问题描述
@interface Connections()
{
static Connections *this;
}
@end
.m文件中的上述代码丢弃编译器错误
The above piece of code in .m file throwing compiler error
同时
关键字被删除它运作良好 - 这是显而易见的。
目的：我想要连接实例静态和私有。
key word is removed it works well - which so obvious.Purpose : I want "Connections" instance static and private.
为什么会出现这种情况，请帮忙。
Why is this behavior, please help.
推荐答案
您不能在Objective-C类中声明类级变量;相反，你需要在实现文件中隐藏它们，通常给它们 static -scope，这样它们就无法从外部访问。
You cannot declare class-level variables in Objective-C classes; instead you need to "hide" them in the implementation file, often giving them static-scope so they cannot be accessed externally.
Connections.m：
Connections.m:
#import "Connections.h"
static Connections *_sharedInstance = nil;
@implementation Connections
...
@end
如果这是一个单例，你通常会定义一个类级访问器来在第一次使用时创建单例：
And if this is a singleton, you typically define a class-level accessor to create the singleton upon first use:
+ (Connections *)sharedInstance
{
if (_sharedInstance == nil)
{
_sharedInstance = [[Connections alloc] init];
}
return _sharedInstance;
}
（你需要在.h文件中添加声明） ：
(and you'll need to add the declaration in the .h file):
+ (Connections *)sharedInstance;
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