iOS cell上的定時器

  轉載地址：http://blog.csdn.net/littleSun_zheng/article/details/51426859

實現原理： 
1、將資料（資料中的時間部分），以字典（字典中包括：記錄所存資料下標，還有所剩時間 兩個 key）的形式儲存到陣列中。 
2、開啟定時器，執行：遍歷整個陣列，每秒減 一，然後儲存到他原來的位置。 
3、每次減一之後，根據之前記錄的下標找到對應的Cell，然後修改上面的數。這樣就可以了。 
提示：分組型別的tableView 也是沒有一點問題的。效果如APP“E中醫”裡面的名醫出診功能。 
簡單的一個demo: 
command + a 程式碼（直接貼上到剛剛新建工程的ViewController.m檔案中即可）：

<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;"><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//  ViewController.m</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//  CountdownDemo</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//  Created by 鄭鵬 on 16/5/16.</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//  Copyright © 2016年 littleSun_zheng. All rights reserved.</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//</span>

<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#import <span class="hljs-title" style="box-sizing: border-box;">"ViewController.h"</span></span>

<span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@interface</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">ViewController</span> ()<<span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">UITableViewDataSource</span>>{</span>

    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//存放假資料的陣列</span>
    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> *_textArry;

    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//時間倒數計時的 時間陣列</span>
    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> *_totalLastTime;

    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//定時器</span>
    NSTimer *_timer;

    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//記錄 indexPath</span>
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> _num;


}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@property</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">nonatomic</span>,<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">strong</span>)<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UITableView</span> *tableView;


<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@end</span>

<span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@implementation</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">ViewController</span></span>

- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)viewDidLoad {
    [<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span> viewDidLoad];
    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Do any additional setup after loading the view, typically from a nib.</span>

    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//模擬倒數計時   資料</span>

    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//模擬所用資料</span>
    [<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span> _modelData];


    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//初始化 tableView</span>
    [<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span> _creatTableView];


    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//處理資料   並  在主執行緒 開啟定時器</span>
    [<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span> _operateData];


}
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#pragma mark--假資料</span>
- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)_modelData{

    _totalLastTime = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> array];
    _textArry = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> array];

    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> i = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>; i < <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">101</span>; i++) {
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (i%<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span> == <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>) {
            [_textArry addObject:[<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSNumber</span> numberWithInt:i]];
        }
    }

}
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#pragma mark--初始化標檢視</span>
- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)_creatTableView{

    _tableView = [[<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UITableView</span> alloc] initWithFrame:CGRectMake(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">64</span>, [UIScreen mainScreen]<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.bounds</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.size</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.width</span> ,[UIScreen mainScreen]<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.bounds</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.size</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.height</span> - <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">64</span>) style:UITableViewStylePlain];
    _tableView<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.dataSource</span> = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span>;
    _tableView<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.rowHeight</span> = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">44</span>;
    [<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.view</span> addSubview:_tableView];

}
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#pragma mark -- 處理資料   並  在主執行緒 開啟定時器</span>
- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)_operateData{

    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (_textArry<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.count</span> != <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>) {

        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> i=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>; i<_textArry<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.count</span>; i++) {

            <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSNumber</span> *allSecond = _textArry[i];
            <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSInteger</span> remainIntSecond = [allSecond integerValue];
            <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSDictionary</span> *dic = @{@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"indexPath"</span>:[<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> stringWithFormat:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%i"</span>,i],@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"lastTime"</span>: [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> stringWithFormat:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%ld"</span>,(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">long</span>)remainIntSecond]};

            [_totalLastTime addObject:dic];

        }
    }

    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">dispatch_async</span>(dispatch_get_main_queue(), ^{

        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//開啟定時器</span>
        [<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span> _startTimer];
        [_tableView reloadData];


    });
}
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#pragma mark--開啟定時器  時處理</span>
- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)_startTimer{

    _timer = [NSTimer scheduledTimerWithTimeInterval:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.0</span> target:<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">self</span> selector:<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@selector</span>(refreshLessTime) userInfo:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">nil</span> repeats:<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">YES</span>];
    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//如果不新增下面這條語句，在UITableView拖動的時候，會阻塞定時器的呼叫（為什麼我還不怎麼明白，希望能相互交流）</span>
    [[NSRunLoop currentRunLoop] addTimer:_timer forMode:UITrackingRunLoopMode];
}

- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)refreshLessTime{

    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> time;

        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> i = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>; i < _totalLastTime<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.count</span>; i++) {

            time = [[[_totalLastTime objectAtIndex:i] objectForKey:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"lastTime"</span>] intValue];

            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (time > <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>) {

                <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSIndexPath</span> *indexPath = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSIndexPath</span> indexPathForRow:[[[_totalLastTime objectAtIndex:i] objectForKey:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"indexPath"</span>] integerValue] inSection:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>];

                <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UITableViewCell</span> *cell = [_tableView cellForRowAtIndexPath:indexPath];
                cell<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.textLabel</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.text</span> = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> stringWithFormat:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%i"</span>, time];
                time = time - <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>;
                <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSDictionary</span> *dic = @{@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"indexPath"</span>: [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> stringWithFormat:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%d"</span>,i],@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"lastTime"</span>: [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> stringWithFormat:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%i"</span>,time]};
                [_totalLastTime replaceObjectAtIndex:i withObject:dic];

            }<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {

                <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSIndexPath</span> *indexPath = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSIndexPath</span> indexPathForRow:[[[_totalLastTime objectAtIndex:i] objectForKey:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"indexPath"</span>] integerValue] inSection:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>];
                <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UITableViewCell</span> *cell = [_tableView cellForRowAtIndexPath:indexPath];
                cell<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.textLabel</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.text</span> = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> stringWithFormat:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"littleSun倒數計時結束"</span>];

            }

        }

}

<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#pragma mark--UITableViewDataSource</span>
- (<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSInteger</span>)tableView:(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UITableView</span> *)tableView numberOfRowsInSection:(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSInteger</span>)section{

    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> _totalLastTime<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.count</span>;

}
- (<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UITableViewCell</span> *)tableView:(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UITableView</span> *)tableView cellForRowAtIndexPath:(<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSIndexPath</span> *)indexPath{

    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> *countdownCell = @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"CountdownDemo_Cell"</span>;

    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UITableViewCell</span> *cell = [tableView dequeueReusableCellWithIdentifier:countdownCell];

    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (cell == <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">nil</span>) {
        cell= [[<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">UITableViewCell</span> alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:countdownCell];
    }

    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> *remainSecond =  _textArry[indexPath<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.row</span>];
    cell<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.textLabel</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.text</span> = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> stringWithFormat:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"還剩下：%@ 秒"</span>,remainSecond];

    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> cell;
}

- (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span>)didReceiveMemoryWarning {
    [<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span> didReceiveMemoryWarning];
    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Dispose of any resources that can be recreated.</span>
}

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">@end</span></code>