在 Xcode 中，错误显示“活动”未声明

Question

Hello I'm new to developing and I was wondering if any of you pros would know how to fix this issue. My code is Below: InstaTwitViewController.m:

#import "InstaTwitViewController.h"

@implementation InstaTwitViewController




/*
// The designated initializer. Override to perform setup that is required before the view is loaded.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}
*/

/*
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
}
*/


/*
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];
        activities = [[NSArray alloc] initWithObjects:@"sleeping",
 @"eating", @"working", @"thinking", @"crying", @"begging",
 @"leaving", @"shopping", @"hello worlding", nil];
        feelings = [[NSArray alloc] initWithObjects: @"awesome",
 @"sad", @"happy", @"ambivalent", @"nauseous", @"psyched",
 @"confused", @"hopeful", @"anxious", nil];
}
*/


/*
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
*/

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}


- (void)dealloc {
    [activities release];
    [feelings release];
    [super dealloc];
}
- (NSInteger)numberOfComponentsInPickerView: (UIPickerView *)
pickerView {
    return 2;
}
- (NSInteger)pickerView:(UIPickerView *)
pickerViewnumberOfRowsInComponent :(NSInteger)component {
    if (component == 0) {
        return [activities count];
    }
    else {
        return [feelings count];
    }
}
@end

Next to [activities count] and [activities release] it states an error "'activities' undeclared"

InstaTwitViewController.h:

//
//  InstaTwitViewController.h
//  InstaTwit
//
//  Created by John Bridge on 5/2/11.
//  Copyright 2011 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface InstaTwitViewController : UIViewController 
<UIPickerViewDataSource, UIPickerViewDelegate> {
    NSArray* actvities;
    NSArray* feelings;
}
@end

Answer 1

EDIT

You have a typo in your property declaration.

actvities should be activities , with an i .

You should be more careful while coding, and reading your own code...

EDIT END

Apparently, you haven't declared the activities variable. That's why XCode says it's undeclared...

I guess it should be an NSArray... You need to declare the variable in your class interface (the header file).

Something like:

@interface InstaTwitViewController: UIViewController
{
    NSArray * activities;
}
@end

Then, in your implementation, you need to allocate it, for instance in the init method:

- ( id )initWithNibName: ( NSString * )nibNameOrNil bundle: ( NSBundle * )nibBundleOrNil 
{
    if( ( self = [ super initWithNibName: nibNameOrNil bundle: nibBundleOrNil ] ) )
    {
        activities = [ NSArray new ];
    }

    return self;
}

And don't forget to release it in the dealloc method:

- ( void )dealloc
{
    [ activities release ];
    [ super dealloc ];
}

Answer 2

Remove the /* and */ code before and after the viewDidLoad method, and declare an NSArray called activities in your.h file.

NSArray *activities;

EDIT---- As MacMade said, just fix the spelling mistake!