在 Xcode 中，错误显示“活动”未声明

Question

您好，我是开发新手，我想知道你们中的任何一个专业人士是否知道如何解决这个问题。 我的代码如下：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

在 [activities count] 和 [activities release] 旁边，它指出错误“'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

编辑

您的财产声明中有错字。

actvities应该是activities ，带有i 。

在编码和阅读自己的代码时，您应该更加小心......

编辑结束

显然，您还没有声明activities变量。 这就是为什么 XCode 说它是未申报的……

我想它应该是一个 NSArray... 您需要在 class 接口（header 文件）中声明变量。

就像是：

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

然后，在您的实现中，您需要分配它，例如在 init 方法中：

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

    return self;
}

并且不要忘记在 dealloc 方法中释放它：

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

Answer 2

去掉 viewDidLoad 方法前后的/*和*/代码，并在 your.h 文件中声明一个名为 activity 的 NSArray。

NSArray *activities;

编辑----正如麦克梅德所说，只需修复拼写错误！