iPhone - Create custom UITableViewCell top and bottom borders

问题

I have been looking everywhere and have not quite found my answer.

I populating a UITableView with dynamic cells from JSON and I am trying to hide any extra cells. I turned off the separators in IB, and of course all the cell separators disappear. How do I add a line to the bottom and top of each tableviewcell so that only the cells that have information show a border? I have imported Quartz and have been playing with CALayer but can't find a solution.

I found a similar question here, but the only answer was not very helpful.

What would be a better, different way of doing this?

Here are my cellForRowAtIndexPath and my numberOfRowsInSection:

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{

    // Return the number of rows in the section.
    //set equal to the information in the array

    return [_jsonDataArray count];
}

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

    //create Dictionary of data in row
    NSDictionary *jsoninfo = [_jsonDataArray objectAtIndex:indexPath.row];

    //get required keys from dictionary and assign to vairables
    NSString *title = [jsoninfo objectForKey:@"title"];
    NSString *subtitle = [jsoninfo objectForKey:@"subtitle"];
    NSURL *imageURL = [NSURL URLWithString:[jsoninfo objectForKey:@"series_image_URL"]];

    //download the images.
    NSData *imgData = [NSData dataWithContentsOfURL:imageURL];
    UIImage *img = [[UIImage alloc] initWithData:imgData];


    //set boarder for custom cells... I need to have a border on the top and bottom of the cells I am creating so xcode does not autofill the empty space.



    //fill in text to cells
    cell.textLabel.text = title;
    cell.detailTextLabel.text = subtitle;
    cell.imageView.image = img;

    return cell;
}

回答1:

I also think it's not the best idea, but if you really want to do this, here's code that will achieve what you want:

tableView.separatorStyle = UITableViewCellSeparatorStyleNone;

// Draw top border only on first cell
if (indexPath.row == 0) {
    UIView *topLineView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 1)];
    topLineView.backgroundColor = [UIColor grayColor];
    [cell.contentView addSubview:topLineView];
}

UIView *bottomLineView = [[UIView alloc] initWithFrame:CGRectMake(0, cell.bounds.size.height, self.view.bounds.size.width, 1)];
bottomLineView.backgroundColor = [UIColor grayColor];
[cell.contentView addSubview:bottomLineView];

Put this code in the tableView:cellForRowAtIndexPath: method. The final look of your UITableView will be like this:

Take into account that this is not very good for performance, especially if you have a lot of cells. If you have a bigger amount of data, refer to this SO question for help on how to optimize the drawing.

回答2:

Only try this at tableView:cellForRowAtIndexPath: method

[cell.contentView.layer setBorderColor:[UIColor grayColor].CGColor];
[cell.contentView.layer setBorderWidth:1.0f];

回答3:

It sounds like a sub-optimal solution to try to "distinguish" your valid cells from empty ones with lines. A superior approach would be to clean up the data source before populating the table with it.

回答4:

Use Custom Cells. Your Datasoure (Models) should drive the information into the Custom Cells. Create a setter within the Custom Cell class that can be set at each row. as in....

---

1. Allocation your Custom Cell with reuse Id,

2. Pass the property that is determing if the line should show:
   [cell setCustomLines:Model.property];

3. return the cell;

---

You will have far more flexibility to design the CustomCell any way you want, Images, Lines, Colors, or other ways of letting your user's see a difference among your cells.

Technically, Marco's Answer will work, and good job on a simple solution. But you will not be able to expand this very much farther this this.

回答5:

This is not the answer to the question, but the clean solution for the original problem.

Add an empty UIView as the footer of the UITableView. Then the empty cells will be hidden. See this answer.

来源：https://stackoverflow.com/questions/13980960/iphone-create-custom-uitableviewcell-top-and-bottom-borders