ios 在 iPhone 应用程序中分配 NSInteger 属性
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Assigning NSInteger property in iPhone App
提问by Nazia Jan
I have a table in SQLite I want to insert data in that table. The table has responses_id, participant_id, answer_text, answer_option_update_date_time. responses_id and participant_id are integers. When I am assigning any thing to participant_id it gives an error, object can not set to property.
我在 SQLite 中有一个表，我想在该表中插入数据。该表有responses_id、participant_id、answer_text、answer_option_update_date_time。响应 ID 和参与者 ID 是整数。当我将任何东西分配给参与者_id 时，它会出现错误，对象无法设置为属性。
@interface Coffee : NSObject {
NSInteger coffeeID;
NSInteger participant_Id;
NSString*question_Id;
NSString*answer_option;
NSString*answer_text;
NSString*update_date_time;
//Intrnal variables to keep track of the state of the object.
}
@property (nonatomic, readonly) NSInteger coffeeID;
@property (nonatomic, retain) NSInteger participant_Id;
@property (nonatomic, copy) NSString *question_Id;
@property (nonatomic, copy) NSString *answer_option;
@property (nonatomic, copy) NSString *answer_text;
@property (nonatomic, copy) NSString *update_date_time;
- (void)save_Local {
CereniaAppDelegate *appDelegate = (CereniaAppDelegate *)[[UIApplication sharedApplication] delegate];
Coffee *coffeeObj = [[Coffee alloc] initWithPrimaryKey:0];
coffeeObj.participant_Id=mynumber;
NSString*question="1";
coffeeObj.question_Id=question;
coffeeObj.answer_option=selectionAnswerOption;
coffeeObj.answer_text=professionTextField.text;
NSDate* date = [NSDate date];
NSDateFormatter* formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy-MM-dd HH:MM:SS"];
NSString* str = [formatter stringFromDate:date];
UPDATE_DATE_TIME=str;
coffeeObj.update_date_time=UPDATE_DATE_TIME;
//Add the object
[appDelegate addCoffee:coffeeObj];
}
When I am assigning a value to participant_id it gives an error.
当我为participant_id 赋值时，它给出了一个错误。
回答by mttrb
NSIntegeris not a class, it is a basic type like an intor long. On iOS NSIntegeris typedefed to an int, on OS X it is typedefed to a long. Therefore, you shouldn't try to retainan NSInteger. You should change your property declaration to:
NSInteger不是一个类，它是一个像intor一样的基本类型long。在 iOS 上NSInteger被typedef编为int，在 OS X 上被typedef编为long。因此，您不应该尝试retain使用NSInteger. 您应该将您的财产声明更改为：
@property (nonatomic, assign) NSInteger participant_Id;
The same goes for your coffeeIDproperty.
您的coffeeID财产也是如此。
