随机显示一个按钮上的字母,麻烦我的objective-c代码

Question

我正在尝试创建一个随机显示按钮上的字母的程序.我希望能够单击按钮(开始),程序将生成一个随机字母作为按钮的标题(letter1).

每次运行此程序时,它立即崩溃:

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

-(IBAction)start:(id)sender{

int randomNumber = rand() % 25;

switch (randomNumber){
    case 0:
        [letter1 setTitle:@"A" forState:UIControlStateNormal];
        break;
    case 1:
        [letter1 setTitle:@"B" forState:UIControlStateNormal];
        break;
    case 2:
        [letter1 setTitle:@"C" forState:UIControlStateNormal];
        break;
    case 3:
        [letter1 setTitle:@"D" forState:UIControlStateNormal];
        break;
    case 4:
        [letter1 setTitle:@"E" forState:UIControlStateNormal];
        break;
    case 5:
        [letter1 setTitle:@"F" forState:UIControlStateNormal];
        break;
    case 6:
        [letter1 setTitle:@"G" forState:UIControlStateNormal];
        break;
    case 7:
        [letter1 setTitle:@"H" forState:UIControlStateNormal];
        break;
    case 8:
        [letter1 setTitle:@"I" forState:UIControlStateNormal];
        break;
    case 9:
        [letter1 setTitle:@"J" forState:UIControlStateNormal];
        break;
    case 10:
        [letter1 setTitle:@"K" forState:UIControlStateNormal];
        break;
    case 11:
        [letter1 setTitle:@"L" forState:UIControlStateNormal];
        break;
    case 12:
        [letter1 setTitle:@"M" forState:UIControlStateNormal];
        break;
    case 13:
        [letter1 setTitle:@"N" forState:UIControlStateNormal];
        break;
    case 14:
        [letter1 setTitle:@"O" forState:UIControlStateNormal];
        break;
    case 15:
        [letter1 setTitle:@"P" forState:UIControlStateNormal];
        break;
    case 16:
        [letter1 setTitle:@"Q" forState:UIControlStateNormal];
        break;
    case 17:
        [letter1 setTitle:@"R" forState:UIControlStateNormal];
        break;
    case 18:
        [letter1 setTitle:@"S" forState:UIControlStateNormal];
        break;
    case 19:
        [letter1 setTitle:@"T" forState:UIControlStateNormal];
        break;
    case 20:
        [letter1 setTitle:@"U" forState:UIControlStateNormal];
        break;
    case 21:
        [letter1 setTitle:@"V" forState:UIControlStateNormal];
        break;
    case 22:
        [letter1 setTitle:@"W" forState:UIControlStateNormal];
        break;
    case 23:
        [letter1 setTitle:@"X" forState:UIControlStateNormal];
        break;
    case 24:
        [letter1 setTitle:@"Y" forState:UIControlStateNormal];
        break;
    case 25:
        [letter1 setTitle:@"Z" forState:UIControlStateNormal];
        break;
    default:
        [letter1 setTitle:@"&" forState:UIControlStateNormal];
        break;

   }



}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

 - (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

任何帮助,将不胜感激!!!!

Answer 1

您没有提供足够的信息来解释崩溃.但是你可以通过消除switch语句来大大缩短你的代码

-(IBAction)start:(id)sender
{
    int randomValue = 'A' + arc4random_uniform(('Z' + 1) - 'A');
    [letter1 setTitle: [NSString stringWithFormat:@"%c", randomValue]) forState:UIControlStateNormal];
}