✔ Marque a linha selecionada em UITableViewCell

Eu sou um novato em desenvolvimento iOS. Quero adicionar uma marca de seleção ao meu UITableViewCellquando ele for selecionado. A marca de seleção deve ser removida quando outra linha for selecionada. Como eu faria isso?

Não use [tableview reloadData]; // é um martelo.

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath   *)indexPath
{
    [tableView cellForRowAtIndexPath:indexPath].accessoryType = UITableViewCellAccessoryCheckmark;
}

-(void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath 
{
    [tableView cellForRowAtIndexPath:indexPath].accessoryType = UITableViewCellAccessoryNone;
}

Em seu método UITableViewDatasource:

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

    if(cell == nil )
    {
        cell =[[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
    }
    if ([indexPath compare:self.lastIndexPath] == NSOrderedSame) 
    {
        cell.accessoryType = UITableViewCellAccessoryCheckmark;
    } 
    else 
    {
        cell.accessoryType = UITableViewCellAccessoryNone;
    }
    return cell;
}

// UITableView Delegate Method
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    self.lastIndexPath = indexPath;

    [tableView reloadData];
}

E lastIndexPath é um property(strong) NSIndexPath* lastIndexPath;

Descobri que recarregar os dados interrompe a animação desmarcada de uma maneira desagradável.

Esta implementação do Swift adiciona / remove claramente as marcas de verificação e desmarca a linha:

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    if self.lastSelection != nil {
        self.myTableView.cellForRowAtIndexPath(self.lastSelection)?.accessoryType = .None
    }

    self.myTableView.cellForRowAtIndexPath(indexPath)?.accessoryType = .Checkmark

    self.lastSelection = indexPath

    self.myTableView.deselectRowAtIndexPath(indexPath, animated: true)
}

onde lastSelectioné declarado comovar lastSelection: NSIndexPath!

Nenhuma atividade extra é cellForRowAtIndexPathnecessária. Não deve ser difícil de replicar em Obj-C.

Para definir uma marca de seleção:

UITableViewCell *cell = ...;
cell.accessoryType = UITableViewCellAccessoryCheckmark;

Para selecionar / desmarcar uma célula:

[cell setSelected:TRUE animated:TRUE]; // select
[cell setSelected:FALSE animated:TRUE]; // deselect

Para desmarcar a célula anterior, use um NSIndexPath * lastSelected ivar para rastrear a última célula selecionada:

- (void)tableView:(UITableView*)tableView didSelectRowAtIndexPath:(NSIndexPath*)indexPath
{
   if (self.lastSelected==indexPath) return; // nothing to do

   // deselect old
   UITableViewCell *old = [self.tableView cellForRowAtIndexPath:self.lastSelected];
   old.accessoryType = UITableViewCellAccessoryNone;
   [old setSelected:FALSE animated:TRUE];

   // select new
   UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
   cell.accessoryType = UITableViewCellAccessoryCheckmark;
   [cell setSelected:TRUE animated:TRUE];

   // keep track of the last selected cell
   self.lastSelected = indexPath;
}

Atualize o Swift 4

  func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.cellForRow(at: indexPath)?.accessoryType = .checkmark
    }

    func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
        tableView.cellForRow(at: indexPath)?.accessoryType = .none
    }

extension ViewController : UITableViewDelegate,UITableViewDataSource {

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.dataArray.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
        cell.textLabel?.text = dataArray[indexPath.row]
        if selectedData.contains(dataArray[indexPath.row]) {
            cell.accessoryType = .checkmark
        }else{
            cell.accessoryType = .none
        }
        return cell
    }


    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

        if selectedData.contains(dataArray[indexPath.row]) {
            selectedData.removeLast()
            tableView.cellForRow(at: indexPath)?.accessoryType = .none
        }else {
            selectedData.removeAll()
            selectedData.append(dataArray[indexPath.row])
            tableView.cellForRow(at: indexPath)?.accessoryType = .checkmark
        }
        print(selectedData)
    }

    func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
        tableView.cellForRow(at: indexPath)?.accessoryType = .none
    }

}

com base na exibição de tabela dataArray formada .. da mesma forma, peguei uma matriz vazia e sempre que o usuário toca em uma célula, com base em indexValue de de dataArray, armazenei esse objeto em selectedDataArray

Quanto à pergunta é como ... Uma pergunta tem várias opções (Respostas), mas no final apenas uma ou nenhuma resposta será um resultado

