如何使用每 N 秒更改 NSString 的值？

发布于 2024-12-14 03:18:32 字数 755 浏览 2 评论 0原文

我有这段代码每五秒更改 NSString 中的数字。

我将如何保持数字循环运行？现在它从 1 运行到 19 ，并在最后一个 (19) 处停止，并在行上显示 SIGABRT： label.text = ...

如何从显示的第一个数字 (0) 开始，在第一个计时器触发之前？

这是代码：

-(IBAction) rotate3

{


    NSString *number = [self.dayArray description];

    NSArray *array = [[NSArray alloc] initWithObjects: @"0", @"1", @"2",..., @"19",nil];

    number =  @"0" ;
    numberCount++ ;


    self.dayArray = array;
    [array release];


    label.text = [NSString stringWithFormat:@"Day: %@ ", [dayArray objectAtIndex   :numberCount ]];


}

//and the timer

- (void)viewDidLoad

{

    timer=[NSTimer scheduledTimerWithTimeInterval:5.0 target:self selector:@selector(rotate3 )userInfo:nil repeats:YES];

}

原文

I have this code to change the number in the NSString every five seconds.

How will I keep the numbers running in a loop? It now runs from 1 to 19 ,and stops at the last one (19) with a SIGABRT on the line: label.text = ...

How can I start with the first number displayed (0), before the first timer fires?

Here is the code:

-(IBAction) rotate3

{


    NSString *number = [self.dayArray description];

    NSArray *array = [[NSArray alloc] initWithObjects: @"0", @"1", @"2",..., @"19",nil];

    number =  @"0" ;
    numberCount++ ;


    self.dayArray = array;
    [array release];


    label.text = [NSString stringWithFormat:@"Day: %@ ", [dayArray objectAtIndex   :numberCount ]];


}

//and the timer

- (void)viewDidLoad

{

    timer=[NSTimer scheduledTimerWithTimeInterval:5.0 target:self selector:@selector(rotate3 )userInfo:nil repeats:YES];

}

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小伙你站住 2024-12-21 03:18:32

这是我的答案：

1）我认为，在最后一个（19），numberCount是20（numberCount++；）。
2）只需在调度定时器之前设置该值即可。

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思慕 2024-12-21 03:18:32

将其添加到您的界面中的 .h 文件中（也就是说，如果它尚不存在）

{
    NSInteger numberCount
}

然后在您的 viewDidLoad 方法中，初始化 numberCount 和标签：

numberCount = 0;
label.text = @"0";

在您的 time 方法中，替换：

numberCount++

为

if(numberCount++ > 19)
    numberCount = 0;

What is the "number" NSString 用于，顺便说一句？

add this to your .h file, in your interface (that is, if it isn't already there)

{
    NSInteger numberCount
}

Then in your viewDidLoad method, initialize numberCount and the label:

numberCount = 0;
label.text = @"0";

And in your time method, replace:

numberCount++

with

if(numberCount++ > 19)
    numberCount = 0;

What is the "number" NSString used for, b.t.w.?

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还如梦归 2024-12-21 03:18:32

为什么要有dayArray？
为什么不像

label.text = [NSString stringWithFormat:@"Day: %d", numberCount++];
if (numberCount>19) numberCount = 0;

我不知道你初始化的数字计数应该是 -1 并且也重新初始化为 -1 。如果您希望迭代“Day: 0”...“Day: 19”
目前还不清楚。

Why have dayArray?
why not something like

label.text = [NSString stringWithFormat:@"Day: %d", numberCount++];
if (numberCount>19) numberCount = 0;

I don't know what you have number count initialized to it should probably be -1 and also reinitialized to -1 . if you wish to iterate thru "Day: 0" ... "Day: 19"
It's not clear.

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淡忘如思 2024-12-21 03:18:32

您可以将 -(void)viewDidLoad 计时器更改为不重复

timer=[NSTimer scheduledTimerWithTimeInterval:5.0 target:self selector:@selector(rotate3 )userInfo:nil repeats:NO];

，如果您仍想在 5 秒后更改文本，则可以在rotate3 方法中有条件地再次设置它。

You could change the -(void)viewDidLoad timer to not repeat

timer=[NSTimer scheduledTimerWithTimeInterval:5.0 target:self selector:@selector(rotate3 )userInfo:nil repeats:NO];

then, conditionally set it up again in the rotate3 method if you still want to change the text 5 seconds later.

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清风夜微凉 2024-12-21 03:18:32

试试这个：

#pragma mark - timer callback

-(IBAction)rotate3
{
    [label1 setText:[dayArray objectAtIndex:numberCount]];
    numberCount++;
    if (numberCount >= [dayArray count])
        numberCount = 0;
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];
    dayArray = [[NSArray alloc] initWithObjects:@"0",@"1",@"2",@"3", nil];
    [label1 setText:[dayArray objectAtIndex:0]];
    numberCount = 1;
    timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(rotate3) userInfo:nil repeats:YES];
    // Do any additional setup after loading the view, typically from a nib.
}

try this:

#pragma mark - timer callback

-(IBAction)rotate3
{
    [label1 setText:[dayArray objectAtIndex:numberCount]];
    numberCount++;
    if (numberCount >= [dayArray count])
        numberCount = 0;
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];
    dayArray = [[NSArray alloc] initWithObjects:@"0",@"1",@"2",@"3", nil];
    [label1 setText:[dayArray objectAtIndex:0]];
    numberCount = 1;
    timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(rotate3) userInfo:nil repeats:YES];
    // Do any additional setup after loading the view, typically from a nib.
}

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