How to hide a static UITableViewCell? - ios

How do you hide a static cell?
I would like to hide and static cell if an image does not exist.
I tried:
imageCell.hidden = YES; //did not work
I have seen answers suggesting to change datasource or use:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 0;// will hide all cell
}
But I couldnt find a way to do this with a specific view cell.
what I want to achieve:
if(image==nil){
//hide imageCell
}
Now here is the catch , the image is downloaded asynchronously, so deleguate methods might be called before the attempted downlaod.

Do the following :
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.row == 2 && !myImageIsLoaded)
return 0; // Will hide just the third row of your table if myImageIsLoaded is false
return 44;
}
And you can use the following to animate all whenever you want (e.g. each time an image as loaded) :
[myTable beginUpdate];
[myTable endUpdate];
If your cells are static so it should work. Otherwise you could encounter some problems.

If you want literally hide the cell that image does not exist, you can try this:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
return [cell imageView] ? 44.0f : 0.0f;
}

Related

Issue While Finding Height of UITableViewCell

I am calculating height of Cell programatically in heightForRowAtIndexPath-
My complete method is:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
id cell = [self.tableView dequeueReusableCellWithIdentifier:kCellID];
if([cell isKindOfClass:[Custom class]])
{
return 100;
}
else
{
return 20;
}
}
My app takes 3-5 sec to Show the ViewController. Although cellForRowAtIndexPath is called and I can show the logs in Console.
But My ViewController not loaded.
When just return the height using this code app works fine:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
return 100;
}
I don't know that is the issue with this line:
id cell = [self.tableView dequeueReusableCellWithIdentifier:kCellID];
What I am missing in this issue?
You have some logic in the cellForRowAtIndexPath: method that determines what type of cell that row should be. Add that logic into the heightForRowAtIndexPath: method to determine the what the height of each row should be.
Your this line is wrong
id cell = [self.tableView dequeueReusableCellWithIdentifier:kCellID];
it will force your cell to reuse.
Use
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
id cell=[tableView cellForRowAtIndexPath:indexPath];
if([cell isKindOfClass:[CustomCellClass class]])
{
return 100;
}
else
{
return 20;
}
}

Using Multiple UITableViewCells for one tableView

I am unsure if I'm setting up the UITableView the right way when using multiple custom cell views. I seem to have my table working however, i think the reuse of cells makes the first cells you see once you load the view the same size as the very first cell which should be the only cell thats double in size. Once I scroll passed them and back up they go to the size thats set for them.
Is there a right way of doing this? I've looked through other forms and tried their ways but this is the closed I've gotten it to work with just that one flaw.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier1 = #"profileCell";
static NSString *CellIdentifier2 = #"profileCells";
if (indexPath.section == 0) {
PFProfileTableCellView * cell = (PFProfileTableCellView *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier1];
//only one row in this section
return cell;
} else{
PFWallPostTableViewCell * cell = (PFWallPostTableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier2];
return cell;
}
}
Use this UITableView delegate method - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath; and return row height according to the sections of your tableview like the example below
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.section == 0) {
return 100.0;
}
return 50.0;
}

UITableView Custom Cells Overlapping

Starting my quest into ios development but I have a problem, below.
The plan:
The result:
You need to set height of your custom cell using tableview delegate method
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.row == 0) {
return 150.0;
}else if (indexPath.row == 1){
return 300.0;
}
return 0.0;
}
as well as u need to set your custom cell cliptobound property to yes in datasource method
- (CGFloat)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
customcell *cell = (customcell *)[tableView dequeResusableCellWithIdentifier:#"newcell" forIndexPath:indexPath];
cell.cliptobound = YES;
return cell;
}
Your tableview needs to know the height of your custom cell, use the following tableview delegate method:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.row == 0) {
return 100.0;
}
return 200.0;
}
Your cells are getting reused without the content being reset in cellForRowAtIndexPath. In that method you need to blank out the cell content before putting more content in it.