Da mesma forma, apenas uma célula deve mostrar a marca de seleção e as células restantes devem ser desmarcadas ... em alguns casos, você pode desmarcar sua resposta ... Espero que esta seja a melhor resposta para esta pergunta

Usando Swift 4.2 e swift 5 Código de trabalho da marca de verificação apenas para a linha selecionada em TableView

   func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
    self.tableView.cellForRow(at: indexPath)?.accessoryType = .none
}
   func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    //print(self.coloursArray[indexPath.row])

     self.tableView.cellForRow(at: indexPath)?.accessoryType = .checkmark
}

Supondo que você esteja em uma classe que herda de UITableViewController, isso funciona no Swift 3:

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    // Add a visual cue to indicate that the cell was selected.
    self.tableView.cellForRow(at: indexPath)?.accessoryType = .checkmark
}

override func tableView(_ tableView: UITableView, willSelectRowAt indexPath: IndexPath) -> IndexPath? {
    // Invoked so we can prepare for a change in selection.
    // Remove previous selection, if any.
    if let selectedIndex = self.tableView.indexPathForSelectedRow {
        // Note: Programmatically deslecting does NOT invoke tableView(:didSelectRowAt:), so no risk of infinite loop.
        self.tableView.deselectRow(at: selectedIndex, animated: false)
        // Remove the visual selection indication.
        self.tableView.cellForRow(at: selectedIndex)?.accessoryType = .none
    }
    return indexPath
}

pequeno erro de digitação

// deselect old
UITableViewCell *old = [self.tableView cellForRowAtIndexPath:self.lastSelected];
cell.accessoryType = UITableViewCellAccessoryNone;
[cell setSelected:FALSE animated:TRUE];

deve ler

// deselect old
UITableViewCell *old = [self.tableView cellForRowAtIndexPath:self.lastSelected];
old.accessoryType = UITableViewCellAccessoryNone;
[old setSelected:FALSE animated:TRUE];

e também no

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    if (indexPath.row == [previouslySelected intValue])
    {
        cell.accessoryType = UITableViewCellAccessoryCheckmark;
        selectedIndex = indexPath;
        [cell setSelected:YES animated:YES];
    }
    else
    {
        cell.accessoryType = UITableViewCellAccessoryNone;
        [cell setSelected:NO animated:YES];
    }
} 

onde previamenteSelecionado é seu ivar local, etc. dessa forma, se você recarregar com um índice selecionado, ele também será desmarcado quando você percorrer as seleções possíveis.

As respostas acima não funcionam se você reutilizou a célula para um grande número de dados. Na rolagem, você pode ver a marca de seleção repetida. Para evitar usar as etapas abaixo:

1. declarar na variável: var indexNumber: NSInteger = -1

2. Adicione o código abaixo em cellforRowAtIndexPath:

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell{         
          if indexNumber == indexPath.row{
              cell.accessoryType = .checkmark
          }else{
              cell.accessoryType = .none
          }
   }

3. E em didselectAtIndexpath adicione o código abaixo:

substituir func tableView (_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
            tableView.cellForRow(at: indexPath as IndexPath)?.accessoryType = .checkmark    
indexNumber = indexPath.row
}
override func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
       tableView.cellForRow(at: indexPath as IndexPath)?.accessoryType = .none
}

É melhor enfrentar esse problema de outra direção. Coloque todo o trabalho nos mecanismos UIKit internos e mova a implementação para UITableViewCell:

@implementation MYTableViewCell

- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
    [super setSelected:selected animated:animated];

    self.accessoryType = selected ? UITableViewCellAccessoryCheckmark : UITableViewCellAccessoryNone;
}

- (void)prepareForReuse {
    [super prepareForReuse];
    self.accessoryType = UITableViewCellAccessoryNone;
}

@end

Acho que é mais limpo definir o acessório em sua implementação UITableViewCell personalizada. Em swift, usei:

override func setSelected(_ selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)

    // Configure the view for the selected state
    accessoryType = selected ? .checkmark : .none
}

Apenas chame o didSelectRowAtIndexPathmétodo ao selecionar qualquer linha para Mostrar CheckMark e selecione a linha da marca de seleção para ocultar o CheckMark.

