componentsJoinedByString给了我EXC_BAD_ACCESS [英] componentsJoinedByString gives me EXC_BAD_ACCESS

问题描述

我正在尝试将NSMutableArray转换为字符串。

声明我的NSMutableArray ...

I have an NSMutableArray i am trying to convert into a string.
Declaring my NSMutableArray...

    NSMutableArray *listData;  

然后在一个方法中...

And later inside a method...

NSString *foo = [listData componentsJoinedByString:@"|"];  
NSLog(@"%@",foo);  

无论我尝试什么，我都不断获得EXC_BAD_ACCESS。

确保数组中的每个元素都是NSString我也尝试过此方法...

It seems no matter what i try i keep getting EXC_BAD_ACCESS.
To make sure each element in my array was an NSString i also tried this...

NSMutableArray *mArray = [[NSMutableArray alloc] init];  
for (id ln in listData) {  
    NSString *boo = [NSString stringWithFormat: @"%@",ln];  
    [mArray addObject:boo];  
}  
NSString *foo = [mArray componentsJoinedByString:@"|"];  
NSLog(@"%@",foo);  

我可以通过在类内的同一方法或其他方法中添加/删除对象来操纵NSMutableArray。但是，当我尝试 componentsJoinedByString时，错误弹出。有没有人有任何建议或其他方法可以将这个数组合并为一个NSString？

I can manipulate my NSMutableArray by adding/deleting objects in the same method or other methods inside my class. But when i try "componentsJoinedByString" the error pops up. Does anyone have any advice or another way i can combine this array into a single NSString?

推荐答案

在您提供的代码中，永远不会有 NSMutableArray 表示 listData 。在代码中的某个时候，您需要创建一个代码，并大概填充它。

In the code you've given, there will never be an NSMutableArray for listData. At some point in your code, you'll need to create one, and presumably populate it.

编辑
好​​的，所以您可能会在这里遇到内存管理问题，因此让我们更加清楚：

Edit Okay, so you may get into memory management problems here, so let's be a bit clearer:

您正在为实例变量合成getter和setter，因此使用它们来访问它是一个好习惯，它们将适当地保留和释放。

You're synthesizing getters and setters for the instance variable, so it's good practice to use those to access it, they'll take care of retain and releasing appropriately.

要设置 listData ，您只需使用

self.listData = [listManage getList:[[NSUserDefaults standardUserDefaults] stringForKey:@"list_name"] list:@"LIST"]; 

或

[self setListData:[listManage getList:[[NSUserDefaults standardUserDefaults] stringForKey:@"list_name"] list:@"LIST"]];

如果您愿意。

这篇关于componentsJoinedByString给了我EXC_BAD_ACCESS的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！