更改UITableView中一些选定的表格视图单元格文本的颜色

Question

I have a table view with 8 cells. Each contain a label. For the last 4 cells I want the label's text property to have a blue color. For the first four cells I want them to have a black color.

I set the text color to blue in cellForRowAt indexPath with the following code:

if indexPath.row > 4 {
    cell.label.textColor = UIColor.blue
}

This changes the color to blue, but when the user scrolls down and then up again the first two cell labels also have a blue color, because the cells got reused.

How can I solve this? Thanks.

Answer 1

You will have to add else part into your cellForRow method since the dequeuing problem or Cell Reuse Issue.

cell.label.textColor = indexPath.row > 4 ? .blue : .black

Note: Always remember to add else part into cellForRow Method, Otherwise it behaves weirdly.

Answer 2

First, your code in its current state sets the color of all the cells whose indexes are greater than 4 to blue , not only the last 4 cells. You need to change your condition.

And after that, you need to add an else statement to handle other cells color, the cells who do not fulfill the condition. This is because the cells are reused, so they always need to have their color set.

So your code should look something like this:

if indexPath.row > numberOfRows - 4 {
    cell.label.textColor = .blue
} else {
    cell.label.textColor = .black
}

Or as mentioned by @jarvis, you can use ternary operator to make your code more compact, like this:

cell.label.textColor = indexPath.row > numberOfRows - 4 ? .blue : .black

numberOfRows is the number of rows the table view has.

Answer 3

You need to set else condition too so that it won't change

if indexPath.row > 4 {
    cell.label.textColor = UIColor.blue
}
else {
    cell.label.textColor = UIColor.black
}

Answer 4

That's because because indeed the cell is being reused. To solve that, you need a logic what to do with the cells/rows not satisfying your condition indexPath.row > 4 . :)

Answer 5

That's because because indeed the cell is being reused.

Make sure to use else condition everytime in UITableView and UICollectionView so value will not interchange during scroalling.

Here is 2 method you can follow so that color will not interchange.

cell.label.textColor = indexPath.row > 4 ? .blue : .black

OR

if indexPath.row > 4 {
    cell.label.textColor = UIColor.blue
}
else {
    cell.label.textColor = UIColor.black
}