在集合视图中显示/隐藏顶部行

Question

I am trying to build login/register page using collection view I want to be able to remove the top 4 rows and shrink the collection view when the user selects the login segment control and i want to re-add these 4 rows and re-size the collection view accordingly. and i want to also be able to maintain the text the user entered in the email textfield when adding-removing these rows. Main Screen

i tried to use the delete items at index path, but couldn't figure out how to re enter them at the top So I tried to use the .ishidden = true instead of deleting but changing the segment control value repeatedly causes the text entered inside the textfield to be placed within different cells. For example if i am on login page with the hidden cells, and i type in Hello in email text field, then i click on Register, the full form is shown, and Hello is the text at Last Name textfield and it keeps appearing within different textfield if i keep on switching between login and register.

The other issue i'm facing, is when i try to make the login screen to look like below Login Screen by changing the collectionView height constraint constant, and setting a minus value for collectionView.contentInset.Top, it does appear as i want it to be, but once i select the Register, it doesn't load the full form and this is how it looks like. partial register

My Code for the segment control change is as below:

@objc func handleLoginRegisterChange() {
        if LoginRegisterSegmentControl.selectedSegmentIndex == 0 {
            LoginRegisterButton.setTitle("Login", for: .normal)
            //collectionView.reloadData()
            collectionView.cellForItem(at: IndexPath(item: 0, section: 0))?.isHidden = true
            collectionView.cellForItem(at: IndexPath(item: 1, section: 0))?.isHidden = true
            collectionView.cellForItem(at: IndexPath(item: 2, section: 0))?.isHidden = true
            collectionView.cellForItem(at: IndexPath(item: 3, section: 0))?.isHidden = true
            collectionView.contentInset.top = -160.6
            collectionViewHeight.constant = 80
        }
        else if LoginRegisterSegmentControl.selectedSegmentIndex == 1 {
            LoginRegisterButton.setTitle("Register", for: .normal)
            collectionView.cellForItem(at: IndexPath(item: 0, section: 0))?.isHidden = false
            collectionView.cellForItem(at: IndexPath(item: 1, section: 0))?.isHidden = false
            collectionView.cellForItem(at: IndexPath(item: 2, section: 0))?.isHidden = false
            collectionView.cellForItem(at: IndexPath(item: 3, section: 0))?.isHidden = false
            collectionView.reloadData()
            collectionView.contentInset.top = 0
            collectionViewHeight.constant = 240
        }
    }

My customCell only have a Textfield

this is how i setup the placeholders

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let customCell = collectionView.dequeueReusableCell(withReuseIdentifier: customeCellIdentifier, for: indexPath) as! CustomCell
    customCell.textField.placeholder = signUpPlaceHolders[indexPath.row]
    return customCell
}

and the signUpPlaceHolder array is :

let signUpPlaceHolders = ["First Name", "Last Name", "Company Name", "Phone", "Email", "Password"]

i am a beginner at Swift and trying to figure out collection Views, your help will be highly appreciated.

Answer 1

I suggest to check the UICollectionView class in Apple doc, then for your example in your segmented control action you could just update your array after declaring it as var:

@objc func handleLoginRegisterChange() {
    if LoginRegisterSegmentControl.selectedSegmentIndex == 0 {    
        signUpPlaceHolders = ["Email", "Password"]
        collectionViewHeight.constant = 80
    } else { 
        signUpPlaceHolders = ["First Name", "Last Name", "Company Name", "Phone", "Email", "Password"]
        collectionViewHeight.constant = 240
    }
    collectionView.reloadData()
}