UITableVIew中的自定义单元格外观

Question

i was following this torturial:

http://www.raywenderlich.com/32283/core-graphics-tutorial-lines-rectangles-and-gradients

It covers customization of dynamic table cells, i need to do it with static table cells.

I have given every cell the identifier "Cell", as he does in the tutorial, i then subclassed the table view controller and implemented this:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString * CellIdentifier = @"Cell";
    UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];


    // START NEW
    if (![cell.backgroundView isKindOfClass:[CostumCellBackground class]]) {
        cell.backgroundView = [[CostumCellBackground alloc] init];
    }


    if (![cell.selectedBackgroundView isKindOfClass:[CostumCellBackground class]]) {
        cell.selectedBackgroundView = [[CostumCellBackground alloc] init];
    }
    // END NEW


    cell.textLabel.backgroundColor = [UIColor clearColor]; // NEW

    return cell;
}

CostumCellBackground draws the rect.

I am getting the error "UITableView dataSource must return a cell from tableView:cellForRowAtIndexPath:

As far as i understand UITableView is looped for every Cell in the storyboard, and it is supposed to return cell.

So, whats going on here and why does the cell return nil, or doesnt return at all ?

The only difference is that they are static tables, and not prototypes.

Answer 1

If you are using Storyboards and iOS6 and your view controller is a UITableViewController, you will always get a cell if your cell identifier is present in your storyboard. Checking for cel == nil is the old way to do it.

Are you sure you have a custom cell in your storyboard with the "Cell" identifier?

Also, use this:

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

If you look in the UITableView.h file you will find:

// newer dequeue method guarantees a cell is returned and resized properly, assuming identifier is registered
- (id)dequeueReusableCellWithIdentifier:(NSString *)identifier forIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(6_0); 

Answer 2

Where is you create your cell ??

You should add after:

UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

such code (or something another initializer):

if (cell == nil) {
    cell = [[UITableViewCell alloc] init];   
}

Answer 3

Try this at the beginning of your method:

- (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
                ];
    }