Reduced cell in grouped UITableview

I am adding one more section to the existing tableView and getting this:
my new cell is reduced by height. Appropriate methods:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
return cells[indexPath.section][indexPath.row];
}
- (CGFloat) tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
if ([headers[section] isKindOfClass:[UIView class]])
return [headers[section] frame].size.height;
return 10.0f;
}
- (UIView *) tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
if ([headers[section] isKindOfClass:[UIView class]])
return headers[section];
return nil;
}
- (CGFloat) tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = cells[indexPath.section][indexPath.row];
if (cell == clientXibCell) return 100.0f;
if (cell == agencyXibCell) return 145.0f;
return 46.0f;
}
I can't understand what I need to do to fix this. Any ideas where the source of issue can be?
Update
I am now sure that predefining custom cell visual interface making this trouble.
supervisorCell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:nil];
bgView = [[UIImageView alloc] initWithFrame:supervisorCell.backgroundView.frame];
[bgView setImage:stretchableImageByHorizontal([UIImage imageNamed:#"cell_bgd_bottom"])];
[supervisorCell setBackgroundView:bgView];
bgView = [[UIImageView alloc] initWithFrame:supervisorCell.backgroundView.frame];
[bgView setImage:stretchableImageByHorizontal([UIImage imageNamed:#"cell_bgd_bottom_active"])];
[supervisorCell setSelectedBackgroundView:bgView];
When I am uncommenting everything except first statement of creating the cell, everything works fine except custom appearance of cell. What do I need to change in this simple code to fix this?
The height of your cells are controlled by the heightForRowAtIndexPath:. Taking a look on your code, it seems that this method is always returning 46.
Your two ifs are comparing pointers, i. e., instancies of your cells. It means that of all your cells, one will have the height 100, one 145 and all others 46.f.
I think what are you trying to accomplish is set this height for all cells of the same kind, so you should change your heightForRowAtIndexPath: method, like below:
- (CGFloat) tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
if ( [cell isKindOfClass:[YourCustomCell1 class]] ) return 100.0f;
if ( [cell isKindOfClass:[YourCustomCell2 class]] ) return 145.0f;
return 46.0f;
}
Ps1: Change YourCustomCell class for your own classes. If you don't have subclasses, try to set tags or something like that to differentiate them.
Ps2: always use tableview's method cellForRowAtIndexPath to get the reference of the cell by the indexPath.

UITableView in UICollectionViewCell

I have a UICollectionView whose all cells contains a UITableView. My UICollectionView delegate / datasource methods are handled by a view controller (let's say TTCollectionViewController), and tableViews are handled directly by collection view cells (TTCollectionViewCell).
In order to change some label colors, I need to keep track of each selected rows on my tableViews so i did something like that :
//
// TTCollectionViewCell.m
//
[...]
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// keep track of selected drugs
if (![self.selectedDrugIndexPaths containsObject:indexPath])
{
[self.selectedDrugIndexPaths addObject:indexPath];
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
TTTableViewCell *contentCell = [tableView dequeueReusableCellWithIdentifier:#"test"];
if (contentCell == nil)
contentCell = [[TTTableViewCell alloc] init];
[...]
// test
if ([self.selectedDrugIndexPaths containsObject:indexPath]) {
contentCell.drugLabel.textColor = [UIColor grayColor];
} else {
contentCell.drugLabel.textColor = [UIColor blackColor];
}
}
[...]
But here's the thing : with the dequeue reusable thing, my collectionView is messing up all my tracks (on scrolling, selected rows on table 1 become selected on table 3 for example).
I know it's a bad idea to don't use dequeuereusable (i don't even know if it's possible to not use it), but is there something similar that i can do ?
Do anyone have already implement this kind of case ?
Thx in advance.
EDIT :
Here's my cellForRow... methods of my collectionView as you asked for :
///
/// TTCollectionController.m
///
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
TTCollectionCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"cell" forIndexPath:indexPath];
cell.data = [self.data objectAtIndex:indexPath.row];
return cell;
}

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