- (IBAction)btnWrite:(id)sender {  //創建文件管理器  NSFileManager *fileManager = [NSFileManager defaultManager];  //獲取路徑  //參數 要獲取的哪種路徑  NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);  NSString *documentDirectory = [paths objectAtIndex:0];//去除需要的路徑  //更改到操作的目錄下  [fileManager changeCurrentDirectoryPath:[documentDirectory stringByExpandingTildeInPath]];   //創建文件fileName文件名稱，contents文件內容，如果開始沒有內容可以設置為nil，attributes文件的屬性,初始為nil  [fileManager createFileAtPath:@"fileName" contents:nil attributes:nil];  //刪除待刪除文件  [fileManager removeItemAtPath:@"createNewFile" error:nil];  //獲取文件路徑  NSString *path = [documentDirectory stringByAppendingPathComponent:@"fileName"];  NSLog(@"path == %@",path);  //待寫入的數據  NSString *temp = @"Hello world";  int data0 = 1000000;  float data2 = 23.23f;  //創建數據緩沖  NSMutableData *writer = [[NSMutableData alloc]init];  //將字符串添加到緩沖中  [writer appendData:[temp dataUsingEncoding:NSUTF8StringEncoding]];  [writer appendBytes:&data0 length:sizeof(data0)];  [writer appendBytes:&data2 length:sizeof(data2)];     [writer writeToFile:path atomically:YES];  [writer release];  }

- (IBAction)btnRead:(id)sender {  //創建文件管理器  NSFileManager *fileManager = [NSFileManager defaultManager];  //獲取路徑  //參數 要獲取的哪種路徑  NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);  NSString *documentDirectory = [paths objectAtIndex:0];//去除需要的路徑  //更改到操作的目錄下  [fileManager changeCurrentDirectoryPath:[documentDirectory stringByExpandingTildeInPath]];   //創建文件fileName文件名稱，contents文件內容，如果開始沒有內容可以設置為nil，attributes文件的屬性,初始為nil  [fileManager createFileAtPath:@"fileName" contents:nil attributes:nil];  //刪除待刪除文件  [fileManager removeItemAtPath:@"createNewFile" error:nil];  //獲取文件路徑  NSString *path = [documentDirectory stringByAppendingPathComponent:@"fileName"];  NSLog(@"path == %@",path);  //待寫入的數據  NSString *temp = @"Hello world";  int data0 = 1000000;  float data2 = 23.23f;  //創建數據緩沖  NSMutableData *writer = [[NSMutableData alloc]init];  //將字符串添加到緩沖中  [writer appendData:[temp dataUsingEncoding:NSUTF8StringEncoding]];  [writer appendBytes:&data0 length:sizeof(data0)];  [writer appendBytes:&data2 length:sizeof(data2)];     [writer writeToFile:path atomically:YES];  [writer release];    //讀取操作  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 == %d",gData0);  NSLog(@"gData1 == %f",gData1);  NSLog(@"gData2 == %@",gData2);    // lblText.text = gData2;   }

#import "ManagerFile.h"@implementation ManagerFile-(void)writeFile:(NSString *)file {   //創建文件管理器   NSFileManager *fileManager = [NSFileManager defaultManager];   //獲取路徑   //參數NSDocumentDirectory要獲取那種路徑   NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);   NSString *documentsDirectory = [paths objectAtIndex:0];//去處需要的路徑    //更改到待操作的目錄下   [fileManager changeCurrentDirectoryPath:[documentsDirectory stringByExpandingTildeInPath]];   //創建文件fileName文件名稱，contents文件的內容，如果開始沒有內容可以設置為nil，attributes文件的屬性，初始為nil   //獲取文件路徑   [fileManager removeItemAtPath:@"username" error:nil];   NSString *path = [documentsDirectory stringByAppendingPathComponent:@"username"];   //創建數據緩沖   NSMutableData *writer = [[NSMutableData alloc] init];   //將字符串添加到緩沖中   [writer appendData:[file dataUsingEncoding:NSUTF8StringEncoding]];   //將其他數據添加到緩沖中   //將緩沖的數據寫入到文件中   [writer writeToFile:path atomically:YES];   [writer release]; } -(NSString *)readFile {   //創建文件管理器   NSFileManager *fileManager = [NSFileManager defaultManager];   //獲取路徑   //參數NSDocumentDirectory要獲取那種路徑   NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);   NSString *documentsDirectory = [paths objectAtIndex:0];//去處需要的路徑    //更改到待操作的目錄下   [fileManager changeCurrentDirectoryPath:[documentsDirectory stringByExpandingTildeInPath]];   //獲取文件路徑   NSString *path = [documentsDirectory stringByAppendingPathComponent:@"username"];   NSData *reader = [NSData dataWithContentsOfFile:path];   return [[NSString alloc] initWithData:reader                  encoding:NSUTF8StringEncoding]; } @end