我在使用Parse作为后端时在表格单元格中实现类似按钮的按钮时遇到了麻烦。 tablecell中有一个按钮,使用发送者/标签调用。这是代码。
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"FeedCell";
FeedCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[FeedCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
PFObject *post = [postArray objectAtIndex:indexPath.row];
cell.likeForYa.tag = indexPath.row;
[cell.likeForYa addTarget:self
action:@selector(aMethod:) forControlEvents:UIControlEventTouchUpInside];
}
在发件人无效,这是代码:
-(void)aMethod:(id)sender {
UIButton *senderButton = (UIButton *)sender;
NSLog(@"current Row=%d",senderButton.tag);
PFObject *tempObject = [postArray objectAtIndex:senderButton.tag];
NSLog(@"%@", tempObject.objectId);
//add the object ID for the cell we are liking to the array of liked items in the user class in parse
[[PFUser currentUser]addUniqueObject:tempObject.objectId forKey:@"liked"];
[[PFUser currentUser] saveInBackground];
PFObject* like = [PFObject objectWithClassName:@"Like"];
[like setObject:[PFUser currentUser][@"username"] forKey:@"username"];
[like setObject:tempObject.objectId forKey:@"photo"];
[like saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
PFQuery *query = [PFQuery queryWithClassName:@"Like"];
[query whereKey:@"photo" equalTo:tempObject.objectId];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
NSLog(@"Number: %lu", (unsigned long)objects.count);
//cell.lik.text = [NSString stringWithFormat:@"%lu",(unsigned long)objects.count];
}];
}];
}
单击按钮时,没有任何内容存储,objects.count的日志返回0.任何想法?
答案 0 :(得分:1)
所以在这里你使用PFQueryTableViewController进行子类化,你的tableViewCell看起来像这样:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath object:(PFObject *)object {
static NSString *CellIdentifier = @"FeedCell";
FeedCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[FeedCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
UIButton *likeForYa = [UIButton buttonWithType:UIButtonTypeCustom];
[likeForYa setTag:CellLikeForYaTag];
[cell.contentView addSubview:likeForYa];
[likeForYa addTarget:self
action:@selector(aMethod:)
forControlEvents:UIControlEventTouchUpInside];
}
UIButton * likeForYa = (UIButton*) [cell.contentView viewWithTag:CellLikeForYaTag];
// check if current user like the post and change like-button image accordingly
if ([[object objectForKey:@"whoLiked"]containsObject:[PFUser currentUser].objectId]) {
[likeForYa setImage:[UIImage imageNamed:@"pressedLike.png"] forState:UIControlStateNormal];
} else {
[likeForYa setImage:[UIImage imageNamed:@"unpressedLike.png"] forState:UIControlStateNormal];
}
}
这是aMethod:
- (void)aMethod:(UIButton *)button{
CGPoint hitPoint = [button convertPoint:CGPointZero toView:self.tableView];
NSIndexPath *hitIndex = [self.tableView indexPathForRowAtPoint:hitPoint];
PFObject *object = [self.objects objectAtIndex:hitIndex.row];
// check if current user already liked the post
if (![[object objectForKey:@"whoLiked"]containsObject:[PFUser currentUser].objectId]) {
//add the object ID for the cell we are liking to the array of liked items in the user class in parse
[[PFUser currentUser] addUniqueObject:object.objectId forKey:@"liked"];
[[PFUser currentUser] saveInBackground];
//add the user ID to the post that the user liked
[object addUniqueObject:[PFUser currentUser].objectId forKey:@"whoLiked"];
[object saveInBackground];
} else {
//remove the object ID for the cell we are liking to the array of liked items in the user class in parse
[[PFUser currentUser] removeObject:object.objectId forKey:@"liked"];
[[PFUser currentUser] saveInBackground];
//remove the user ID to the post that the user liked
[object removeObject:[PFUser currentUser].objectId forKey:@"whoLiked"];
[object saveInBackground];
}
[self.tableView reloadData];
}
答案 1 :(得分:0)
总是意识到抛出错误的结果。
PFObject* like = [PFObject objectWithClassName:@"Like"];
[like setObject:[PFUser currentUser][@"username"] forKey:@"username"];
[like setObject:tempObject.objectId forKey:@"photo"];
[like saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
//1. Check isSuccess
if (succeeded) {
PFQuery *query = [PFQuery queryWithClassName:@"Like"];
[query whereKey:@"photo" equalTo:tempObject.objectId];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (error == nil) {
NSLog(@"Number: %lu", (unsigned long)objects.count);
//cell.lik.text = [NSString stringWithFormat:@"%lu",(unsigned long)objects.count];
}
}];
}
}];
另一件事是确保parse.com中的DataTable / Class / Object Structure与名称匹配,并键入您在此处传递的内容。
就像
"像"具有字段"用户名"的类它的类型为String。并且"照片"类型相同的(tempObject.objectId)。