iPhone 文件读写操作

1，写文件操作

 1 - (IBAction)btnWrite:(id)sender {
 2     //创建文件管理器
 3     NSFileManager *fileManager = [NSFileManager defaultManager];
 4     //获取路径
 5     //参数 要获取的哪种路径
 6     NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
 7     NSString *documentDirectory = [paths objectAtIndex:0];//去除需要的路径
 8     //更改到操作的目录下
 9     [fileManager changeCurrentDirectoryPath:[documentDirectory stringByExpandingTildeInPath]];
10      //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
11     [fileManager createFileAtPath:@"fileName" contents:nil attributes:nil];
12     //删除待删除文件
13     [fileManager removeItemAtPath:@"createNewFile" error:nil];
14     //获取文件路径
15     NSString *path = [documentDirectory stringByAppendingPathComponent:@"fileName"];
16     NSLog(@"path == %@",path);
17     //待写入的数据
18     NSString *temp = @"Hello world";
19     int data0 = 1000000;
20     float data2 = 23.23f;
21     //创建数据缓冲
22     NSMutableData *writer = [[NSMutableData alloc]init];
23     //将字符串添加到缓冲中
24     [writer appendData:[temp dataUsingEncoding:NSUTF8StringEncoding]];
25     [writer appendBytes:&data0 length:sizeof(data0)];
26     [writer appendBytes:&data2 length:sizeof(data2)];
27      
28     [writer writeToFile:path atomically:YES];
29     [writer release];    
30 }

2，读文件操作

 1 - (IBAction)btnRead:(id)sender {
 2     //创建文件管理器
 3     NSFileManager *fileManager = [NSFileManager defaultManager];
 4     //获取路径
 5     //参数 要获取的哪种路径
 6     NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
 7     NSString *documentDirectory = [paths objectAtIndex:0];//去除需要的路径
 8     //更改到操作的目录下
 9     [fileManager changeCurrentDirectoryPath:[documentDirectory stringByExpandingTildeInPath]];
10      //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
11     [fileManager createFileAtPath:@"fileName" contents:nil attributes:nil];
12     //删除待删除文件
13     [fileManager removeItemAtPath:@"createNewFile" error:nil];
14     //获取文件路径
15     NSString *path = [documentDirectory stringByAppendingPathComponent:@"fileName"];
16     NSLog(@"path == %@",path);
17     //待写入的数据
18     NSString *temp = @"Hello world";
19     int data0 = 1000000;
20     float data2 = 23.23f;
21     //创建数据缓冲
22     NSMutableData *writer = [[NSMutableData alloc]init];
23     //将字符串添加到缓冲中
24     [writer appendData:[temp dataUsingEncoding:NSUTF8StringEncoding]];
25     [writer appendBytes:&data0 length:sizeof(data0)];
26     [writer appendBytes:&data2 length:sizeof(data2)];
27      
28     [writer writeToFile:path atomically:YES];
29     [writer release];
30     
31     //读取操作
32     int gData0;
33     float gData1;
34     NSString *gData2;
35     
36     NSData *reader = [NSData dataWithContentsOfFile:path];
37     gData2 = [[NSString alloc]initWithData:[reader subdataWithRange:NSMakeRange(0, [temp length])] encoding:NSUTF8StringEncoding];
38     [reader getBytes:&gData0 range:NSMakeRange([temp length], sizeof(gData0))];
39     [reader getBytes:&gData1 range:NSMakeRange([temp length]+ sizeof(gData0) , sizeof(gData1))];
40     NSLog(@"gData0 == %d",gData0);
41     NSLog(@"gData1 == %f",gData1);
42     NSLog(@"gData2 == %@",gData2);
43     
44    // lblText.text = gData2;
45      
46 }

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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