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。
答案 0 :(得分:110)
- (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。
答案 1 :(得分:9)
Swit 3.0更新解决方案
let indexPath = IndexPath(row: 0, section: 0)
tblView.selectRow(at: indexPath, animated: true, scrollPosition: .bottom)
答案 2 :(得分:8)
- (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];
}
答案 3 :(得分:5)
- (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];
}
}
答案 4 :(得分:3)
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)
}
答案 5 :(得分:2)
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。
答案 6 :(得分:2)
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:)
答案 7 :(得分:1)
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
答案 8 :(得分:1)
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
}
答案 9 :(得分:0)
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
答案 10 :(得分:-1)
你可以这样做:
- (void)viewDidLoad {
[super viewDidLoad];
NSIndexPath *ip=[NSIndexPath indexPathForRow:0 inSection:0];
[myTableView selectRowAtIndexPath:ip animated:YES scrollPosition:UITableViewScrollPositionBottom];
}