Question

我在网上寻找帮助时遇到了一些麻烦，这让我觉得我想做的事情可能无法实现，但无论如何我都会问！我是obj-c的新手，我只是为了一点乐趣而开发......

我试图根据从另一个数组中随机抽取的字符串来调用数组。我有一个名为pickerArray的NSArray来保存字符串：oneArray，twoArray作为示例。

我还有NSString（pickerString），NSArray（oneArray）和NSArray（twoArray）。

我可以随机选择字符串，我不能做的就是将这种刺痛的值用作'代码'

randomNumber = arc4random()%[pickerString count];

pickerString应该在代码中读取为oneArray或twoArray，具体取决于字符串
被选中，即

randomNumber = arc4random()%[oneArray count];

或：

randomNumber = arc4random()%[twoArray count];

取决于所挑选的字符串。

编辑：我当前的代码是：

@implementation FirstViewController{

IBOutlet UITextView *doThis;
}
- (IBAction)takeATurn:(id)sender {
int pickerNumber;
int randomNumber;
NSString *pickerString;
NSString *textString;
NSArray *pickerArray;
NSArray *oneArray;
NSArray *twoArray;

pickerArray = [NSArray arrayWithObjects:
               @"oneArray",
               @"twoArray",

               nil];

oneArray = [NSArray arrayWithObjects:
               @"example text to display",
               @"expmple text to display 2",

               nil];
twoArray = [NSArray arrayWithObjects:
               @"example text to display in array two",
               @"expmple text to display in array two 2",

               nil];

pickerNumber = arc4random()%[pickerArray count];

pickerString = [pickerArray objectAtIndex:pickerNumber];

randomNumber = arc4random()%[NSArray(pickerString) count];
     //does not compile - should read [oneArray count]; (or twoArray in place of oneArray

textString = [NSArray(pickerString) objectAtIndex:randomNumber];
     //same as above.


doThis.text = textString;
}

感谢您的帮助。麦克

Answer 1

这是一个键值编码问题：

NSArray *arrayToUse = [self valueForKey:pickerString];

这将返回由pickerString命名的属性。

要按照您希望的方式工作，请将数组移动到实例属性而不是局部变量。

编辑：

这将是这样的：

@interface FirstViewController ()
@property (nonatomic, readwrite, weak) IBOutlet UITextView *doThis;

@property (nonatomic, readwrite, strong) NSArray *pickerArray;
@property (nonatomic, readwrite, strong) NSArray *oneArray;
@property (nonatomic, readwrite, strong) NSArray *twoArray;
@end

@implementation FirstViewController

// You can put this wherever you initialize the object (init, viewDidLoad, awakeFromNib, etc.)
// viewWillAppear just tends to work for a wide variety of design choices.
- (void)viewWillAppear:(BOOL)animated {
  self.pickerArray = @[
                       @"oneArray",
                       @"twoArray",
                     ];

  self.oneArray = @[
                    @"example text to display",
                    @"expmple text to display 2",
                  ];

  self.twoArray = @[
                    @"example text to display in array two",
                    @"expmple text to display in array two 2",
                  ];
}

- (IBAction)takeATurn:(id)sender {
  int pickerNumber = arc4random_uniform([self.pickerArray count]);
  NSString *pickerString = pickerArray[pickerNumber];
  NSArray *array = [self valueForKey:pickerString];
  int randomNumber = arc4random_uniform(array count]);
  NSString *textString = array[randomNumber];
  self.doThis.text = textString;
}

Answer 2

您可以将代码块放入方法中并尝试解决方案：

https://stackoverflow.com/a/4446914/584663

在目标c中使用变量值作为动态代码？

2 个答案: