要的是将.ttf格式的文件引入到自己的工程中

接下来我们借助淘点点科技写的一个关于iconfont封装，方便我们使用iconfont。iconfont的封装包括



iconfont

1.TBCityIconInfo.h的实现

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

@interface TBCityIconInfo : NSObject

@property (nonatomic, strong) NSString *text;
@property (nonatomic, assign) NSInteger size;
@property (nonatomic, strong) UIColor *color;

- (instancetype)initWithText:(NSString *)text size:(NSInteger)size color:(UIColor *)color;
+ (instancetype)iconInfoWithText:(NSString *)text size:(NSInteger)size color:(UIColor *)color;

@end

2.TBCityFontImageInfo.m的实现

#import "TBCityIconInfo.h"

@implementation TBCityIconInfo

- (instancetype)initWithText:(NSString *)text size:(NSInteger)size color:(UIColor *)color {
if (self = [super init]) {
self.text = text;
self.size = size;
self.color = color;
}
return self;
}

+ (instancetype)iconInfoWithText:(NSString *)text size:(NSInteger)size color:(UIColor *)color {
return [[TBCityIconInfo alloc] initWithText:text size:size color:color];
}

@end

3.TBCityIconFont.h的实现

#import "UIImage+TBCityIconFont.h"
#import "TBCityIconInfo.h"

#define TBCityIconInfoMake(text, imageSize, imageColor) [TBCityIconInfo iconInfoWithText:text size:imageSize color:imageColor]

@interface TBCityIconFont : NSObject

+ (UIFont *)fontWithSize: (CGFloat)size;
+ (void)setFontName:(NSString *)fontName;

@end

4.TBCityIconFont.m的实现

#import "TBCityIconFont.h"
#import <CoreText/CoreText.h>

@implementation TBCityIconFont

static NSString *_fontName;

+ (void)registerFontWithURL:(NSURL *)url {
NSAssert([[NSFileManager defaultManager] fileExistsAtPath:[url path]], @"Font file doesn't exist");
CGDataProviderRef fontDataProvider = CGDataProviderCreateWithURL((__bridge CFURLRef)url);
CGFontRef newFont = CGFontCreateWithDataProvider(fontDataProvider);
CGDataProviderRelease(fontDataProvider);
CTFontManagerRegisterGraphicsFont(newFont, nil);
CGFontRelease(newFont);
}

+ (UIFont *)fontWithSize:(CGFloat)size {
UIFont *font = [UIFont fontWithName:[self fontName] size:size];
if (font == nil) {
NSURL *fontFileUrl = [[NSBundle mainBundle] URLForResource:[self fontName] withExtension:@"ttf"];
[self registerFontWithURL: fontFileUrl];
font = [UIFont fontWithName:[self fontName] size:size];
NSAssert(font, @"UIFont object should not be nil, check if the font file is added to the application bundle and you're using the correct font name.");
}
return font;
}

+ (void)setFontName:(NSString *)fontName {
_fontName = fontName;

}

+ (NSString *)fontName {
return _fontName ? : @"iconfont";
}

@end

5.UIImage+TBCityIconFont.h的实现

#import <UIKit/UIKit.h>
#import "TBCityIconInfo.h"

@interface UIImage (TBCityIconFont)

+ (UIImage *)iconWithInfo:(TBCityIconInfo *)info;

@end

6.UIImage+TBCityIconFont.m

#import "UIImage+TBCityIconFont.h"
#import "TBCityIconFont.h"
#import <CoreText/CoreText.h>

@implementation UIImage (TBCityIconFont)

