分配對象再分配問題

Question

在[searchDict發行版]中發生崩潰。如果我切換最後兩行的順序，它仍然會在最後一行（現在是[searchArray release]）上崩潰。我對Objective C很陌生，我想我沒有得到alloc/release權限......幫助？ :)

NSMutableDictionary *searchDict = [[NSMutableDictionary alloc] init]; 
NSMutableArray *searchArray = [[NSMutableArray alloc] init]; 

for(int i = 0; i < 2; i++) { // Run two times ("Favorites" and "All") 
    searchDict = [listOfItems objectAtIndex:i]; 
    searchArray = [searchDict objectForKey:@"Entries"]; 

    for (NSString *sTemp in searchArray) { 
     NSRange titleResultsRange = [sTemp rangeOfString:searchText options:NSCaseInsensitiveSearch]; 
     if (titleResultsRange.length > 0) 
      [listOfItemsDynamic addObject:sTemp]; 
    } 
} 

[searchArray release]; 
[searchDict release]; 

Answer 1

您分配空間，並將其分配給變量：

NSMutableDictionary *searchDict = [[NSMutableDictionary alloc] init]; 
NSMutableArray *searchArray = [[NSMutableArray alloc] init]; 

但你分配非本地數據分配給他們：

searchDict = [listOfItems objectAtIndex:i]; 
searchArray = [searchDict objectForKey:@"Entries"]; 

所以基本上，你不不需要分配和釋放。相反，做這樣的事情：

NSMutableDictionary *searchDict; // Just declartion, no allocation/init 
NSMutableArray *searchArray;  // Just declartion, no allocation/init 

for(int i = 0; i < 2; i++) { // Run two times ("Favorites" and "All") 
    searchDict = [listOfItems objectAtIndex:i]; 
    searchArray = [searchDict objectForKey:@"Entries"]; 

    for (NSString *sTemp in searchArray) { 
     NSRange titleResultsRange = [sTemp rangeOfString:searchText options:NSCaseInsensitiveSearch]; 
     if (titleResultsRange.length > 0) 
      [listOfItemsDynamic addObject:sTemp]; 
    } 
} 

// No release needed here 

如果你熟悉C，它類似於：

char *pChar; 
pChar = malloc(15); // allocate memory and assign to pChar 
pChar = "Hello"; // assign new address to pChar 
free(pChar); // Error here ;)