iPhone 文件读写操作

1，写文件操作

- (IBAction)btnWrite:(id)sender {
    //创建文件管理器
    NSFileManager *fileManager = [NSFileManager defaultManager];
    //获取路径
    //参数 要获取的哪种路径
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentDirectory = [paths objectAtIndex:0];//去除需要的路径
    //更改到操作的目录下
    [fileManager changeCurrentDirectoryPath:[documentDirectory stringByExpandingTildeInPath]];
     //创建文件fileName文件名称，contents文件内容，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];
    //删除待删除文件
    [fileManager removeItemAtPath:@"createNewFile" error:nil];
    //获取文件路径
    NSString *path = [documentDirectory stringByAppendingPathComponent:@"fileName"];
    NSLog(@"path == %@",path);
    //待写入的数据
    NSString *temp = @"Hello world";
    int data0 = 1000000;
    float data2 = 23.23f;
    //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]];
    [writer appendBytes:&data0 length:sizeof(data0)];
    [writer appendBytes:&data2 length:sizeof(data2)];
     
    [writer writeToFile:path atomically:YES];
    [writer release];    
}

2，读文件操作

- (IBAction)btnRead:(id)sender {
    //创建文件管理器
    NSFileManager *fileManager = [NSFileManager defaultManager];
    //获取路径
    //参数 要获取的哪种路径
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentDirectory = [paths objectAtIndex:0];//去除需要的路径
    //更改到操作的目录下
    [fileManager changeCurrentDirectoryPath:[documentDirectory stringByExpandingTildeInPath]];
     //创建文件fileName文件名称，contents文件内容，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];
    //删除待删除文件
    [fileManager removeItemAtPath:@"createNewFile" error:nil];
    //获取文件路径
    NSString *path = [documentDirectory stringByAppendingPathComponent:@"fileName"];
    NSLog(@"path == %@",path);
    //待写入的数据
    NSString *temp = @"Hello world";
    int data0 = 1000000;
    float data2 = 23.23f;
    //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]];
    [writer appendBytes:&data0 length:sizeof(data0)];
    [writer appendBytes:&data2 length:sizeof(data2)];
     
    [writer writeToFile:path atomically:YES];
    [writer release];
    
    //读取操作
    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;
     
}

iphone实现文件的读写操作

iphone可以很容易的实现文件的读写,但是如果你没有使用苹果公司99美元开发者sdk的话,你利用破解打出来的api包,安装到手机上不能把文件写入手机.下面是我实现读写的代码:

#import "ManagerFile.h"

@implementation ManagerFile

-(void)writeFile:(NSString *)file 
{ 
    //创建文件管理器 
    NSFileManager *fileManager = [NSFileManager defaultManager]; 
    //获取路径 
    //参数NSDocumentDirectory要获取那种路径 
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
    NSString *documentsDirectory = [paths objectAtIndex:0];//去处需要的路径   
    //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 
    //获取文件路径 
    [fileManager removeItemAtPath:@"username" error:nil]; 
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"username"]; 
    //创建数据缓冲 
    NSMutableData *writer = [[NSMutableData alloc] init]; 
    //将字符串添加到缓冲中 
    [writer appendData:[file dataUsingEncoding:NSUTF8StringEncoding]]; 
    //将其他数据添加到缓冲中 
    //将缓冲的数据写入到文件中 
    [writer writeToFile:path atomically:YES]; 
    [writer release]; 
} 
-(NSString *)readFile 
{ 
    //创建文件管理器 
    NSFileManager *fileManager = [NSFileManager defaultManager]; 
    //获取路径 
    //参数NSDocumentDirectory要获取那种路径 
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
    NSString *documentsDirectory = [paths objectAtIndex:0];//去处需要的路径   
    //更改到待操作的目录下 
    [fileManager changeCurrentDirectoryPath:[documentsDirectory stringByExpandingTildeInPath]]; 
    //获取文件路径 
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"username"]; 
    NSData *reader = [NSData dataWithContentsOfFile:path]; 
    return [[NSString alloc] initWithData:reader 
                                 encoding:NSUTF8StringEncoding]; 
} 
@end

 

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