how to cascade uitableview's width to its custom table view cell? - iphone

I have a certain sized UIView used as a container of a UITableView. I use a subclass of UITableViewCell in my table view.
The problem is that my custom table view cell can not get the proper width from the UITableVIew.
This is how I create the table view
categoryListView = [[UITableView alloc] initWithFrame:categoryListContainer.bounds style:(UITableViewStylePlain)];
This is how I create the custom table view cell.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if (tableView == categoryListView) {
static NSString *CellIdentifier = #"MenuCategoryListIdentifier";
MenuCategoryListCellView *cell = (MenuCategoryListCellView*) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
// create dynamically
cell = [[MenuCategoryListCellView alloc] initWithStyle:(UITableViewCellStyleDefault) reuseIdentifier:CellIdentifier];
}
....
I wish to be able to get the correct cell bounds to in my MenuCategoryListCellView's initWithStyle method to draw my UI controls. But I don't know how to pass the value down.
Help will be appreciated!
Leo

The system will send the layoutSubviews message to your cell when the cell is resized. Override that method to lay out the UI controls according to the cell's current size.

Related

Prototype cells different from dynamically created cells

I have created two types of prototype cells in storyboard. The dimension of one of them have been customized to accomodate UIButton object. However when the cells are created, they have the standard height. I can see the UIButton object but it gets truncated because of the cell height.
Why are the newly created cells different from the prototype cells?
The relevant section of the code is as follows:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell;
if(cell == nil)
{
cell = [tableView dequeueReusableCellWithIdentifier:#"PictureSelectionCell"];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
pictureButtonProperty = (UIButton *) [cell viewWithTag:1];
}
}
Going forward, what are my options for creating the cell of the width (or dimensions) defined in the storyboard? Programmatically, I will be able to achieve this by creating a CGRect object with the specified dimensions and then create a cell using initWithFrame. However, I would like to avoid doing things manually.
Thanks for your response.
first of all you can always set it with code
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return YOUR_ROW_HEIGHT;
}
other way if you choose your UITableView if the storyboard, under the size inspector change the Row Height.

Values are getting cleared from UITableViewCell while scrolling

I have placed three buttons over UITableViewCell and its background is set to an unselect radio button image.
While clicking the button I'm again setting the background image as select button.
In a row one select button should persist but while scrolling UITableView all the selected button images are getting cleared
Can somebody please give me any idea how to do this in this way or in other way ?
You probably are not reusing the cells correctly. When you scroll, a previous cell is reused by the UITableView, but you don't change its contents correctly. Here is a sample code for ur reference
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = #"CellIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:cellIdentifier] autorelease];
}
cell.textLabel.text = [urDataArray objectAtIndex:indexPath.row];
return cell;
}
save the state of you button in table datasource.
set that value to your button. table is reloading each displayed row while scrolling.

Hierarchical UITableview

In my first view I have a UITableView with 5 records. In UITableView cells are holding two different components. One UILabel is text and another UILabel shows value for that cell.
On selection of this UITableViewCell user is navigated to another view where I have given a picker controller for changing the value of 2nd label in the table view for the selected row. I reload the UITableView data on -viewWillAppear but this overlaps the text on lables as many times I visit it.
Can anyone give me relevant example of hierarchical tableview where UItableViewCell's right section is dependant on selection of picker from next view.
I think you are adding the labels on cell.contentView everytime you reload the table, but are not removing the previous ones. Thats why the overlapping is happening.
try to remove the lables
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
for (UIView * view in cell.contentView.subviews) {
[view removeFromSuperview];
view = nil;
}
// add your labels
}

images in tableview cells

Ive added a uiimageview as a subview to my cell.and then put a label on top of it so that it would seem like a button.But whwn the table is scrolled up or down the image seems to get painted again.This turns extremely ugly as my image has transparency effect which is lost as soon as it goes out of view and comes back.???
Ok, I'll try to guess what your code looks like :)
If images are painted multiple times that means you add them each time table view queries data source for a cell:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView #"SomeID"];
if (cell == nil) {
// Create cell
}
UIImageView *imView = ... //Create and initialize view
[cell.contentView addSubview:imView];
...
return cell;
}
So each time your cell appears on screen (after user scrolls the table) new instance of image view is added to the cell. The correct approach is to add image view only once - when cell is created and then obtain and setup the existing image view:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView #"SomeID"];
if (cell == nil) {
// Create cell
UIImageView *imView = ... //Create and initialize view
imView.tag = 1000; // or any other int value
[cell.contentView addSubview:imView];
}
UIImageView *iView = (UIImageView *)[cell.contentView viewWithTag:1000];
iView.image = ...// set required image
...
return cell;
}
So with this approach each time the cell is reused by table view the existing image view is populated with the image appropriate for the current row.
I used a seperate identifier for each cell.
Usually it is not a good idea - in this case table won't be able to reuse its cells and you may get serious performance troubles

UITextView in iphone

i am creating textview(editable) through coding in uitableview in cellforrowatindexpath delegate. textview is showing in every row correctly. the problem is that when i am enter text in textview and scroll the tableview, then text disappear from textview. if anyone has any idea?
When you go to edit the text in the textview, the text scrolls up so that the top of the textview is where the new text will appear when typed. Try swiping down on the textview to reveal the previous info.
Make sure you are adding a different textview to each of the different reusable cells. If you have, say, 6 cells visible at any time, then you need 6 different textviews.
It sounds like when you scroll, your textview gets used for another cell.
// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
MyTableCell *cell = (MyListTableCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:MyIdentifier] autorelease];
cell.textView = [[[UITextView alloc] initWithFrame:/** put appropriate rect here **/] autorelease];
// create other cell structures you need
}
// Set up the cell...
}