Question

我使用NSString追加字符串，但是当我发布“cacheStr”NSString时，iphone模拟器崩溃了。我应该把发布代码放在哪里？

init代码：我使用三个NSString来附加dataArray的内容。



NSMutableArray *dataArray = [[NSMutableArray alloc] init];
NSString *cacheStr = [[NSString alloc] init];
NSString *tmpStr = [[NSString alloc] init];
NSString *notiyStr = [[NSString alloc] initWithFormat:@"This is a test message!"];
dataArray = [NSArray arrayWithObjects:
                      @"currency1.png",
                      @"currency2.png",
                      @"currency3.png",
                      @"currency4.png",
                      @"currency5.png",
                      @"xxxxxx",
                      @"currency1.png",
                      @"currency2.png",
                      @"currency3.png",
                      @"currency4.png",
                      @"currency5.png",
                      @"xxxxxx",
                      nil];

NSMutableArray *dataArray = [[NSMutableArray alloc] init];
NSString *cacheStr = [[NSString alloc] init];
NSString *tmpStr = [[NSString alloc] init];
NSString *notiyStr = [[NSString alloc] initWithFormat:@"This is a test message!"];
dataArray = [NSArray arrayWithObjects:
                      @"currency1.png",
                      @"currency2.png",
                      @"currency3.png",
                      @"currency4.png",
                      @"currency5.png",
                      @"xxxxxx",
                      @"currency1.png",
                      @"currency2.png",
                      @"currency3.png",
                      @"currency4.png",
                      @"currency5.png",
                      @"xxxxxx",
                      nil];



append string code : use for loop to append strings.



int isFailed = 0;
int countOfDataArray = [dataArray count];
if (!isFailed) {
    for (int i=0; i < countOfDataArray; i++) {
        if ([[dataArray objectAtIndex:i] isEqualToString:@"xxxxxx"]) {
            tmpStr = [cacheStr stringByAppendingFormat:@"%@\n", [dataArray objectAtIndex:i]];
        }
        else {
            tmpStr = [cacheStr stringByAppendingFormat:@"value %d : %@\n", i+1, [dataArray objectAtIndex:i]];
        }
        cacheStr = [tmpStr copy];
        [tmpStr release];
    }
}
tmpStr = [notiyStr stringByAppendingString:cacheStr];




release code : when I add [cacheStr release], the simulator will crash...



append string code : use for loop to append strings.

谢谢！

Answer 1

声明像这样的NSString更简单
NSString *tmpStr = @"This is a test message!";
当你不使用alloc

时，不需要释放它

Answer 2

这个

NSMutableArray *dataArray = [[NSMutableArray alloc] init];
dataArray = [NSArray arrayWithObjects:
                  @"currency1.png",
                  @"currency2.png",
                  @"currency3.png",
                  @"currency4.png",
                  @"currency5.png",
                  @"xxxxxx",
                  @"currency1.png",
                  @"currency2.png",
                  @"currency3.png",
                  @"currency4.png",
                  @"currency5.png",
                  @"xxxxxx",
                  nil];

很奇怪！您正在分配一个可变数组，并将指向该数组的指针分配给您不拥有的数组。当您尝试使用它时，它可能已经（自动）发布了。因此int countOfDataArray = [dataArray count];会导致countOfDataArray为零。因此永远不会设置cacheStr。仍然不应该在释放cacheStr时崩溃。

将其更改为：

NSMutableArray *dataArray = [[NSMutableArray alloc] initWithObjects: @"currency1.png",
                  @"currency2.png",
                  @"currency3.png",
                  @"currency4.png",
                  @"currency5.png",
                  @"xxxxxx",
                  @"currency1.png",
                  @"currency2.png",
                  @"currency3.png",
                  @"currency4.png",
                  @"currency5.png",
                  @"xxxxxx",
                  nil];

你应该没事。

Answer 3

不要使用[NSString alloc] init。使用NSString值= @＆＃34;消息＆＃34 ;;无需释放它。

发布时NSString崩溃

3 个答案: