OC语言系统文件

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系统文件

// ViewController.m

// Tank-OS12-01

// Created by ibokan on 15/12/25.

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

[superviewDidLoad];

NSString *string = [NSStringstringWithContentsOfURL:[NSURLURLWithString:@"http://www.baidu.com"]encoding:NSUTF8StringEncodingerror:nil];

// NSLog(@"string = %@",string);

ios文件系统

当第一次启动app时,ios操作系统就为此app创建了一个文件系统,该文件系统下默认有四个目录,分别是:

Documents:存储用户在操作app时产生的数据,此目录下的数据可以通过iCloud进行同步.

Library:用户偏好设置数据,通常和此类NSUserDefaults搭配使用,此目录下的数据可以通过iCloud进行同步.

tmp:存放临时数据的(缓存).此目录下的数据不会通过iCloud同步.

app包:开发者不会操作此目录,通常是通过此类NSBundle类来获取包内资源,如工程素材.

//获取程序根目录

NSString *rootPath = NSHomeDirectory();

//拼接

NSString *documentsPath = [rootPath stringByAppendingFormat:@"/Documents"];

//或者

documentsPath = [rootPath stringByAppendingPathComponent:@"Documents"];

NSLog(@"%@",documentsPath);

// NSLog(@"rootPath = %@",rootPath); //NSLog增强版,可以log出多一行

// //条件断点

// for (int i = 0; i <100; i++)

// {

// //断点打在这

// }

//常用的获取Documents目录的方法

<#NSSearchPathDirectory directory#>:指定了搜索的路径名称

<#NSSearchPathDomainMask domainMask#>:限定了文件的检索范围只在沙盒(sandbox)内部

<#BOOL expandTilde#>:决定了是否展开波浪线符号,展开后才是完整的路径,这个布尔值一直为YES时才会展开完整的路径.

该方法返回的为一个数组,在iphone中由于只有一个唯一路径,所以直接取数组第一个元素即可.

documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES)objectAtIndex:0];

NSLog(@"%@",documentsPath);

//下载一个视频文件到Documents目录下的Video文件夹

//这里我们封装一个函数,使得这个函数返回的是我们在Documents目录下想要的文件夹的路径.

NSString *videoPath = [self creatDirInDocuments:@"Video"];

NSLog(@"videoPath = %@",videoPath);

if (videoPath != nil) {

NSFileManager *fileManager = [NSFileManager defaultManager];

NSString *videoUrlString = @"http://v8.tv.cctv5.cctv.com/r5wbth/4d/e7/4de76971-63f4-4717-f28b-03d757a7704f/mp4h.mp4";

//取最后一个/后面的字符串,然后再与videoPath拼接,会自动添加'/';

NSString *fileVideo = [videoPath stringByAppendingPathComponent:[videoUrlString lastPathComponent]]; //最后面的[里面是取最后一个'/'后的后缀]

//如果文件夹不存在该路径

if (![fileManager fileExistsAtPath:fileVideo]) {

//转码

// videoUrlString = [videoUrlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

NSCharacterSet *characterSet = [NSCharacterSet URLQueryAllowedCharacterSet];

[videoUrlString stringByAddingPercentEncodingWithAllowedCharacters:characterSet];

//我们的图片/视频/音频等在网络中都是以二进制文件传输,所以这里我们拿到的是data

NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:videoUrlString]];

if (data == nil) {

NSLog(@"网络不给力,稍后再试");

}

else

{

//用单例类NSFileManager的对象,将文件写入本地

BOOL isSuccess = [fileManager createFileAtPath:fileVideo contents:data attributes:nil];

if (isSuccess) {

NSLog(@"视频下载成功");

}

else

{

NSLog(@"视频下载失败");

}

//字符串拼接,获取Library目录

NSString *libraryPath = [rootPath stringByAppendingString:@"/Library"];

NSLog(@"libraryPath = %@",libraryPath);

