Question

我是目标C的新手，我正处于需要紧急创建应用程序的位置。我正在使用XCode 4.2

在应用程序的一部分中，我将检测QR码并获得NSString格式的VCard：我使用以下代码完成了该功能： -I将以下内容导入框架：

AddressBookUI.framework
AddressBook.framework

在我写的.h文件中：

#import <addressBook/AddressBook.h>
#import <AddressBookUI/AddressBookUI.h>

@interface HellowWorld : UIViewController<ABPeoplePickerNavigationControllerDelegate>{

}

-(IBAction)saveContacts;
@end

我写的.m文件中的

：

-(IBAction)saveContacts{
    NSString *vCardString = test //where the data will be comming from
    CFDataRef vCardData = (CFDataRef)[vCardString dataUsingEncoding:NSUTF8StringEncoding];  ABAddressBookRef book = ABAddressBookCreate(); 
    ABRecordRef defaultSource = ABAddressBookCopyDefaultSource(book); 
    CFArrayRef vCardPeople = ABPersonCreatePeopleInSourceWithVCardRepresentation(defaultSource, vCardData); 
    for (CFIndex index = 0; index < CFArrayGetCount(vCardPeople); index++) {     
        ABRecordRef person = CFArrayGetValueAtIndex(vCardPeople, index);     
        ABAddressBookAddRecord(book, person, NULL);     
        CFRelease(person); 
    }  
    CFRelease(vCardPeople); 
    CFRelease(defaultSource); 
    ABAddressBookSave(book, NULL); 
    CFRelease(book); 
}

我使用了这段代码，但它无效。

首先它没有编译这一行：

CFDataRef vCardData = (CFDataRef)[vCardString dataUsingEncoding:NSUTF8StringEncoding];

我不得不改变它：

CFDataRef vCardData = (__bridge CFDataRef)[vCardString dataUsingEncoding:NSUTF8StringEncoding];

并且在编译之后它在此行崩溃：

 for (CFIndex index = 0; index < CFArrayGetCount(vCardPeople); index++) {

它会出现以下绿色错误：Thread1: Program Received Signal "EXC_BAD_ACCESS"。有什么理由吗？

这也是在地址簿中保存VCard（NSString格式）的唯一方法吗？还有其他建议吗？

Answer 1

我假设您已启用ARC。

使用它时CFRetain vCardData对象会阻止崩溃吗？数据对象可能只存在直到范围结束。

或者可能更好，请使用__bridge_retained

请参阅release notes on ARC

Answer 2

将Vcard数据导入Iphone联系人列表。

添加AddressbookUi.framework

添加Addressbook.framework

包含此标题：

#include AddressBook/ABAddressBook.h>
#include AddressBook/ABRecord.h>
#include AddressBook/ABSource.h>

并调用此函数：

-(void)importVcard {

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *startPath = [paths objectAtIndex:0]; 
    NSString *filename  = @"contacts.vcf";
    NSString *filePath = [NSString stringWithFormat:@"%@/%@",startPath,filename];
    NSLog(@"File Path is %@",startPath);

    NSString *vCardString = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:nil ];

    CFDataRef vCardData = (CFDataRef)[vCardString dataUsingEncoding:NSUTF8StringEncoding];  ABAddressBookRef book = ABAddressBookCreate(); 
    ABRecordRef defaultSource = ABAddressBookCopyDefaultSource(book); 

    CFArrayRef vCardPeople = ABPersonCreatePeopleInSourceWithVCardRepresentation(defaultSource, vCardData); 

    for (CFIndex index = 0; index < CFArrayGetCount(vCardPeople); index++) {     
        ABRecordRef person = CFArrayGetValueAtIndex(vCardPeople, index);     
        ABAddressBookAddRecord(book, person, NULL);     
        CFRelease(person); 
    }  

    CFRelease(vCardPeople); 
    CFRelease(defaultSource); 
    ABAddressBookSave(book, NULL); 
    CFRelease(book); 
}

VCard读卡器不工作

2 个答案: