我正在使用AFNetworking从
JSON提要加载图像.
在这里,用户第一次打开应用程序时,图像会从互联网上加载.没关系.
但是当用户返回并从另一个视图再次使用时,图像应该从缓存加载,而不是从互联网加载.
我怎样才能做到这一点?
- (void)loadDetailData
{
detailPost = nil;
NSString *detailUrl = [NSString stringWithFormat:@"%@", self.Details.firsturl];
AFHTTPRequestOperationManager *detailManager = [AFHTTPRequestOperationManager manager];
[detailManager GET:detailUrl parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
detailPosts = (NSDictionary *)responseObject;
detailPost = [NSMutableArray array];
NSArray *result = [detailPosts objectForKey:@"posts"];
for (NSDictionary *all in result)
{
Categories *newCategory = [Categories new];
NSDictionary *thumbnail_images = [all objectForKey:@"thumbnail_images"];
NSDictionary *mediumImages = [thumbnail_images objectForKey:@"medium"];
newCategory.detailimageUrl = [mediumImages objectForKey:@"url"];
newCategory.title = [all objectForKey:@"title"];
newCategory.mogowebUrl = [all objectForKey:@"url"];
// NSLog(@"%@", newCategory.title);
[detailPost addObject:newCategory];
[self.maintableView reloadData];
}
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
}];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [detailPost count];;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
FirstTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"reuseIdentifier"];
Categories *details = [detailPost objectAtIndex:indexPath.row];
cell.detailTitle.text = details.title;
NSString *imageurl = [NSString stringWithFormat:@"%@", details.detailimageUrl];
NSURL *imgurl = [NSURL URLWithString:imageurl];
[cell.detailImageView setImageWithURL:imgurl placeholderImage:nil];
// [cell addSubview:cell.subView];
cell.layer.masksToBounds = NO;
cell.layer.cornerRadius = 5;
cell.layer.borderColor = [UIColor blackColor].CGColor;
cell.layer.shadowOffset = CGSizeMake(0, 1);
cell.layer.shadowRadius = 2.0;
cell.layer.shadowColor = [UIColor lightGrayColor].CGColor;
return cell;
}
最佳答案 TL;博士
使用-setImageWithURLRequest:placeholderImage:success:failure:
NSURLRequest *imageRequest =
[NSURLRequest requestWithURL:[NSURL URLWithString:imgurl]
cachePolicy:NSURLRequestReturnCacheDataElseLoad
timeoutInterval:60];
[cell.detailImageView setImageWithURLRequest:imageRequest
placeholderImage:nil
success:nil
failure:nil];
图像缓存AFNetworking
导入UIImageView AFNetworking标题和中提琴! UIImageView类现在有几种方法可以下载图像,也可以缓存它们!
内存中缓存:您可以使用以下方法进行简单的内存缓存.
> – setImageWithURL:
> – setImageWithURL:placeholderImage:
如果图像存在,将从内存缓存中检索图像,否则将从URL下载并存储在内存缓存中.
例:
[imageView setImageWithURL:[NSURL URLWithString:imageURL]];
//here, placeholder image is set immediately.
[imageView setImageWithURL:[NSURL URLWithString:imageURL]
placeholderImage:[UIImage imageNamed:@"placeholder.png"]];
磁盘缓存:如果需要将图像缓存的时间超过用户的会话,则可以使用以下方法. (提示:检查NSURLRequest类中的NSURLRequestCachePolicy)
> -setImageWithURLRequest:placeholderImage:success:failure:
注意:如果指定了成功块,则块的责任是在返回之前设置图像视图的图像.如果未指定成功块,则应用使用self.image = image设置图像的默认行为.
例:
NSURLRequest *imageRequest =
[NSURLRequest requestWithURL:[NSURL URLWithString:imageURL]
cachePolicy:NSURLRequestReturnCacheDataElseLoad
timeoutInterval:60];
[imageView setImageWithURLRequest:imageRequest
placeholderImage:[UIImage imageNamed:@"placeholder.png"]
success:nil
failure:nil];