How to access NSObject class/instance variable from view controllers?

Question

I want to pass a NSString value to a class method of a NSObject class: +(void)loadTableData:(myCompletion) compblock;. So I can only use a class variable NSString *categoryID for use in the class method. I declare it in the .h file trying to let it also be used for public access. But I tried many ways, and can only declare it like below. Other positions will give me warning.

#import <Foundation/Foundation.h>

typedef void(^myCompletion)(NSArray *);
NSString *categoryID;

@interface ThirdVCLoadTable : NSObject
+ (void)loadTableData:(myCompletion) compblock;
@end

Then the problem is I am still not able to access it in my view controller class. The error message is always: Property "categoryID" not found on object of type "ThirdVCLoadTable", no matter what I try in order to access the NSString *categoryID.

For example,

ThirdVCLoadTable *load = [[ThirdVCLoadTable alloc] init];
load.categoryID = [NSString stringWithFormat:@"%li", (long)indexPath.row + 1];

You need declare property of string in .h file.@property (nonatomic,strong)NSString *categoryID; — KKRocks, Oct 10 '16 at 05:13

score 0 · Answer 1 · answered Oct 10 '16 at 05:14

0

It's not a property of the class. Try putting

@property (copy, nonatomic) NSString * categoryID;

below @interface

answered Oct 10 '16 at 05:14

GetSwifty

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But I cannot directly use it in a **class method** in the .m file if it is a property. – Chenya Zhang Oct 10 '16 at 05:21
That's not quite how you deal with class variable in Objective-C. See: http://stackoverflow.com/questions/695980/how-do-i-declare-class-level-properties-in-objective-c#696024 – GetSwifty Oct 10 '16 at 17:49

score 0 · Answer 2 · edited May 23 '17 at 12:33

0

Declare a property in that class which you will call later from another view.

Suppose, in viewcontrollerA , in .h

@property (copy, nonatomic) NSString * StrName;

In viewcontrollerB, implement it like :

viewcontrollerA *vc = [[viewcontrollerA alloc]    initWithNib:@"viewcontrollerA" bundle:nil];
vc.StrName = @"XYZ";
[self pushViewController:vc animated:YES];

Get more help from this :

How to use NSString from NSObject class in multiple Classes (View Controllers)

Passing Data between View Controllers

edited May 23 '17 at 12:33

Community

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answered Oct 10 '16 at 05:20

Jamshed Alam

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But I want to directly use the NSString in a **class method** in the NSObject's .m file as I described in the problem above. – Chenya Zhang Oct 10 '16 at 05:22
1

You have two separate class/viewcontroller, right ? edit the question with more info. Paste codes from both class. – Jamshed Alam Oct 10 '16 at 05:32

Krutarth Patel · Answer 3 · 2016-10-10T06:43:23.423

Step 1: suppose my ClassName is Info.

Info.h file

@interface Info : NSObject
typedef void(^myCompletion)(NSArray *);

@end
@interface ThirdVCLoadTable : NSObject

@property (strong, nonatomic) NSString * categoryID;

+ (void)loadTableData:(myCompletion) compblock;

Info.m file

+ (void)loadTableData:(myCompletion) compblock {

}

if you want to access Class Method in viewControllers than you can use like

ThirdVCLoadTable* load = [[ThirdVCLoadTable alloc] init];
load.categoryID = [NSString stringWithFormat:@"%li", (long)indexPath.row + 1];

How to access NSObject class/instance variable from view controllers?

3 Answers3