+ (UIImage *)iconWithInfo:(TBCityIconInfo *)info {
CGFloat size = info.size;
CGFloat scale = [UIScreen mainScreen].scale;
CGFloat realSize = size * scale;
UIFont *font = [TBCityIconFont fontWithSize:realSize];
UIGraphicsBeginImageContext(CGSizeMake(realSize, realSize));
CGContextRef context = UIGraphicsGetCurrentContext();

if ([info.text respondsToSelector:@selector(drawAtPoint:withAttributes:)]) {
/**
* 如果这里抛出异常，请打开断点列表，右击All Exceptions -> Edit Breakpoint -> All修改为Objective-C
* See: http://stackoverflow.com/questions/1163981/how-to-add-a-breakpoint-to-objc-exception-throw/14767076#14767076 */
[info.text drawAtPoint:CGPointZero withAttributes:@{NSFontAttributeName:font, NSForegroundColorAttributeName: info.color}];
} else {

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
CGContextSetFillColorWithColor(context, info.color.CGColor);
[info.text drawAtPoint:CGPointMake(0, 0) withFont:font];
#pragma clang pop
}

UIImage *image = [UIImage imageWithCGImage:UIGraphicsGetImageFromCurrentImageContext().CGImage scale:scale orientation:UIImageOrientationUp];
UIGraphicsEndImageContext();

return image;
}

@end

7.在AppDelegate.m中，初始化我们的iconfont

#import "AppDelegate.h"
#import "TBCityIconFont.h"
#import "ViewController.h"
@interface AppDelegate ()

@end

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
//iconfont图标
[TBCityIconFont setFontName:@"iconfont"];
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:[ViewController new]];
_window.rootViewController = nav;
// Override point for customization after application launch.
return YES;
}

8.在ViewController.m中实现

#import "ViewController.h"
#import "TBCityIconFont.h"
#import "UIImage+TBCityIconFont.h"
@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
self.navigationController.navigationBar.translucent = NO;

UIBarButtonItem *leftBarButton = [[UIBarButtonItem alloc] initWithImage:[ UIImage iconWithInfo:TBCityIconInfoMake(@"\U0000e602",22,[UIColor colorWithRed:0.55 green:0.55 blue:0.55 alpha:1])] style:UIBarButtonItemStylePlain target:self action:@selector(leftButtonAction)];
self.navigationItem.leftBarButtonItem = leftBarButton;

self.navigationItem.leftBarButtonItem.tintColor = [UIColor colorWithRed:0.55 green:0.55 blue:0.55 alpha:1];
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage iconWithInfo:TBCityIconInfoMake(@"\U0000e60d",25, [UIColor colorWithRed:0.14 green:0.61 blue:0.83 alpha:1.00])] style:UIBarButtonItemStylePlain target:self action:@selector(rightButtonAction)];
self.navigationItem.rightBarButtonItem.tintColor = [UIColor colorWithRed:0.14 green:0.61 blue:0.83 alpha:1.00];

// Do any additional setup after loading the view, typically from a nib.
}

-(void)loadView{
[super loadView];
//    imageView
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(100, 50, 30, 30)];
[self.view addSubview:imageView];
//图标编码是，需要转成\U0000e603
imageView.image = [UIImage iconWithInfo:TBCityIconInfoMake(@"\U0000e603", 30, [UIColor redColor])];
//    button
UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];
button.frame = CGRectMake(100, 100, 40, 40);
[self.view addSubview:button];
[button setImage:[UIImage iconWithInfo:TBCityIconInfoMake(@"\U0000e60c", 40, [UIColor redColor])] forState:UIControlStateNormal];
//    label,label可以将文字与图标结合一起，直接用label的text属性将图标显示出来
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(50, 160, 280, 40)];
[self.view addSubview:label];
label.font = [UIFont fontWithName:@"iconfont" size:15];//设置label的字体
label.text = @"这是用label显示的iconfont  \U0000e60c";
}
-(void)leftButtonAction{

}
-(void)rightButtonAction{

}

9.运行得到的结果如图：



iconfont图标示例

这样，我们就可以很方便的使用iconfont图标了。这里要注意的是，图标是用的iconfont中的图标用的是unicode编码，我们在自己的工程中时需要将&#xXXXX格式转换成\UXXXXXXXX格式。

文／若锦（简书作者）

原文链接：http://www.jianshu.com/p/3b10bb95b332

著作权归作者所有，转载请联系作者获得授权，并标注“简书作者”。