标签: cfstring

根据文档 CFDictionaryCreate用于实例化CFDictionary swift.

func CFDictionaryCreate(_ allocator: CFAllocator!,
                  _ keys: UnsafeMutablePointer<UnsafePointer<Void>>,
                  _ values: UnsafeMutablePointer<UnsafePointer<Void>>,
                  _ numValues: CFIndex,
                  _ keyCallBacks: UnsafePointer<CFDictionaryKeyCallBacks>,
                  _ valueCallBacks: UnsafePointer<CFDictionaryValueCallBacks>) -> CFDictionary!

我怎样才能创建keys和values参数？到目前为止,我已尝试使用swift的String类型,希望它会自动转换为适当的类型:

import Foundation

var keys : [String] = ["key1", "key2"]
var values : [String] = ["value1", "value2"]
var keyCallbacks = kCFTypeDictionaryKeyCallBacks
var valueCallbacks = kCFTypeDictionaryValueCallBacks
var dict : CFDictionary = CFDictionaryCreate(kCFAllocatorDefault,
    &keys, &values, 2, &keyCallbacks, &valueCallbacks)

不幸的是我收到一个错误,说String不是keys和values数组元素的正确类型:

main.swift:41:2: error: 'String' is …

我的应用程序正在处理联系人数据.

电话标签检索如下

let locPhoneLabel : NSString = (ABMultiValueCopyLabelAtIndex(phones, numberIndex) != nil) ? ABMultiValueCopyLabelAtIndex(phones, numberIndex).takeUnretainedValue() as CFStringRef : ""

let phoneLabel:Unmanaged<CFString> = ABAddressBookCopyLocalizedLabel(locPhoneLabel)

我不知道如何将phoneLabel转换为NSString？

所以我在一个方法中调用它:

-(id)initWithContentURL:(NSString *)url {
if (self = [super init]) {
    NSLog(@"xSheetMusicViewController - %@",url);
    // Casting an NSString object pointer to a CFStringRef:
    CFStringRef cfString = (CFStringRef)url;        
    CFURLRef pdfURL = CFBundleCopyResourceURL(CFBundleGetMainBundle(), cfString, NULL, NULL);
    pdf = CGPDFDocumentCreateWithURL((CFURLRef)pdfURL);
    }
    return self;
}

哪一个在NSLog的标记处发生了崩溃:

CFURLRef pdfURL = CFBundleCopyResourceURL(CFBundleGetMainBundle(), cfString, NULL, NULL);

我从未见过这个奇妙的小错误.这是崩溃日志:

SheetMuse[83550:b603] -[NSURL _fastCharacterContents]: unrecognized selector sent to instance 0x4ec35f0
2011-09-22 17:36:22.921 SheetMuse[83550:b603] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSURL _fastCharacterContents]: unrecognized selector sent to instance 0x4ec35f0'
*** Call …

跨平台 C++ 头文件。为每个平台创建单独的 C++ 文件：windows、linux、mac。处理枚举窗口的平台特定实现。

在 mac 端：我填充了一个 CFStringRef。头文件定义了一个 QString 对象。我需要将 CFStringRef 的内容传递给 QString。

如何做到这一点？

我使用此代码获取ABPerson的姓氏

CFStringRef lastNameRef = ABRecordCopyValue((ABRecordRef)personRecordRef, kABPersonLastNameProperty);
NSString *friendLastName = (NSString*)lastNameRef;
CFRelease(lastNameRef);

当姓氏值不等于NULL时它工作正常但当此值为NULL时,应用程序在第三行崩溃,因为我尝试释放NULL

问题是女巫是在这种情况下释放CFString而不会导致应用程序崩溃的最佳方式

我正在使用Apple提供的API从AddressBook中读取记录.

我仍在考虑内存管理,所以CFStrings此刻让我感到困惑.

这就是我获取属性的方式:

//Get Basic properties
NSString* firstName = (NSString *)ABRecordCopyValue(person, kABPersonFirstNameProperty);
NSString* lastName = (NSString *)ABRecordCopyValue(person, kABPersonLastNameProperty);
NSNumber* record = [NSNumber numberWithInt:ABRecordGetRecordID(person)];

//Build Full Name
NSString* fullName=[self fullNameWith:firstName and:lastName];

//Get Phone number and Label
ABMultiValueRef phone = ABRecordCopyValue(person, property);
    //Turn identifier into index
CFIndex index = ABMultiValueGetIndexForIdentifier(phone, identifier);
    //Get the value and the label using the index
NSString *value =(NSString *)ABMultiValueCopyValueAtIndex(phone, index);
CFStringRef label = ABMultiValueCopyLabelAtIndex(phone, index);
    //Get the localized value of hte label
NSString * localizedLabel …