如何将NSArray转换为NSMutableArray

Question

ABAddressBookRef addressBook = ABAddressBookCreate();
CFArrayRef allPeople = ABAddressBookCopyArrayOfAllPeople(addressBook);  
CFIndex nPeople = ABAddressBookGetPersonCount(addressBook);

NSMutableArray *tempPeoples=[[NSMutableArray alloc]init];

for(int i=0;i<nPeople;i++){

    ABRecordRef i1=CFArrayGetValueAtIndex(allPeople, i);
    [tempPeoples addObject:i1];

//  [peoples addObject:i1];

}// end of the for loop
peoples=[tempPeoples copy];

此代码提供异常b/c我想将NSMutableArray转换为NSArray请帮助

Answer 1

主题为"如何转换NSArray为NSMutableArray".为了得到一个NSMutableArray从NSArray,请使用类方法NSMutableArray+ arrayWithArray.

您的代码不会显示人们的声明.假设它被声明为NSMutableArray,如果您尝试将其视为一个问题,则可能会遇到问题.当您将复制消息发送到a时NSMutableArray,您将获得一个不可变对象,NSArray因此,如果您尝试将对象添加到复制对象NSMutableArray,则会出现错误.

CFArrayRef是免费的桥接NSArray,所以你可以这样简化你的代码:

CFArrayRef allPeople = ABAddressBookCopyArrayOfAllPeople(addressBook);
//NSMutableArray *tempPeoples = [NSMutableArray arrayWithArray:(NSArray*)allPeople];
// even better use the NSMutableCopying protocol on NSArray
NSMutableArray *tempPeoples = [(NSArray*)allPeople mutableCopy];
CFRelease(allPeople);
return tempPeoples; // or whatever is appropriate to your code

在上面的代码中,tempPeoples是一个自动释放的,NSMutableArray可以根据需要添加或删除对象.