NSTimer定时器的简单用法/NSTimer Instance

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NSTimer定时器的简单用法

版本信息:

OS version : 10.10

Interface Name: NSTimer

Location : Frameworks/Foundation/NSTimer.h


OC源码:


#import <Foundation/NSObject.h>

#import <Foundation/NSDate.h>


@interface NSTimer :NSObject

//类方法

+ (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget selector:(SEL)aSelector userInfo:(id)userInfo repeats:(BOOL)yesOrNo;



今天只关注上面的这个类方法,这个类方法很实用滴,(打印日志文件,纪录用户操作等等)。

以打印日志文件为例,需要用到3个文件:

Log.h

#import <Foundation/Foundation.h>@interface Log : NSObject- (void) Log;//for log- (void) timerAction:(NSTimer *)timer;@end


Log.m

#import "Log.h"@implementation Log- (void)Log{        NSFileManager *fileManager = [NSFileManager defaultManager];    NSString *path = NSHomeDirectory();    NSString *filePath = [path stringByAppendingString:@"/IOS/Log.txt"];//create a txt file for log    BOOL success = [fileManager createFileAtPath:filePath contents:nil attributes:nil];    if (success) {        NSLog(@"create success");    }    //NSFileHandle for handle the txt file    NSFileHandle *fileHandle = [NSFileHandle fileHandleForWritingAtPath:filePath];    [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(timerAction:) userInfo:fileHandle repeats:YES];    //NSTimer定时器使用,每一秒call一次timerAction,写入当前时间到txt file 里面}- (void) timerAction:(NSTimer *)timer{    static int i = 0;        NSFileHandle *fileHandle = timer.userInfo;    [fileHandle seekToEndOfFile];        NSDate *now = [NSDate date];    NSDateFormatter *dateFormate = [[NSDateFormatter alloc] init];    [dateFormate setDateFormat:@" --- yyyy/MM/dd HH:mm:ss"];    NSString *dateNowString = [dateFormate stringFromDate:now];    dateNowString = [dateNowString stringByAppendingString:@"\n"];    NSData *data = [dateNowString dataUsingEncoding:NSUTF8StringEncoding];    [fileHandle writeData:data];        if (i == 10) {        [timer invalidate];        [fileHandle closeFile];    }    i++;}@end


main.m

#import <Foundation/Foundation.h>#import "Log.h"int main(int argc, const char * argv[]) {    @autoreleasepool {        // insert code here...        Log *write = [[Log alloc] init];        [write log];            }    [[NSRunLoop currentRunLoop] run];//NSTImer 和 NSRunLoop 配合使用    return 0;}







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