一、沙盒
模拟器上的沙盒目录路径
~/Library/Application Support/iPhone Simulator/6.0/Applications
获取沙盒的目录路径
//NSHomeDirectory : 获取沙盒的目录路径
NSString *homePath =NSHomeDirectory();
NSLog(@"沙盒目录：%@",homePath);
NSString *docPath1 = [NSStringstringWithFormat:@"%@/Documents",homePath];
NSString *docPath2 = [homePathstringByAppendingFormat:@"/Documents"];
NSLog(@"docPath1=%@,docPath2=%@",docPath1,docPath2);
二、文件管理
2.1 NSString处理路径
//NSString处理路径
NSString *path =@"/Users/apple/file.text";
//1.获取路径的组成部分结果：（"/","Users","apple","file.text")
NSArray *components = [pathpathComponents];
//2.路径的最后一个组成部分结果：file.text
NSString *lastName = [pathlastPathComponent];
//3.追加文件或目录结果：/Users/apple/file.text/app.text
NSString *filePath = [pathstringByAppendingString:@"app.text"];
//4.删除最后的组成部分/扩展名
NSString *deletePath = [pathstringByDeletingLastPathComponent];
NSString *deleteExt = [pathstringByDeletingPathExtension];
//5.获取扩展名/追加扩展名
NSString *ext = [pathpathExtension];
NSString *extPath = [pathstringByAppendingPathExtension:@"jpg"];
2.2 NSData数据处理
NSData是一种对数据的抽象
任何数据都可以通过NSData来存储，NSMutableData是可变的，继承于NSData
2.3 NSFileManager
NSFileManager主要对文件进行管理，主要功能：
NSFileManager管理文件的常用方法
//NSHomeDirectory : 获取沙盒的目录路径
NSString *homePath =NSHomeDirectory();
NSLog(@"沙盒目录：%@",homePath);
//1.创建一个文件并写入数据
NSString* filePath = [homePathstringByAppendingPathComponent:@"Documents/1.jpg"];
//NSFileManager 只能有一个实例对象，不能用alloc创建
NSFileManager* fileManager = [NSFileManagerdefaultManager];
BOOL result = [fileManagercreateFileAtPath:filePathcontents:nilattributes:nil];
if(result)
NSLog(@"file create success");
else
NSLog(@"file create fail");
//2.创建文件夹
filePath = [homePath stringByAppendingPathComponent:@"Documents/model/Smile/pic/01"];
NSLog(@"%@",filePath);
NSError *error;
result = [fileManager createDirectoryAtPath:filePathwithIntermediateDirectories:YESattributes:nilerror:&error];
if(result)
NSLog(@"file dir create success");
else
NSLog(@"file dir create fail");
//3.读取文件中的数据
filePath = [homePath stringByAppendingPathComponent:@"Documents/1.jpg"];
NSData *data = [fileManagercontentsAtPath:filePath];
NSString *string = [[NSStringalloc] initWithData:dataencoding:NSUTF8StringEncoding];
NSLog(@"%@",string);
//4.移动文件
NSString* targetPath = [homePathstringByAppendingPathComponent:@"Documents/model/Smile/pic/01/1.jpg"];
result = [fileManager moveItemAtPath:filePathtoPath:targetPath error:nil];
if(result)
NSLog(@"file move success");
//5.复制文件
result = [fileManager copyItemAtPath:targetPathtoPath:filePath error:nil];
if(result)
NSLog(@"file copy success");
//6.删除文件
BOOL fileExist = [fileManagerfileExistsAtPath:filePath];
if(fileExist)
{
result = [fileManager removeItemAtPath:filePatherror:nil];
if(result)
NSLog(@"file remove success");
}
//7.获取文件大小
NSDictionary* fileAttr = [fileManagerattributesOfItemAtPath:targetPatherror:nil];
NSLog(@"%@",fileAttr);
NSNumber *fileSize = [fileAttrobjectForKey:NSFileSize];
int sizeValue = [fileSizeintValue];
NSLog(@"文件大小%d",sizeValue);
2.4 写文件
数组NSArray、字典NSDictionary、字符串NSString、NSData 都是容纳数据的
NSArray、NSDictionary中只能
存入NSNumber、NSString、NSData、NSDate、NSArray、NSDictionary
才能写入文件，写入后以xml方式存储
它们都有一个writeToFile方法将数据写入文件
//NSString 读写文件
filePath = [homePath stringByAppendingPathComponent:@"Documents/file.text"];
NSString *s =@"Hello iOS";
[s writeToFile:filePathatomically:YESencoding:NSUTF8StringEncodingerror:nil];
NSString *fileString = [NSStringstringWithContentsOfFile:filePathencoding:NSUTF8StringEncodingerror:nil];
NSLog(@"%@",fileString);
//NSData 读写文件
NSData *data = [[NSDataalloc] initWithContentsOfFile:filePath];
fileString = [[NSStringalloc] initWithData:dataencoding:NSUTF8StringEncoding];
NSLog(@"%@",fileString);
[data writeToFile:filePathatomically:YES];
//NSArray 读写文件
filePath = [homePath stringByAppendingPathComponent:@"Documents/array.plist"];
NSString *s1 =@"voron";
NSString *s2 =@"lisa";
NSArray *array = [[NSArrayalloc] initWithObjects:s1,s2,nil];
result = [array writeToFile:filePathatomically:YES];
if(result)
NSLog(@"NSArray write to file success");
NSArray* readArray = [[NSArrayalloc] initWithContentsOfFile:filePath];
for(NSString *sin readArray)
NSLog(@"s=%@",s);
//NSDictionary 读写文件
NSDictionary *dict =@{
@"name":@"jack",
@"birth":[NSDatedate],
@"age":@22
};
