将日志写入沙盒mylog.log文件中

//将日志写入沙盒mylog.log文件中
-(void)writeLogMessageToLocationFile:(NSString *)logMessagesString isCover:(BOOL)isCover{

// NSDocumentDirectory 要查找的文件
// NSUserDomainMask 代表从用户文件夹下找
// 在iOS中，只有一个目录跟传入的参数匹配，所以这个集合里面只有一个元素
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsPath = [paths objectAtIndex:0];
NSString *loggingPath = [documentsPath stringByAppendingPathComponent:@"/mylog.log"];
NSLog(@"%@",loggingPath);

//覆盖文件的原先内容
if(isCover == YES) {
[logMessagesString writeToFile:loggingPath atomically:YES encoding:NSUTF8StringEncoding error:nil];

}
else {
NSFileManager *fileManger = [NSFileManager defaultManager];
if (![fileManger fileExistsAtPath:loggingPath]) {
[logMessagesString writeToFile:loggingPath atomically:YES encoding:NSUTF8StringEncoding error:nil];
}
NSFileHandle *fileHandle = [NSFileHandle fileHandleForUpdatingAtPath:loggingPath];
[fileHandle seekToEndOfFile];  //将节点跳到文件的末尾

NSData* stringData  = [logMessagesString dataUsingEncoding:NSUTF8StringEncoding];

[fileHandle writeData:stringData]; //追加写入数据

[fileHandle closeFile];

}

}