iOS read file classes and common methods

First, Nsfilehandle

The Nsfilemanager class mainly operates on files (delete, modify, move, copy, etc.)

The Nsfilehandle class mainly reads and writes the contents of a file

Second, the Nsfilehandle class processes the file the step

Create a Nsfilehandle object

To i/0 an open file

Close File

You can use Nsfilehandle to make a breakpoint continuation

Third, the code to implement the lookup function:

NSString *homepath=nshomedirectory ();

NSString *filepath=[homepath stringbyappendingpathcomponent:@ "Desktop/hello.rtf"];

Nsfilehandle *filehandle=[nsfilehandle Filehandleforreadingatpath:filepath];

Nsuinteger Length=[filehandle availabledata].length;

[FileHandle SEEKTOFILEOFFSET:LENGTH/2];

NSData *data=[filehandle Readdatatoendoffile];

NSString *str=[[nsstring alloc] Initwithdata:data encoding:nsutf8stringencoding];

NSLog (@ "%@", str);

Implementation of append file code:

NSString *homepath=nshomedirectory ();

NSString *filepath=[homepath stringbyappendingpathcomponent:@ "Desktop/hello.rtf"];

Nsfilehandle *filehandle=[nsfilehandle Filehandleforupdatingatpath:filepath];

[FileHandle Seektoendoffile];

[FileHandle Seektofileoffset:10];

NSString *str=@ "Data";

NSData *data=[str datausingencoding:nsutf8stringencoding];

[FileHandle Writedata:data];

[FileHandle CloseFile];

Insert code here ...

NSLog (@ "Hello, world!");

The code to implement the copied file:

NSString *homepath=nshomedirectory ();

NSString *filepath=[homepath stringbyappendingpathcomponent:@ "Desktop/hello.rtf"];

NSString *objpath=[homepath stringbyappendingpathcomponent:@ "Desktop/copy.rtf"];

Nsfilemanager *filemanager=[nsfilemanager Defaultmanager];

BOOL Success=[filemanager Createfileatpath:objpath Contents:nil Attributes:nil];

Nsfilehandle *writefile=[nsfilehandle Filehandleforreadingatpath:filepath];

Nsfilehandle *objfile=[nsfilehandle Filehandleforwritingatpath:objpath];

[objFILE Readdatatoendoffile];

NSData *data=[writefile Readdatatoendoffile];

[objFILE Writedata:data];

[WriteFile CloseFile];

[objFILE CloseFile];