问题重新分配分配的对象

Posted 2023-03-06

【中文标题】问题重新分配分配的对象

【英文标题】：Problem realeasing allocated objects

【发布时间】：2011-08-13 15:12:29

【问题描述】：

崩溃发生在 [searchDict 版本]。如果我切换两个最新行的顺序，它仍然会在最新行（现在 [searchArray 版本]）上崩溃。我对Objective C很陌生，我想我没有正确分配/释放...帮助？ :)

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];

【参考方案1】：

您分配空间并将其分配给变量：

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

然后你将非本地分配的数据分配给它们：

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

所以基本上，你不需要分配和释放。而是做这样的事情：

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，它类似于：

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