Question

我有一个基于视图的应用程序，我将tableview作为子视图添加到主视图中。我已经采用UITableViewDelegate来响应表方法。一切正常，但我想选择第一行或UITableView作为默认选择（突出显示）。

请帮助我，用我需要的代码以及我需要的代码。

Answer 1

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    NSIndexPath *indexPath=[NSIndexPath indexPathForRow:0 inSection:0];
    [myTableView selectRowAtIndexPath:indexPath animated:YES  scrollPosition:UITableViewScrollPositionBottom];
}

在代码中使用它的最佳方法是，如果要在默认情况下选择任何行，请在viewDidAppear中使用。

Answer 2

Swit 3.0更新解决方案

let indexPath = IndexPath(row: 0, section: 0)
tblView.selectRow(at: indexPath, animated: true, scrollPosition: .bottom)

Answer 3

- (void)viewWillAppear:(BOOL)animated
    {

       [super viewWillAppear:animated];

     // assuming you had the table view wired to IBOutlet myTableView

        // and that you wanted to select the first item in the first section

        [myTableView selectRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0] animated:NO scrollPosition:0];
    }

Answer 4

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.detailViewController = (DetailViewController *)[[self.splitViewController.viewControllers lastObject] topViewController];

    if([UIDevice currentDevice].userInterfaceIdiom == UIUserInterfaceIdiomPad){
        NSIndexPath* indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
        [self.tableView selectRowAtIndexPath:indexPath animated:NO scrollPosition:UITableViewScrollPositionTop];
        [self tableView:self.tableView didSelectRowAtIndexPath:indexPath];
    }
}

Answer 5

以下是如何在Swift 1.2中执行此操作：

override func viewWillAppear(animated: Bool) {
    let firstIndexPath = NSIndexPath(forRow: 0, inSection: 0)
    self.tableView.selectRowAtIndexPath(firstIndexPath, animated: true, scrollPosition: .Top)
}

Answer 6

Swift 4更新：

func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    let indexPath = IndexPath(row: 0, section: 0)
    myTableView.selectRow(at: indexPath, animated: true, scrollPosition: .bottom)
}

如果要选择其他部分中的任何其他行，请更改行和部分值。

Answer 7

Swift 5.x更新：

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    let indexPath = IndexPath(row: 0, section: 0)
    tableView.selectRow(at: indexPath, animated: true, scrollPosition: .bottom)
    tableView.delegate?.tableView?(tableView, didSelectRowAt: indexPath)
}

这对我有用，希望对您有帮助。

快乐编码：）

Answer 8

要仅在第一次加载表时选择第一个单元格，可以认为使用viewDidLoad是正确的选择，但，在执行时， table没有加载其内容，所以它不起作用（可能会崩溃应用程序，因为NSIndexPath将指向一个不存在的单元格。）

解决方法是使用一个变量来指示表之前已加载并相应地执行工作。

@implementation MyClass {
    BOOL _tableHasBeenShownAtLeastOnce;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    _tableHasBeenShownAtLeastOnce = NO; // Only on first run
}

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

    if ( ! _tableHasBeenShownAtLeastOnce )
    {
        _tableHasBeenShownAtLeastOnce = YES;
        BOOL animationEnabledForInitialFirstRowSelect = YES; // Whether to animate the selection of the first row or not... in viewDidAppear:, it should be YES (to "smooth" it). If you use this same technique in viewWillAppear: then "YES" has no point, since the view hasn't appeared yet.
        NSIndexPath *indexPathForFirstRow = [NSIndexPath indexPathForRow:0 inSection: 0];

        [self.tableView selectRowAtIndexPath:indexPathForFirstRow animated:animationEnabledForInitialFirstRowSelect scrollPosition:UITableViewScrollPositionTop];
    }
}

/* More Objective-C... */

@end

Answer 9

这是我对swift 3.0的解决方案：

var selectedDefaultIndexPath = false


override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    if dataSource.isEmpty == false, selectedDefaultIndexPath == false {
        let indexPath = IndexPath(row: 0, section: 0)
        // if have not this, cell.backgroundView will nil.
        tableView.selectRow(at: indexPath, animated: false, scrollPosition: .none)
        // trigger delegate to do something.
        _ = tableView.delegate?.tableView?(tableView, willSelectRowAt: indexPath)
        selectedDefaultIndexPath = true
    }
}

func tableView(_ tableView: UITableView, willSelectRowAt indexPath: IndexPath) -> IndexPath? {
    let cell = tableView.cellForRow(at: indexPath)
    cell?.selectedBackgroundView?.backgroundColor = UIColor(hexString: "#F0F0F0")

    return indexPath
}

Answer 10

我们根据细胞是第一个细胞......中间细胞还是最后一个细胞，为细胞使用自定义背景图像。这样我们就可以获得整个表格的圆角。当选择该行时，它会交换出一个漂亮的“突出显示”单元格，以便用户反馈他们已经选择了一个单元格。

UIImage *rowBackground;
UIImage *selectionBackground;
NSInteger sectionRows = [tableView numberOfRowsInSection:[indexPath section]];
NSInteger row = [indexPath row];

if (row == 0 && row == sectionRows - 1)
{
    rowBackground = [UIImage imageNamed:@"topAndBottomRow.png"];
    selectionBackground = [UIImage imageNamed:@"topAndBottomRowSelected.png"];
}
else if (row == 0)
{
    rowBackground = [UIImage imageNamed:@"topRow.png"];
    selectionBackground = [UIImage imageNamed:@"topRowSelected.png"];
}
else if (row == sectionRows - 1)
{
    rowBackground = [UIImage imageNamed:@"bottomRow.png"];
    selectionBackground = [UIImage imageNamed:@"bottomRowSelected.png"];
}
else
{
    rowBackground = [UIImage imageNamed:@"middleRow.png"];
    selectionBackground = [UIImage imageNamed:@"middleRowSelected.png"];
}


((UIImageView *)cell.backgroundView).image = rowBackground;
((UIImageView *)cell.selectedBackgroundView).image = selectionBackground;

如果您希望只使用indexPath.row == 0的第一个单元格来使用自定义背景。

这是来自Matt Gallagher的excellent site

Answer 11

你可以这样做：

- (void)viewDidLoad {
    [super viewDidLoad];
    NSIndexPath *ip=[NSIndexPath indexPathForRow:0 inSection:0];
    [myTableView selectRowAtIndexPath:ip animated:YES scrollPosition:UITableViewScrollPositionBottom];
}

在UITableView中选择First Row作为默认值

11 个答案: