Question

我为此疯狂。我试图从.txt文档中移植一个数组。但也永远不要重复输出。如果行为0，请执行alert或smth

我目前有这个代码，我无法弄清楚如何计算并从数组中删除呈现的对象。检查了很多帖子并尝试但没有成功..

// declare randomStory as int
int randomStory;

// declare storyString as string
NSString *storyString;

// create variables for text file

// get chronices from text file name
NSString *title = @"chronicles";
// attribute name
NSString *type = @"txt";
// seperation
NSString *separation = @"____________________________________________";
// encoding and variable
NSString *fileText = [NSString stringWithContentsOfFile:[[NSBundle mainBundle] pathForResource:title ofType:type] encoding:NSUTF8StringEncoding error:nil];

// create array with seperated text by \n
NSMutableArray *storyArray = [[NSMutableArray alloc]initWithArray:[fileText componentsSeparatedByString:separation]];

// randomize one text from the text file
randomStory = arc4random()%[storyArray count];

storyString = [storyArray objectAtIndex: randomStory];

// output in storyLabel textView
_storyLabel.text
= storyString;

EDIT:

上帝的缘故，无法粘贴代码。以下是它的外观和SIGABRT错误。 http://pastebin.com/21hvrzwU

Answer 1

问题是（如果OP代码全部存在于单个方法中），每次调用该方法都会从文件重建一个新数组。最好以这种方式进行重组：

将文件读取到它自己的方法“
构建一个也只运行一次的NSArray shuffler
使用混洗数组但是你需要它在循环中

- (NSArray *)arrayFromFile {
    NSString *title = @"chronicles";
    NSString *type = @"txt";
    NSString *separation = @"____________________________________________";
    NSString *fileText = [NSString stringWithContentsOfFile:[[NSBundle mainBundle] pathForResource:title ofType:type] encoding:NSUTF8StringEncoding error:nil];
    return [fileText componentsSeparatedByString:separation];
}

- (NSArray *)shuffledArray:(NSArray *)array {
    NSMutableArray *mutable = [array mutableCopy];
    NSMutableArray *result = [@[] mutableCopy];
    while ([mutable count]) {
        NSInteger index = arc4random()%[mutable count];
        [result addObject:mutable[index]];
        [mutable removeObjectAtIndex:index];
    }
    return result;
}

// not sure the context here, but ....
NSArray *array = [self arrayFromFile];
NSArray *shuffled = [self shuffledArray:array];
for (NSString *string in shuffled) {
    // string will be random here
}

修改

现在，在更多上下文的情况下，当按下按钮时，如何让用户在UILabel中看到随机字符串：

将数组属性和当前索引添加到包含按钮和标签的视图控制器：

@property(strong,nonatomic) NSArray *shuffledStrings; @property(assign,nonatomic) NSInteger currentIndex;

创建一个＆＃34;懒惰＆＃34;数组的初始值设定项，使用上面建议的代码：

- (NSArray *)shuffledStrings { if (!_shuffledStrings) { NSArray *array = [self arrayFromFile]; _shuffledStrings = [self shuffledArray:array]; } return _shuffledStrings; }

OP没有定义当文件中的字符串全部呈现时应该发生什么。使用上面的工具，我们可以重新使用相同的洗牌列表，或者再次洗牌并重新开始......

- (IBAction)buttonPressed:(id)sender { if (self.currentIndex == [self.shuffledStrings count]) { // just start again self.currentIndex = 0; // OR, reshuffle and start again // self.shuffledStrings = [self shuffledArray:self.shuffledStrings]; // self.currentIndex = 0; } NSString *nextString = self.shuffledStrings[self.currentIndex++]; // assuming you have a myLabel outlet self.myLabel.text = nextString; }

Obj-c Shuffle Array没有重复

1 个答案: