iphone 文件操作

1：createDirectoryAtPath  创建目录 
 
- (bool)createPath:(NSString *)fileName 
{ 
NSArray  *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString *documentDirectory = [paths objectAtIndex:0]; 
if (!documentDirectory)  
{                 
return false;                 
} 
 
NSString *FilePath = [[documentDirectory stringByAppendingString:@"/"] stringByAppendingString:fileName]; 
if ([[NSFileManager defaultManager]fileExistsAtPath:FilePath])  
{ 
return true; 
} 
 
[[NSFileManager defaultManager] createDirectoryAtPath:FilePath attributes:nil]; 
if ([[NSFileManager defaultManager]fileExistsAtPath:FilePath])  
{ 
return true; 
} 
 
return false; 
} 
 
 
 
 
2：读取指定文件夹下的所有文件名称 fileExistsAtPath 
- (bool)readSignature:(NSString *)filePath 
{ 
NSArray  *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString *documentDirectory = [paths objectAtIndex:0]; 
if (!documentDirectory)  
{                 
return false;                 
} 
 
NSString *FilePath = [[documentDirectory stringByAppendingString:@"/"] stringByAppendingString:filePath]; 
if (![[NSFileManager defaultManager]fileExistsAtPath:FilePath])  
{ 
return false; 
} 
 
NSArray *files = [[NSFileManager defaultManager] directoryContentsAtPath:FilePath]; 
if (signArray) 
{ 
[signArray release]; 
signArray = nil; 
} 
signArray = [[NSMutableArray alloc] init]; 
[signArray addObjectsFromArray:files]; 
 
return true; 
} 
 
 
3：读取和保存二进制文件 
- (bool) writeApplicationData:(NSData *)data writeFileName:(NSString *)fileName 
{  
if (!fileName) 
{ 
return false; 
} 
 
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);         
NSString *documentDirectory = [paths objectAtIndex:0];  
NSString *FilePath = [documentDirectory stringByAppendingString:@"/signature/"]; 
if (!FilePath)  
{                 
return false;                 
} 
 
NSString *appFile = [FilePath stringByAppendingPathComponent:fileName]; 
return ([data writeToFile:appFile atomically:YES]);  
} 
 
 
-(id) readApplicationData:(NSString *)fileName 
{         
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);         
NSString *documentDirectory = [paths objectAtIndex:0];         
NSString *FilePath = [[documentDirectory stringByAppendingString:@"/signature/"] stringByAppendingString:f
4000
ileName]; 
NSData *myData = [[[NSData alloc] initWithContentsOfFile:FilePath] autorelease];     
return myData;         
}