问题描述
好的,我正在努力解决这个问题。我已经搜索了过去的一小时,我不知道我做错了什么。我正在尝试获取发送者的currentTitle,然后将其转换为整数,以便我可以在列表调用中使用它。
Okay, I am having a hard time with this. I've searched for the past hour on it and I don't get what I am doing wrong. I'm trying to take the currentTitle of a sender, then convert it to an integer so I can use it in a call to list.
NSString *str = [sender currentTitle];
NSInteger *nt = [str integerValue]; // this is where the error appears //
NSString *nextScreen = [NSString stringWithFormat:@"Screen_%@.jpg", [screenList objectAtIndex:nt]];
我认为这是 [str integerValue]
位没有正确使用,但我找不到一个有效的例子。
I assume it's something with the [str integerValue]
bit not being properly used, but I can't find an example that works.
谢谢!
推荐答案
让我们分析错误信息:
初始化( NSInteger nt
)在没有强制转换的情况下从整数( [str integerValue]
)生成指针( *
)。 / em>
Initialization (NSInteger nt
) makes pointer (*
) from integer ([str integerValue]
) without a cast.
这意味着您正在尝试分配非指针类型的变量( [str integerValue]
,它返回 NSInteger
)到 指针类型的变量。 ( NSInteger *
)。
This means that you are trying to assign a variable of non-pointer type ([str integerValue]
, which returns an NSInteger
) to a variable of pointer type. (NSInteger *
).
摆脱 *
NSInteger
后你应该没问题:
Get rid of the *
after NSInteger
and you should be okay:
NSString *str = [sender currentTitle];
NSInteger nt = [str integerValue]; // this is where the error appears //
NSString *nextScreen = [NSString stringWithFormat:@"Screen_%@.jpg", [screenList objectAtIndex:nt]];
是机器相关的类型包装器积分数据类型,定义如下:
NSInteger
is a type wrapper for the machine-dependent integral data type, which is defined like so:
#if __LP64__ || (TARGET_OS_EMBEDDED && !TARGET_OS_IPHONE) || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
typedef long NSInteger;
typedef unsigned long NSUInteger;
#else
typedef int NSInteger;
typedef unsigned int NSUInteger;
#endif
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