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath: (NSIndexPath *)indexPath {
    [tableView deselectRowAtIndexPath:indexPath animated:true];
    NSLog(@"touch");

    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    if (cell.accessoryType == UITableViewCellAccessoryNone)
    {
       cell.accessoryType = UITableViewCellAccessoryCheckmark;
    }
    else
    {
       cell.accessoryType = UITableViewCellAccessoryNone;
    }
}

swift 4 caso você precise.

var lastSelection: NSIndexPath!
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {


    //CHECK MARK THE CELL
    if self.lastSelection != nil {
        self.tableView.cellForRow(at: self.lastSelection as IndexPath)?.accessoryType = .none
    }

    self.tableView.cellForRow(at: indexPath)?.accessoryType = .checkmark

    self.lastSelection = indexPath as NSIndexPath

    self.tableView.deselectRow(at: indexPath, animated: true)

}

Existem duas maneiras de fazer isso. um é sem várias seleções e outro está com várias seleções.

// Table View Controller -- without Multiple Selection

// Step 1

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

    if(tableView.cellForRow(at: indexPath)?.imageView?.image == UIImage(systemName:"checkmark.circle")) {
         tableView.cellForRow(at: indexPath)?.imageView?.image = UIImage(systemName:"circle")
    } else {
         tableView.cellForRow(at: indexPath)?.imageView?.image = UIImage(systemName:"checkmark.circle")
    }
}

//Step 2

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
    cell.textLabel?.text = employeeValues[indexPath.row]
    cell.imageView?.image = UIImage(systemName:"circle")

    return cell
}

//  Table View Controller -- with Multiple Selection

@IBOutlet var myTableView: UITableView!

override func viewDidLoad() {
    super.viewDidLoad()
    self.myTableView.allowsMultipleSelection = true
}

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
    cell.textLabel?.text = employeeValues[indexPath.row]
    cell.imageView?.image = UIImage(systemName:"circle")

    return cell
}

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

//   let cell = tableView.cellForRow(at: indexPath)?.accessoryType = UITableViewCell.AccessoryType.checkmark

    tableView.cellForRow(at: indexPath)?.imageView?.image = UIImage(systemName:"checkmark.circle")

}

override func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {

    tableView.cellForRow(at: indexPath)?.imageView?.image = UIImage(systemName:"circle")  
}

O código mencionado acima funciona apenas com a seleção única . Este código a seguir certamente funcionará para seleções múltiplas .

- (void)viewDidLoad {
    arrSelectionStatus =[NSMutableArray array]; //arrSelectionStatus holds the cell selection status 
    for (int i=0; i<arrElements.count; i++) { //arrElements holds those elements which will be populated in tableview
        [arrSelectionStatus addObject:[NSNumber numberWithBool:NO]];
    }
}

-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"];

    if (cell==nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"Cell"];
    }

    cell.textLabel.text=[arrElements objectAtIndex:indexPath.row];

    if ([[arrSelectionStatus objectAtIndex:indexPath.row] boolValue] == YES)
        cell.accessoryType = UITableViewCellAccessoryCheckmark;
    else
        cell.accessoryType = UITableViewCellAccessoryNone;

    return cell;
}

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{

    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    cell.accessoryType = UITableViewCellAccessoryCheckmark;

    [arrSelectionStatus replaceObjectAtIndex:indexPath.row withObject:[NSNumber numberWithBool:YES]];
}

-(void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath{
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    cell.accessoryType = UITableViewCellAccessoryNone;

    [arrSelectionStatus replaceObjectAtIndex:indexPath.row withObject:[NSNumber numberWithBool:NO]];
}

Quando uma célula selecionada (com a marca de seleção for selecionada novamente), basta remover a seleção.

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath*)indexPath
{
    BOOL isSelected = ([tableView cellForRowAtIndexPath:indexPath].accessoryType ==  UITableViewCellAccessoryCheckmark);
    if(isSelected){
        [tableView cellForRowAtIndexPath:indexPath].accessoryType = UITableViewCellAccessoryNone;
        [tableView deselectRowAtIndexPath:indexPath animated:YES]; //this won't trigger the didDeselectRowAtIndexPath, but it's always a good idea to remove the selection
    }else{
        [tableView cellForRowAtIndexPath:indexPath].accessoryType = UITableViewCellAccessoryCheckmark;
    }
}

- (void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath*)indexPath
{
    [tableView cellForRowAtIndexPath:indexPath].accessoryType = UITableViewCellAccessoryNone;
}

Bônus:

Use self.tableView.indexPathForSelectedRowpara detectar indexPath para a célula selecionada