filePath = [homePath stringByAppendingPathComponent:@"Documents/dict.plist"];
result = [dict writeToFile:filePathatomically:YES];
NSDictionary *readDict = [NSDictionarydictionaryWithContentsOfFile:filePath];
NSLog(@"%@",readDict);
//NSFileHandle
//1.追加写入数据
//创建一个写入的FileHandle对象
NSFileHandle *writeHandle = [NSFileHandlefileHandleForWritingAtPath:filePath];
[writeHandle seekToEndOfFile];
NSString *appendString =@"appending data";
NSData* data = [appendStringdataUsingEncoding:NSUTF8StringEncoding];
[writeHandle writeData:data];
[writeHandle closeFile];
//2.定位读取
NSFileHandle *readHandle = [NSFileHandlefileHandleForReadingAtPath:filePath];
//获得文件长度
NSDictionary* fileAttr = [fileManagerattributesOfItemAtPath:filePatherror:nil];
NSNumber *fileSize = [fileAttrobjectForKey:NSFileSize];
unsignedlong long sizeValue = [fileSizelongLongValue];
//设置偏移量
[readHandle seekToFileOffset:sizeValue/2];
data = [readHandle readDataToEndOfFile];
NSString *dataString = [[NSStringalloc] initWithData:dataencoding:NSUTF8StringEncoding];
NSLog(@"%@",dataString);
三、文件读写类和文件管理类实现
3.1 File类
File.h
#ifndef File_h
#define File_h
enum FileType
{
FT_WriteOnly,
FT_ReadOnly,
FT_ReadWrite
};
class File
{
public:
File(const char* relPath,NSString* absolutePath);
virtual ~File();
void Open(FileType type);
void Write(const char* data,int size);
void Read(char*& data,int size);
void Close();
private:
NSFileHandle *fileHandle;
const char* relativePath;
NSString* absolutePath;
};
#endif /* File_h */
File.mm
#import <Foundation/Foundation.h>
#import "File.h"
File::File(const char* relPath,NSString* absPath)
:relativePath(relPath),
absolutePath(absPath)
{
//
}
File::~File()
{
//
}
void File::Open(FileType type)
{
if(FT_WriteOnly == type)
{
fileHandle = [NSFileHandle fileHandleForWritingAtPath:absolutePath];
[fileHandle seekToEndOfFile];
}
else if(FT_ReadOnly == type)
{
fileHandle = [NSFileHandle fileHandleForReadingAtPath:absolutePath];
}
else if(FT_ReadWrite == type)
{
fileHandle = [NSFileHandle fileHandleForUpdatingAtPath:absolutePath];
}
}
void File::Write(const char *data, int size)
{
NSData *data_ = [NSData dataWithBytes:data length:size];
[fileHandle writeData:data_];
}
void File::Read(char *&data, int size)
{
//
}
void File::Close()
{
[fileHandle closeFile];
}
3.2 FileManager类
FileManager.h
#ifndef FileManager_h
#define FileManager_h
#include <map>
#include "Singleton.h"
#include "File.h"
using std::map;
class FileManager : public Singleton<FileManager>
{
public:
FileManager();
virtual ~FileManager();
File* CreateFile(const char* relativePath);
private:
NSFileManager *fileManager;
NSString *mainPath;
map<const char*,File*> fileMap;
};
#endif /* FileManager_h */
FileManager.mm
#import <Foundation/Foundation.h>
#import "FileManager.h"
template<>
FileManager* Singleton<FileManager>::ms_pSingleton(0);
FileManager::FileManager()
{
fileManager = [NSFileManager defaultManager];
NSString *homePath = NSHomeDirectory();
mainPath = [homePath stringByAppendingPathComponent:@"Documents"];
}
FileManager::~FileManager()
{
}
File* FileManager::CreateFile(const char *relativePath)
{
NSString* relPath = [NSString stringWithUTF8String:relativePath];
NSString* relativePathWithoutLast = [relPath stringByDeletingLastPathComponent];
NSString* filePath = [mainPath stringByAppendingPathComponent:relativePathWithoutLast];
NSLog(@"%@",filePath);
BOOL fileExist = [fileManager fileExistsAtPath:filePath];
if(!fileExist)
{
BOOL result = [fileManager createDirectoryAtPath:filePath withIntermediateDirectories:YES attributes:nil error:nil];
if(result)
NSLog(@"file dir create success");
else
NSLog(@"file dir create fail");
}
filePath = [mainPath stringByAppendingPathComponent:relPath];
NSLog(@"%@",filePath);
fileExist = [fileManager fileExistsAtPath:filePath];
if(!fileExist)
{
BOOL result = [fileManager createFileAtPath:filePath contents:nil attributes:nil];
if(result)
{
NSLog(@"file create success");
File* file = new File(relativePath,filePath);
fileMap[relativePath] = file;
return file;
}
else
NSLog(@"file create fail");
}
else
{
if(fileMap.find(relativePath) != fileMap.end())
return fileMap[relativePath];
File* file = new File(relativePath,filePath);
fileMap[relativePath] = file;
return file;
}
return 0;
}