CGFontCreateWithDataProvider在飞行模式下挂起

Question

当我CGFontCreateWithDataProvider 在飞机模式下拨打电话时,我的应用会冻结.不是飞机模式,它工作正常.字体存储在设备上,不应该发生网络访问.

在调用此方法加载本地字体文件时:

[self registerIconFontWithURL:[[NSBundle mainBundle] URLForResource:@"FontAwesome" withExtension:@"otf"]];

的值url在下面的方法是: 文件:///var/mobile/Applications/48D3DA14-235B-4450-A081-7A6BA6116667/Blah.app/FontAwesome.otf

+ (void)registerIconFontWithURL:(NSURL *)url
{
    NSAssert([[NSFileManager defaultManager] fileExistsAtPath:[url path]], @"Font file doesn't exist");
    CGDataProviderRef fontDataProvider = CGDataProviderCreateWithURL((__bridge CFURLRef)url);

//******Freezes after the next line******
    CGFontRef newFont = CGFontCreateWithDataProvider(fontDataProvider);
//******FROZEN******

    CGDataProviderRelease(fontDataProvider);
    CFErrorRef error;
    CTFontManagerRegisterGraphicsFont(newFont, &error);
    CGFontRelease(newFont);
}

iOS 7.1.x,iPhone 5.

我不知道为什么会发生这种情况并且无法找到任何帮助.有没有人知道为什么会发生这种情况？

提前致谢!

Answer 1

经过一番搜索,我找到了答案.

根据以下错误报告:https://alpha.app.net/jaredsinclair/post/18555292

如果没有网络连接,如果在appDidFinishLaunchingWithOptions期间调用它,则CGFontCreateWithDataProvider()会挂起信号量陷阱.在下一个运行循环中调用它无需挂起即可.

如同一篇文章中所述,致电

[UIFont familyNames]

之前 CGFontCreateWithDataProvider()

解决了这个问题.我的代码现在看起来像这样,并按预期工作:

+ (void)registerIconFontWithURL:(NSURL *)url
{
    NSAssert([[NSFileManager defaultManager] fileExistsAtPath:[url path]], @"Font file doesn't exist");
    CGDataProviderRef fontDataProvider = CGDataProviderCreateWithURL((__bridge CFURLRef)url);

    //THE NEXT LINE IS RELEVANT PART
    [UIFont familyNames];

    CGFontRef newFont = CGFontCreateWithDataProvider(fontDataProvider);
    CGDataProviderRelease(fontDataProvider);
    CFErrorRef error;
    CTFontManagerRegisterGraphicsFont(newFont, &error);
    CGFontRelease(newFont);
}