iOS中控制NSLog输出时机详解

-(void)saveDEBUGlog{
  NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
  NSString *documentDirectory = [paths objectAtIndex:0];
  
  NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
  [dateFormatter setDateFormat:@"yyyy_MM_dd_HH_mm_ss"];
  NSString *currentDateStr = [dateFormatter stringFromDate:[NSDate date]];
  NSString *fileName = [NSString stringWithFormat:@"testLog_%@.log",currentDateStr];
  
  NSString *logFilePath = [documentDirectory stringByAppendingPathComponent:fileName];
  // 先删除已经存在的文件
  NSFileManager *defaultManager = [NSFileManager defaultManager];
  [defaultManager removeItemAtPath:logFilePath error:nil];
  
  // 将log输入到文件
  freopen([logFilePath cStringUsingEncoding:NSASCIIStringEncoding], "a+", stdout);
  freopen([logFilePath cStringUsingEncoding:NSASCIIStringEncoding], "a+", stderr);
}

#import <Foundation/Foundation.h>

extern BOOL reportLoggerIsOpen;
.m 文件
BOOL reportLoggerIsOpen = NO;

+ (void)setLogOpen:(BOOL)open {
  reportLoggerIsOpen = open;
}