【读书笔记】UIFont-动态下载系统提供的字体-官方代码

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    // Override point for customization after application launch.            ViewController *view=[[ViewController alloc]init];    UINavigationController *nav=[[UINavigationController alloc]initWithRootViewController:view];    self.window.backgroundColor=[UIColor whiteColor];    self.window.rootViewController=nav;                return YES;}

#import <UIKit/UIKit.h>@interface ViewController : UIViewController<UITableViewDelegate,UITableViewDataSource>{    UITableView *myTableView;    NSArray *fontNames;    NSArray *fontSamples;}@end

#import "ViewController.h"#import <CoreText/CoreText.h>@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.        //初始化数据    [self addData];    //初始化界面    [self addView];    }#PRagma -mark -functions//初始化界面-(void)addView{    myTableView=[[UITableView alloc]initWithFrame:CGRectMake(0, 100, 320, 200)];    myTableView.delegate=self;    myTableView.dataSource=self;    [self.view addSubview:myTableView];}//初始化数据-(void)addData{    fontNames = [[NSArray alloc] initWithObjects:                 @"STXingkai-SC-Light",                 @"DFWaWaSC-W5",                 @"FZLTXHK--GBK1-0",                 @"STLibian-SC-Regular",                 @"LiHeipro",                 @"HiraginoSansGB-W3",                 nil];    fontSamples = [[NSArray alloc] initWithObjects:                   @"汉体书写信息技术标准相",                   @"容档案下载使用界面简单",                   @"支援服务升级资讯专业制",                   @"作创意空间快速无线上网",                   @"兙兛兞兝兡兣嗧瓩糎",                   @"㈠㈡㈢㈣㈤㈥㈦㈧㈨㈩",                   nil];}#pragma -mark -UITableViewDelegate- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{    return [fontNames count];}- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{    static NSString *MyIdentifier = @"MyIdentifier";        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];    if (cell == nil) {        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MyIdentifier];    }    cell.textLabel.text = fontNames[indexPath.row];        return cell;}- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{    [self asynchronouslySetFontName:fontNames[indexPath.row]];}#pragma -mark -functions//字体开始进行下载- (void)asynchronouslySetFontName:(NSString *)fontName{    UIFont* aFont = [UIFont fontWithName:fontName size:12.];    //判断字体是否已经被下载    if (aFont && ([aFont.fontName compare:fontName] == NSOrderedSame || [aFont.familyName compare:fontName] == NSOrderedSame)) {        NSLog(@"字体已经被下载");        return;    }        //用字体的PostScript名字创建一个Dictionary    NSMutableDictionary *attrs = [NSMutableDictionary dictionaryWithObjectsAndKeys:fontName, kCTFontNameAttribute, nil];        // 创建一个字体描述对象CTFontDescriptorRef    CTFontDescriptorRef desc = CTFontDescriptorCreateWithAttributes((__bridge CFDictionaryRef)attrs);        //将字体描述对象放到一个NSMutableArray中    NSMutableArray *descs = [NSMutableArray arrayWithCapacity:0];    [descs addObject:(__bridge id)desc];    CFRelease(desc);        __block BOOL errorDuringDownload = NO;        //开始对字体进行下载    CTFontDescriptorMatchFontDescriptorsWithProgressHandler( (__bridge CFArrayRef)descs, NULL,  ^(CTFontDescriptorMatchingState state, CFDictionaryRef progressParameter) {                NSLog( @"state %d - %@", state, progressParameter);                double progressValue = [[(__bridge NSDictionary *)progressParameter objectForKey:(id)kCTFontDescriptorMatchingPercentage] doubleValue];                        if (state == kCTFontDescriptorMatchingDidBegin) {            dispatch_async( dispatch_get_main_queue(), ^ {                NSLog(@"字体已经匹配");                });        } else if (state == kCTFontDescriptorMatchingDidFinish) {            dispatch_async( dispatch_get_main_queue(), ^ {                NSLog(@"字体下载完成");                      // Log the font URL in the console                CTFontRef fontRef = CTFontCreateWithName((__bridge CFStringRef)fontName, 0., NULL);                CFStringRef fontURL = CTFontCopyAttribute(fontRef, kCTFontURLAttribute);                CFRelease(fontURL);                CFRelease(fontRef);                                if (!errorDuringDownload) {                    NSLog(@"%@ downloaded", fontName);                }            });        } else if (state == kCTFontDescriptorMatchingWillBeginDownloading) {            dispatch_async( dispatch_get_main_queue(), ^ {                NSLog(@"字体开始下载");            });        } else if (state == kCTFontDescriptorMatchingDidFinishDownloading) {            dispatch_async( dispatch_get_main_queue(), ^ {                NSLog(@"字体下载完成");                });        } else if (state == kCTFontDescriptorMatchingDownloading) {            dispatch_async( dispatch_get_main_queue(), ^ {                NSLog(@"下载进度");            });        } else if (state == kCTFontDescriptorMatchingDidFailWithError) {            NSLog(@"下载失败");                        NSError *error = [(__bridge NSDictionary *)progressParameter objectForKey:(id)kCTFontDescriptorMatchingError];            if (error != nil) {                NSLog(@"errorMessage--%@-",[error description]);            } else {                NSLog(@"error message is not available");            }            errorDuringDownload = YES;            dispatch_async( dispatch_get_main_queue(), ^ {                NSLog(@"Download error: %@", [error description]);            });        }                return (bool)YES;    });    }- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end