数据的存储－NSKeyedArchiver和write to file介绍

NSString *filePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];filePath = [filePath stringByAppendingPathComponent:@"data.zip"];[NSKeyedArchiver archiveRootObject:[@"dalsfjldkjflas" dataUsingEncoding:NSUTF8StringEncoding] toFile:filePath];NSData *fileData = [[NSData alloc] init];fileData = [NSKeyedUnarchiver unarchiveObjectWithFile:filePath];NSString *fileString = [[NSString alloc] initWithData:fileData encoding:NSUTF8StringEncoding];NSLog(@"fileStirng = %@", fileString);

关键方法：

NSKeyedArchiver类的归档存储方法：archiveRootObject：toFile：

NSKeyedUnarchiver类的解压方法：unarchiveObjectWithFile

使用write to file 方法写入文件：

// 将数据保存到文件NSString *filePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];filePath = [filePath stringByAppendingPathComponent:@"stirng1.zip"];NSLog(@"%@", filePath);NSString *string = @"write to the file method";[string writeToFile:filePath atomically:YES encoding:NSStringEncodingConversionExternalRepresentation error:nil];// 从文件中提取相应的数据NSString *stringFile = [[NSString alloc] initWithContentsOfFile:filePath encoding:NSStringEncodingConversionExternalRepresentation error:nil];NSLog(@"%@", stringFile);在一般的数据类型例如：NSArray，NSMutableArray，NSDictionary，NSMutableDictionary，NSData，NSMutableData，，NSString，NSMutableString，NSNumber，NSDate中，都有一个方法为writetofile。我们可以使用这个方法将数据存放到起来。

关键存放方法：writeToFile

关键提取方法：initwithContentOfFile

德高培身，财多伤身。