iOS笔记之文件读写

- (void)savePhotos:(NSArray *)photos {

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *plistPath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"photo_info.plist"];
NSString *filePath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"Image"];
NSLog(@"%@", filePath);

NSFileManager* fileManager = [NSFileManager defaultManager];
if (![fileManager fileExistsAtPath:plistPath]) {
[fileManager createFileAtPath:plistPath contents:nil attributes:nil];
}
if (![fileManager fileExistsAtPath:filePath]) {
[fileManager createDirectoryAtPath:filePath withIntermediateDirectories:NO attributes:nil error:nil];
}

NSMutableArray *savePhotos = [[NSMutableArray alloc] init];

for (Photo *photo in photos) {
NSMutableDictionary *info = [[NSMutableDictionary alloc]init];

NSString *imagePath = [filePath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.jpg", photo.name]];
[UIImagePNGRepresentation(photo.image)writeToFile:imagePath atomically:YES];
[info setObject:imagePath forKey:@"ImagePath"];
[info setObject:photo.name forKey:@"Name"];
[info setObject:photo.tags forKey:@"Tags"];
[info setObject:photo.date forKey:@"Date"];

[savePhotos addObject:info];
}
[savePhotos writeToFile:plistPath atomically:YES];
}

- (NSArray *)loadPhotosFromDisk {
//从本地读取图片
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *plistPath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"photo_info.plist"];

NSArray *photosArr = [NSArray arrayWithContentsOfFile:plistPath];
for (NSDictionary *dic in photosArr) {
Photo *photo = [[Photo alloc] init];
photo.image = [UIImage imageWithContentsOfFile:[dic valueForKey:@"ImagePath"]];
photo.name = [dic valueForKey:@"Name"];
photo.tags = [dic valueForKey:@"Tags"];
photo.date = [dic valueForKey:@"Date"];
[self.photos addObject:photo];
}

return self.photos;
}