iOS应用程序只能在为该改程序创建的文件系统中读取文件，不可以去其它地方访问，此区域被成为沙盒，所以所有的非代码文件都要保存在此，例如图像，图标，声音，映像，属性列表，文本文件等。
沙盒文件的目录结构:
Documents
-
Library
Caches
Preferences
tmp
沙盒下各文件夹保存内容的区别
-
Documents：保存应用运行时生成的
需要持久化的数据，iTunes同步设备时会备份该目录。例如，游戏应用可以将游戏存档保存在该目录下。如果用户将缓存存放在这个文件夹下，会导致应用审核无法通过。 -
tmp：保存应用运行时所需要的
临时数据,使用完毕后再将相应的文件从该目录删除。应用没有运行时，系统也可能会清除该目录下的文件。iTunes同步设备时不会备份该目录。 -
Library/Caches：保存应用运行时生成的
需要持久化的数据，iTunes同步设备时不会备份该目录。一般存储体积大，不需要备份的非重要数据。 -
Library/Preference：保存应用的所有
偏好设置，iOS的Settings(设置)应用会在该目录中查找应用的设置信息。iTunes同步设备时会备份该目录。
获取程序的Home目录
NSString *homeDirectory = NSHomeDirectory();
NSLog(@"path:%@", homeDirectory);
获取document目录
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *path = [paths objectAtIndex:0];
获取Cache目录
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
NSString *path = [paths objectAtIndex:0];
获取Library目录
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);
NSString *path = [paths objectAtIndex:0];
获取Tmp目录
NSString *tmpDir = NSTemporaryDirectory();
NSLog(@"%@", tmpDir);
创建文件夹
-(void)createDirectory{
NSString *documentsPath =[self getDocumentsPath];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *iOSDirectory = [documentsPath stringByAppendingPathComponent:@"/iOS"];
BOOL isSuccess = [fileManager createDirectoryAtPath:iOSDirectory withIntermediateDirectories:YES attributes:nil error:nil];
if (isSuccess) {
NSLog(@"success");
} else {
NSLog(@"fail");
}
}
创建文件
-(void)createFile{
NSString *documentsPath =[self getDocumentsPath];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *iOSPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
BOOL isSuccess = [fileManager createFileAtPath:iOSPath contents:nil attributes:nil];
if (isSuccess) {
NSLog(@"success");
} else {
NSLog(@"fail");
}
}
写文件
-(void)writeFile{
NSString *documentsPath =[self getDocumentsPath];
NSString *iOSPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
NSString *content = @"我要写数据啦";
BOOL isSuccess = [content writeToFile:iOSPath atomically:YES encoding:NSUTF8StringEncoding error:nil];
if (isSuccess) {
NSLog(@"write success");
} else {
NSLog(@"write fail");
}
}
NSString * fileName = @"testFileNSFileManager.txt";
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//获取文件路径
NSString *path = [documentsDirectory stringByAppendingPathComponent:fileName];
//待写入的数据
NSString *temp = @"nihao 世界";
int dataInt = 1234;
float dataFloat = 3.14f;
//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]];
//将其他数据添加到缓冲中
[writer appendBytes:&dataInt length:sizeof(dataInt)];
[writer appendBytes:&dataFloat length:sizeof(dataFloat)];
//将缓冲的数据写入到文件中
[writer writeToFile:path atomically:YES];
读取文件内容
-(void)readFileContent{
NSString *documentsPath =[self getDocumentsPath];
NSString *iOSPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
NSString *content = [NSString stringWithContentsOfFile:iOSPath encoding:NSUTF8StringEncoding error:nil];
NSLog(@"read success: %@",content);
}
//读取数据：
int intData;
float floatData = 0.0;
NSString *stringData;
NSData *reader = [NSData dataWithContentsOfFile:path];
stringData = [[NSString alloc] initWithData:[reader subdataWithRange:NSMakeRange(0, [temp length])]
encoding:NSUTF8StringEncoding];
[reader getBytes:&intData range:NSMakeRange([temp length], sizeof(intData))];
[reader getBytes:&floatData range:NSMakeRange([temp length] + sizeof(intData), sizeof(floatData))];
NSLog(@"stringData:%@ intData:%d floatData:%f", stringData, intData, floatData);
判断文件是否存在
- (BOOL)isSxistAtPath:(NSString *)filePath{
NSFileManager *fileManager = [NSFileManager defaultManager];
BOOL isExist = [fileManager fileExistsAtPath:filePath];
return isExist;
}
计算文件大小
- (unsigned long long)fileSizeAtPath:(NSString *)filePath{
NSFileManager *fileManager = [NSFileManager defaultManager];
BOOL isExist = [fileManager fileExistsAtPath:filePath];
if (isExist){
unsigned long long fileSize = [[fileManager attributesOfItemAtPath:filePath error:nil] fileSize];
return fileSize;
} else {
NSLog(@"file is not exist");
return 0;
}
}
计算整个文件夹中所有文件大小
- (unsigned long long)folderSizeAtPath:(NSString*)folderPath{
NSFileManager *fileManager = [NSFileManager defaultManager];
BOOL isExist = [fileManager fileExistsAtPath:folderPath];
if (isExist){
NSEnumerator *childFileEnumerator = [[fileManager subpathsAtPath:folderPath] objectEnumerator];
unsigned long long folderSize = 0;
NSString *fileName = @"";
while ((fileName = [childFileEnumerator nextObject]) != nil){
NSString* fileAbsolutePath = [folderPath stringByAppendingPathComponent:fileName];
folderSize += [self fileSizeAtPath:fileAbsolutePath];
}
return folderSize / (1024.0 * 1024.0);
} else {
NSLog(@"file is not exist");
return 0;
}
}
删除文件
-(void)deleteFile{
NSString *documentsPath =[self getDocumentsPath];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *iOSPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
BOOL isSuccess = [fileManager removeItemAtPath:iOSPath error:nil];
if (isSuccess) {
NSLog(@"delete success");
}else{
NSLog(@"delete fail");
}
}
移动文件
- (void)moveFileName
{
NSString *documentsPath =[self getDocumentsPath];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *filePath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
NSString *moveToPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
BOOL isSuccess = [fileManager moveItemAtPath:filePath toPath:moveToPath error:nil];
if (isSuccess) {
NSLog(@"rename success");
}else{
NSLog(@"rename fail");
}
}
重命名
- (void)renameFileName
{
//通过移动该文件对文件重命名
NSString *documentsPath =[self getDocumentsPath];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *filePath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
NSString *moveToPath = [documentsPath stringByAppendingPathComponent:@"rename.txt"];
BOOL isSuccess = [fileManager moveItemAtPath:filePath toPath:moveToPath error:nil];
if (isSuccess) {
NSLog(@"rename success");
}else{
NSLog(@"rename fail");
}
}
