oc文件基本读写及操作

代码：

#import <Foundation/Foundation.h>



//NSString 写文件

void stringWriteToFile(){

    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"/Documents/test.txt"];

    NSString *s = @"test";

    [s writeToFile:path atomically:YES encoding:NSUTF8StringEncoding error:nil];

    

    

    NSString *str = [[NSString alloc] initWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];

    NSLog(@"\nstring = %@",str);

    

    NSString *testtxt = [[NSString alloc] initWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];

    NSLog(@"\ntest.text = %@",testtxt);

}



//NSArray 写文件

void arrayWriteToFile(){

    NSArray *arr = @[@"a",@"b",@"b",@"c"];

    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"/Documents/test2.txt"];

    [arr writeToFile:path atomically:YES];

    

    

    NSArray *a = [[NSArray alloc] initWithContentsOfFile:path];

    NSLog(@"array = \n%@",a);

    

    NSString *s = [[NSString alloc] initWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];

    NSLog(@"\ntest2.txt = \n%@",s);

}



//NSDictionary 写文件

void dictionaryWriteToFile(){

    NSDictionary *dic = @{@"a":@"1",

                          @"b":@"2",

                          @"c":@"3",

                          @"d":@"4"};

    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"/Documents/test3.txt"];

    [dic writeToFile:path atomically:YES];

    

    NSDictionary *d = [[NSDictionary alloc] initWithContentsOfFile:path];

    NSLog(@"\ndictionary = \n%@",d);

    

    NSString *s = [[NSString alloc] initWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];

    NSLog(@"\ntest3.txt = \n%@",s);

}



//atomically 是否原子级  即事务性写入

//NSNumber、NSDate、NSData都可以通过writeToFile写入文件，该文件为纯文本类型，如果将后缀名改为plist即为xcode属性列表文件



int main(int argc, const char * argv[]) {

    

    //该方法是创建一个实例，但是使的NSFileManager的单例模式将失去效果

    NSFileManager *fm0 = [[NSFileManager alloc] init];

    

    //defaultManager使用单例模式创建NSFileManager对象

    NSFileManager *fm1 = [NSFileManager defaultManager];

    

    NSFileManager *fm2 = [NSFileManager defaultManager];

    

    NSLog(@"\nfm0 = %p,fm1 = %p,fm2 = %p",fm0,fm1,fm2);

    

    NSData *data = [[NSString stringWithFormat:@"main"] dataUsingEncoding:NSUTF8StringEncoding];

    

    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/main.txt"];

    

    

    if (![fm1 fileExistsAtPath:path]) {

        if ([fm1 createFileAtPath:path contents: data attributes:nil]) {

            NSLog(@"create success");

            NSDictionary *d = [fm1 attributesOfItemAtPath:path error:nil];

            

            NSLog(@"\nattributesOfItemAtPath = \n%@",d);

            

            //NSFileSize是预定义的文件属性key，可通过查看系统文件获取其他属性key并通过

            //以下方法获取其属性值

            NSNumber *filesize = [d valueForKey:NSFileSize];

            

            NSLog(@"\nfilesize = %@",filesize);

            

            //读文件

            NSData *data1 = [fm1 contentsAtPath:path];

            

            NSString *s = [[NSString alloc] initWithData:data1 encoding:NSUTF8StringEncoding];

            

            //文件系统的属性

            //总空间，已用空间，可用空间，文件数量，

            NSLog(@"\nattributesOfFileSystemForPath = \n%@",[fm1 attributesOfFileSystemForPath:path error:nil]);

            

            NSLog(@"\nmain.txt = %@",s);

        }

    }

    else{

        

        

        NSString *copypath = [NSHomeDirectory() stringByAppendingPathComponent:@"/Documents/main_copy.txt"];

        [fm1 copyItemAtPath:path toPath:copypath error:nil];

        

        

        //重命名可以目标路径与主路径一致但是文件名不同

        NSString *movepath = [NSHomeDirectory() stringByAppendingPathComponent:@"/Documents/main_move.txt"];

        [fm1 moveItemAtPath:path toPath:movepath error:nil];

        

        //删除文件

        if ([fm1 removeItemAtPath:path error:nil]) {

            NSLog(@"remove %@ success",path);

        }

        if ([fm1 removeItemAtPath:copypath error:nil]) {

            NSLog(@"remove %@ success",copypath);

        }

        if ([fm1 removeItemAtPath:movepath error:nil]) {

            NSLog(@"remove %@ success",movepath);

        }

    }

    

    stringWriteToFile();

    

    arrayWriteToFile();

    

    dictionaryWriteToFile();

    

    return 0;

}

结果：

2015-03-08 21:18:26.064 NSFileManagerDemo[1686:79942] 

fm0 = 0x1001145d0,fm1 = 0x100114620,fm2 = 0x100114620

2015-03-08 21:18:26.075 NSFileManagerDemo[1686:79942] remove /Users/yoran_yang/Documents/main_copy.txt success

2015-03-08 21:18:26.076 NSFileManagerDemo[1686:79942] remove /Users/yoran_yang/Documents/main_move.txt success

2015-03-08 21:18:26.076 NSFileManagerDemo[1686:79942] 

string = test

2015-03-08 21:18:26.077 NSFileManagerDemo[1686:79942] 

test.text = test

2015-03-08 21:18:26.078 NSFileManagerDemo[1686:79942] array = 

(

    a,

    b,

    b,

    c

)

2015-03-08 21:18:26.078 NSFileManagerDemo[1686:79942] 

test2.txt = 

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<array>

    <string>a</string>

    <string>b</string>

    <string>b</string>

    <string>c</string>

</array>

</plist>

2015-03-08 21:18:26.079 NSFileManagerDemo[1686:79942] 

dictionary = 

{

    a = 1;

    b = 2;

    c = 3;

    d = 4;

}

2015-03-08 21:18:26.079 NSFileManagerDemo[1686:79942] 

test3.txt = 

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

    <key>a</key>

    <string>1</string>

    <key>b</key>

    <string>2</string>

    <key>c</key>

    <string>3</string>

    <key>d</key>

    <string>4</string>

</dict>

</plist>

Program ended with exit code: 0