NSFileManager数据文件增删改

#import "TestViewController.h"

@implementation TestViewController


- (void)viewDidLoad {
    [super viewDidLoad];
	
	
	//创建与删除：
    //创建文件管理器
    NSFileManager *fileManager = [NSFileManager defaultManager];
    //获取路径
    //参数NSDocumentDirectory要获取哪种路径 —— 获取    /Documents路径
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];//去处需要的路径
	NSLog(@"%@",documentsDirectory);
	
	//更改到待操作的目录下
    [fileManager changeCurrentDirectoryPath:[documentsDirectory stringByExpandingTildeInPath]];
	
	//创建文件fileName文件名称，contents文件的内容，如果开始没有内容可以设置为nil，attributes文件的属性，初始为nil
    [fileManager createFileAtPath:@"fileName" contents:nil attributes:nil];
	//删除待删除的文件
    [fileManager removeItemAtPath:@"createdNewFile" error:nil];
	
	
	
	//写入数据：
	//获取文件路径
	NSString *path = [documentsDirectory stringByAppendingPathComponent:@"fileName"];
    
    //待写入的数据
    NSString *temp = @"Hello friend";
    int data0 = 100000;
    float data1 = 23.45f;
    
    //创建数据缓冲
    NSMutableData *writer = [[NSMutableData alloc] init];
    
    //将字符串添加到缓冲中
    [writer appendData:[temp dataUsingEncoding:NSUTF8StringEncoding]];
	
    //将其他数据添加到缓冲中
    [writer appendBytes:&data0 length:sizeof(data0)];
    [writer appendBytes:&data1 length:sizeof(data1)];
    
    //将缓冲的数据写入到文件中
    [writer writeToFile:path atomically:YES];
    [writer release];
	

	
	//读取数据：
    int gData0;
    float gData1;
    NSString *gData2;
    
    NSData *reader = [NSData dataWithContentsOfFile:path];
    gData2 = [[NSString alloc] initWithData:[reader subdataWithRange:NSMakeRange(0, [temp length])]
								   encoding:NSUTF8StringEncoding];
    [reader getBytes:&gData0 range:NSMakeRange([temp length], sizeof(gData0))];
    [reader getBytes:&gData1 range:NSMakeRange([temp length] + sizeof(gData0), sizeof(gData1))];
    
    NSLog(@"gData0:%i  gData1:%0.2f gData2:%@", gData0, gData1, gData2);
	

	
/*	
	//读取工程中的文件：
	//读取数据时，要看待读取的文件原有的文件格式，是字节码还是文本，我经常需要重文件中读取字节码，所以我写的是读取字节文件的方式。
    //用于存放数据的变量，因为是字节，所以是ＵInt8
    UInt8 b = 0;
	
    //获取文件路径
    NSString *path8 = [[NSBundle mainBundle] pathForResource:@"fileName" ofType:@""];
	
	//获取数据 
	NSData *reader8 = [NSData dataWithContentsOfFile:path8];
    
	//获取字节的个数
    int length = [reader8 length];
    NSLog(@"------->bytesLength:%d", length);
    for(int i = 0; i < length; i++)
    {
        //读取数据
        [reader8 getBytes:&b range:NSMakeRange(i, sizeof(b))];
        NSLog(@"-------->data%d:%d", i, b);    
        
    }
	
*/	
	
	
	
	
	
/*
	
	
	//创建一个NSFileManager，创建自定义文件夹myTest
	NSFileManager *fileManger = [NSFileManager defaultManager];
	NSString *myDirectory = [documentsDirectory stringByAppendingPathComponent:@"myTest"];
	BOOL ok = [fileManger createDirectoryAtPath:myDirectory attributes:nil];
	
	//取得一个目录下得所有文件名：（如上面的myDirectory)可用
	NSArray *file = [fileManger subpathsOfDirectoryAtPath: myDirectory error:nil]; 
	//或
	//NSArray *files = [fileManager subpathsAtPath: myDirectory ]; 
	
	//读取某个文件:
	NSData *data = [fileManger contentsAtPath:myFilePath];//myFilePath是包含完整路径的文件名
	//或直接用NSData 的类方法：
	//NSData *data = [NSData dataWithContentOfPath:myFilePath]; 
	
	
	//保存某个文件:
	//可以用 NSFileManager的
	- (BOOL)createFileAtPath:(NSString *)path contents:(NSData *)data attributes:(NSDictionary *)attr;
	//或 NSData 的
	- (BOOL)writeToFile:(NSString *)path atomically:(BOOL)useAuxiliaryFile;
	- (BOOL)writeToFile:(NSString *)path options:(NSUInteger)writeOptionsMask error:(NSError **)errorPtr;
*/	
	

	
	
//	NSString *filePath = [[NSBundle mainBundle] bundlePath];//获得app的路径
//2011-08-24 09:52:30.168 Test[619:207] /Users/ibokanwisdom06/Library/Application Support/iPhone Simulator/4.2/Applications/E91BDD30-2DB9-4982-BBCA-EE51A65091BA/Test.app
//	NSString *filePath = [[NSBundle mainBundle] executablePath];//获得test的路径
//2011-08-24 09:52:54.882 Test[649:207] /Users/ibokanwisdom06/Library/Application Support/iPhone Simulator/4.2/Applications/E91BDD30-2DB9-4982-BBCA-EE51A65091BA/Test.app/Test
//	NSString *filePath = [[NSBundle mainBundle] privateFrameworksPath];//获得Frameworks的路径
//	NSLog(@"%@",filePath);

	
	
}



- (void)dealloc {
    [super dealloc];
}

@end