1.使用系統默認提供的字體

系統默認提供的字體主要是指UIFont中提供的字體，其使用代碼為：

fontLabel.font = [UIFont fontWithName:@"Marion" size:17];

或者是通過字體詳細字典對字體屬性進行設置

/*
     UIFontDescriptorFamilyAttribute：設置字體家族名
     UIFontDescriptorNameAttribute  ：設置字體的字體名
     UIFontDescriptorSizeAttribute  ：設置字體尺寸
     UIFontDescriptorMatrixAttribute：設置字體形變
     */
    UIFontDescriptor *attributeFontDescriptor = [UIFontDescriptor fontDescriptorWithFontAttributes:
                                                 @{UIFontDescriptorFamilyAttribute: @"Marion",
                                                   UIFontDescriptorNameAttribute:@"Marion-Regular",
                                                   UIFontDescriptorSizeAttribute: @40.0,
                                                   UIFontDescriptorMatrixAttribute:[NSValue valueWithCGAffineTransform:CGAffineTransformMakeRotation(M_1_PI*1.5)
                                                                                    ]}];
    fnotLabel.font = [UIFont fontWithDescriptor:attributeFontDescriptor size:0.0];

其中的字體家族名和字體名可以通過以下方法獲取

NSLog(@"familyNames：%@",[UIFont familyNames]);

以上兩種方法均可以為label設置字體，但是全部是只針對英文數字，對中文無效。要想改變中文字體還需要使用后面兩種辦法

2.動態下載字體

iOS6以后蘋果就開始支持動態下載中文字體已供應用中展示個性字體的需求，由於下載的時候需要使用的名字是PostScript名稱，需要使用Mac內自帶的應用“字體冊“來獲得相應字體的PostScript名稱。如下顯示了從”字體冊“中獲取《娃娃體-繁常規體》字體的PostScript名稱的截圖

具體代碼就不一一介紹了，大家可以參考蘋果提供的有關文檔：https://developer.apple.com/library/ios/samplecode/DownloadFont/Listings/DownloadFont_ViewController_m.html#//apple_ref/doc/uid/DTS40013404-DownloadFont_ViewController_m-DontLinkElementID_6

或者也可以參考唐巧先生的博客有比較詳細的介紹：http://blog.devtang.com/blog/2013/08/11/ios-asian-font-download-introduction/

下面是我研究后的測試demo，提供給大家參考：

- (void)asynchronouslySetFontName:(NSString *)fontName
{
    UIFont* aFont = [UIFont fontWithName:fontName size:24];
    // If the font is already downloaded
    if (aFont && ([aFont.fontName compare:fontName] == NSOrderedSame || [aFont.familyName compare:fontName] == NSOrderedSame)) {
        // Go ahead and display the sample text.
        _fLabelView.text = @"歡迎查看我的博客";
        _fLabelView.font = [UIFont fontWithName:fontName size:24];
        return;
    }
    
    // Create a dictionary with the font's PostScript name.
    NSMutableDictionary *attrs = [NSMutableDictionary dictionaryWithObjectsAndKeys:fontName, kCTFontNameAttribute, nil];
    
    // Create a new font descriptor reference from the attributes dictionary.
    CTFontDescriptorRef desc = CTFontDescriptorCreateWithAttributes((__bridge CFDictionaryRef)attrs);
    
    NSMutableArray *descs = [NSMutableArray arrayWithCapacity:0];
    [descs addObject:(__bridge id)desc];
    CFRelease(desc);
    
    __block BOOL errorDuringDownload = NO;
    
    // Start processing the font descriptor..
    // This function returns immediately, but can potentially take long time to process.
    // The progress is notified via the callback block of CTFontDescriptorProgressHandler type.
    // See CTFontDescriptor.h for the list of progress states and keys for progressParameter dictionary.
    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(), ^ {
                // Show an activity indicator
                NSLog(@"Begin Matching");
            });
        } else if (state == kCTFontDescriptorMatchingDidFinish) {
            dispatch_async( dispatch_get_main_queue(), ^ {
                // Remove the activity indicator
                
                // Display the sample text for the newly downloaded font
                _fLabelView.text = @"歡迎查看我的博客";
                _fLabelView.font = [UIFont fontWithName:fontName size:24];
                
                // Log the font URL in the console
                CTFontRef fontRef = CTFontCreateWithName((__bridge CFStringRef)fontName, 0., NULL);
                CFStringRef fontURL = CTFontCopyAttribute(fontRef, kCTFontURLAttribute);
                NSLog(@"%@", (__bridge NSURL*)(fontURL));
                CFRelease(fontURL);
                CFRelease(fontRef);
                
                if (!errorDuringDownload) {
                    NSLog(@"%@ downloaded", fontName);
                }
            });
        } else if (state == kCTFontDescriptorMatchingWillBeginDownloading) {
            dispatch_async( dispatch_get_main_queue(), ^ {
                // Show a progress bar
             
                NSLog(@"Begin Downloading");
            });
        } else if (state == kCTFontDescriptorMatchingDidFinishDownloading) {
            dispatch_async( dispatch_get_main_queue(), ^ {
                // Remove the progress bar

                NSLog(@"Finish downloading");
            });
        } else if (state == kCTFontDescriptorMatchingDownloading) {
            dispatch_async( dispatch_get_main_queue(), ^ {
                // Use the progress bar to indicate the progress of the downloading
                NSLog(@"Downloading %.0f%% complete", progressValue);
            });
        } else if (state == kCTFontDescriptorMatchingDidFailWithError) {
            // An error has occurred.
            // Get the error message
            NSError *error = [(__bridge NSDictionary *)progressParameter objectForKey:(id)kCTFontDescriptorMatchingError];
            if (error != nil) {
                _errorMessage = [error description];
            } else {
                _errorMessage = @"ERROR MESSAGE IS NOT AVAILABLE!";
            }
            // Set our flag
            errorDuringDownload = YES;
            
            dispatch_async( dispatch_get_main_queue(), ^ {
                NSLog(@"Download error: %@", _errorMessage);
            });
        }
        return (bool)YES;
    });   
}

只要在相應地方調用就可以了：

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    _fLabelView = [[UITextView alloc] initWithFrame:CGRectMake(50, 100, 250, 100)];
    [self.view addSubview:_fLabelView];
    
    [self asynchronouslySetFontName:@"HanziPenSC-W3"];
    
}

下面是運行后的結果：