//第二种

libraryPath = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,NSUserDomainMask, YES)objectAtIndex:0];

NSLog(@"libraryPath = %@",libraryPath);

//tmp

NSString *tmpString = NSTemporaryDirectory();

NSLog(@"tmpString = %@",tmpString);

NSArray *imgsArray =@[@"http://img0.imgtn.bdimg.com/it/u=4149130001,3742834577&fm=11&gp=0.jpg",@"http://img4.imgtn.bdimg.com/it/u=3559701691,1695542011&fm=11&gp=0.jpg",@"http://img1.imgtn.bdimg.com/it/u=3021209900,2363537985&fm=11&gp=0.jpg",@"http://b88.photo.store.qq.com/psb?/V10NeaS93Z1jjj/ea6jOdEb3b.pN.JFn*cdKnHrDXWjCJdETiNdNpxw1VY!/b/dFgAAAAAAAAA&bo=AALSAwAAAAAFAPA!&rf=viewer_4"];

//下载一些图片放到tmp目录下的Imgs文件夹下,如果有些图片已经下载了,那么不会继续下载

NSString *imgsTmpPath = [selfcreateDirInTmp:@"Imgs"];

if (imgsTmpPath != nil) {

// NSLog(@"imgsTmpPath = %@",imgsTmpPath);

for (int i =0; i <imgsArray.count; i++) {

NSString *imgsString = [imgsArray[i]lastPathComponent];

//获得每张图片的路径

NSString *imgsPath = [imgsTmpPath stringByAppendingPathComponent:imgsString];

NSFileManager *fileManager = [NSFileManagerdefaultManager];

if (![fileManager fileExistsAtPath:imgsPath]) { //一定要加个'!'非

NSString *urlString = [imgsArray[i]stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSetURLQueryAllowedCharacterSet]];

//将urlString转化成data

NSData *data2 = [NSDatadataWithContentsOfURL:[NSURLURLWithString:urlString]];

if (data2 == nil) {

NSLog(@"网络有问题,请稍后再试");

}

else

{

BOOL isSuccess = [data2 writeToFile:imgsPath atomically:YES];

if (isSuccess) {

NSLog(@"图片下载成功");

}

else

{

NSLog(@"图片下载失败");

}

//将字符串写入到本地

NSString *targetString = @"Hello guys";

BOOL flag = [targetStringwriteToFile:[imgsTmpPath stringByAppendingPathComponent:@"a.txt"]atomically:YESencoding:NSUTF8StringEncodingerror:nil];

if (flag) {

NSLog(@"字符串写入本地成功");

}

else

{

NSLog(@"字符串写入本地失败");

}

//将数组写入本地文件

NSArray *array =@[@"刘林强",@"黄智威",@"何鹏",@"许毓"];

flag = [array writeToFile:[imgsTmpPathstringByAppendingPathComponent:@"array.txt"]atomically:YES];

if (flag) {

NSLog(@"数组写入成功");

}

else

{

NSLog(@"数组写入失败");

}

//将字典写入本地

NSDictionary *dictionary =@{@"name":@"Rick",@"age":@25,@"address":@"GZ"};

flag = [dictionary writeToFile:[imgsTmpPathstringByAppendingPathComponent:@"dictionary.txt"]atomically:YES];

if (flag) {

NSLog(@"字典写入本地成功");

}

else

{

NSLog(@"字典写入本地失败");

}

//计算文件大小

//获得将要计算的文件夹

NSFileManager *fileManager = [NSFileManagerdefaultManager];// 获得单例类(可以写到头顶,只写一次就好)

//获得imgs目录下文件名组成的数组

NSArray *imgsFileArray = [fileManager subpathsAtPath:imgsTmpPath];

NSLog(@"imgsFileArray = %@",imgsFileArray);

//提取每个文件大小并累加

CGFloat count = 0; //累加用的

for (NSString *elein imgsFileArray) {

NSData *data = [NSDatadataWithContentsOfFile:[imgsTmpPath stringByAppendingPathComponent:ele]]; //后面的是取得 /路径,前面是转化为data

count += data.length; //取出的长度是字节Byte

}

count = count/1024/1024; //由Byte转化为 MB

NSLog(@"缓存文件的大小为: %.2fM",count);

//删除文件

for (NSString *elein imgsFileArray) {

BOOL isSuccess = [fileManager removeItemAtPath: [imgsTmpPath stringByAppendingPathComponent:ele]error:nil];

if (isSuccess) {

NSLog(@"删除成功");

}

else

{

NSLog(@"删除失败");

}

//app包,获取包内图片,显示在UI

NSBundle *bundle = [NSBundlemainBundle];

NSLog(@"bundle = %@",bundle); //获取app包路径

NSString *imgPath = [bundle pathForResource:@"girl" ofType:@".png"]; //.jpg 或者 png(不用点)(其实.png也可以的)

NSData *data = [NSDatadataWithContentsOfFile:imgPath];

NSLog(@"data = %@",data);

self.imagefile.image = [UIImageimageWithData:data];

}

-(NSString *)creatDirInDocuments:(NSString *)dirName

{

//获得Documents文件路径

NSString *documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES)objectAtIndex:0];

//拼接成我们想要的文件的路径的字符串...此方法自动加'/';

NSString *dirDocuments = [documentsPath stringByAppendingPathComponent:dirName];

//创建文件夹

//获取NSFileManager单例类,用于文件操作,在哪里声明都一样的

NSFileManager *fileManager = [NSFileManagerdefaultManager];

//判断本地是否存在某个文件或文件夹

BOOL isExist = [fileManager fileExistsAtPath:dirDocuments];

if ( !isExist ) {

//创建文件夹

NSError *error;

BOOL isSuccess = [fileManagercreateDirectoryAtPath:dirDocuments withIntermediateDirectories:YESattributes:nilerror:&error];

if (!isSuccess) {

//如果文件创建失败,将打印错误的信息

NSLog(@"error = %@",error.debugDescription); //查看为什么错

dirDocuments = nil;

}

return dirDocuments;

}

-(NSString *)createDirInTmp:(NSString *)dirName

{

NSString *tmp =NSTemporaryDirectory();

//想要文件的路径

NSString *dirPath = [tmp stringByAppendingPathComponent:dirName];

NSFileManager *fileManager = [NSFileManagerdefaultManager];

if (![fileManager fileExistsAtPath:dirPath]) {

NSError *error;

BOOL isSuccess = [fileManagercreateDirectoryAtPath:dirPath withIntermediateDirectories:YESattributes:nilerror:&error];

if (!isSuccess) {

dirPath = nil;

NSLog(@"error = %@",error.debugDescription);

}

return dirPath;

}

- (void)didReceiveMemoryWarning {

[superdidReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end

新建宏,加强NSLog

// PrefixHeader.pch

// Tank-OS12-01

// Created by ibokan on 15/12/25.

#ifndef PrefixHeader_pch

#define PrefixHeader_pch

// Include any system framework and library headers here that should be included in all compilation units.

// You will also need to set the Prefix Header build setting of one or more of your targets to reference this file.

//A better version of NSLog

#define NSLog(format, ...) do { \

fprintf(stderr, "<%s : %d> %s\n", \

[[[NSString stringWithUTF8String:__FILE__] lastPathComponent] UTF8String], \

__LINE__, __func__); \

(NSLog)((format), ##__VA_ARGS__); \

fprintf(stderr, "-------\n"); \

} while (0)

#endif /* PrefixHeader_pch */

info.plist--->open as ---->source code---->>>第25行加入:

<key>NSAppTransportSecurity</key><dict>        <key>NSAllowsArbitraryLoads</key>        <true/></dict>

用以实现对http协议的访问与读取

新建宏:

在虚拟机显示图片:

断点打印:

0 0

OC语言 系统文件

OC语言系统文件