PFQueryTableView 在新数据更新时自动刷新或使用 Parse 每分钟刷新一次 [英] PFQueryTableView Auto Refresh When New Data Updated or Refresh Every Minute Using Parse
问题描述
目前我正在关注本教程 http://www.appcoda.com/ios-programming-app-backend-parse/
Currently Im following this tutorial http://www.appcoda.com/ios-programming-app-backend-parse/
但是当来自 parse.com 的数据自动更新时,我希望 tableviewcontroller 用新数据刷新.我不希望用户总是需要拉来刷新.
But I want the tableviewcontroller to be refresh with new data when data from parse.com is update automatically. I don't want the user to always have to pull to refresh.
或者每分钟刷新一次时间?
or maybe having time refresh every minute?
我听说过 reloaddata 但如何实现代码?
I heard about reloaddata but how to implement the code?
- (id)initWithCoder:(NSCoder *)aCoder
{
self = [super initWithCoder:aCoder];
if (self) {
// The className to query on
self.parseClassName = @"Recipe";
// The key of the PFObject to display in the label of the default cell style
self.textKey = @"name";
// Whether the built-in pull-to-refresh is enabled
self.pullToRefreshEnabled = YES;
// Whether the built-in pagination is enabled
self.paginationEnabled = NO;
}
return self;
}
- (PFQuery *)queryForTable
{
PFQuery *query = [PFQuery queryWithClassName:self.parseClassName];
return query;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath object:(PFObject *)object
{
static NSString *simpleTableIdentifier = @"RecipeCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
}
// Configure the cell
PFFile *thumbnail = [object objectForKey:@"imageFile"];
PFImageView *thumbnailImageView = (PFImageView*)[cell viewWithTag:100];
thumbnailImageView.image = [UIImage imageNamed:@"placeholder.jpg"];
thumbnailImageView.file = thumbnail;
[thumbnailImageView loadInBackground];
UILabel *nameLabel = (UILabel*) [cell viewWithTag:101];
nameLabel.text = [object objectForKey:@"name"];
UILabel *prepTimeLabel = (UILabel*) [cell viewWithTag:102];
prepTimeLabel.text = [object objectForKey:@"prepTime"];
return cell;
}
推荐答案
在 .h 文件中
@property (nonatomic, strong) NSTimer *fetchTimer;
@property (nonatomic, strong) NSArray *items;
在 .m 文件中
- (void)viewDidLoad
{
NSTimer *timer = [NSTimer timerWithTimeInterval:3600
target:(id)self
selector:@selector(fetch)
userInfo:nil
repeats:YES];
self.fetchTimer = timer;
}
- (void)fetch
{
PFQuery *query = [PFObject query];
[query whereKey:@"" equalTo:@""];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
self.items = [NSArray arrayWithArray:objects];
[self.tableView reloadData];
}];
}
1) 设置一个间隔时间为 3600 的 NSTimer 并触发获取数据功能.2) 取数据后调用 [self.tableView reloadData] 即可.这完全取决于您如何设计编码结构.
1) Set a NSTimer with 3600 intervalTime and trigger the fetch data function. 2) Just call [self.tableView reloadData] when the data has been fetch. It is all depends on how you design your coding structure.
这篇关于PFQueryTableView 在新数据更新时自动刷新或使用 Parse 每分钟刷新一次的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!