我建议不要修改 中.accessoryType
的所有单元格,而是将选定的索引存储在某个 ivar 中,并更改数据源方法中的 ,即didSelectRowAtIndexPath:
.accessoryType
-tableView:cellForRowAtIndexPath:
-(void)tableView:(UITableView*)tableView didSelectRowAtIndexPath:(NSIndexPath*)indexPath {
self.selectedIndexPath = indexPath;
[tableView reloadData];
}
-(UITableViewCell*)tableView:(UITableView*)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath {
...
cell.accessoryType = [indexPath compare:self.selectedIndexPath] == NSOrderedSame
? UITableViewCellAccessoryCheckmark
: UITableViewCellAccessoryNone;
...
}
这样,只有可见的单元格会受到影响,屏幕外的数百万个其他单元格将不需要修改。
非常正确,这是在选择单元格的一般情况下在 Swift 中的完整实现。您可以在类中的其他地方使用 selectedIndexPath ,只要您认为合适。例如,在cellForRowAtIndexPath
选择合适的细胞原型。
// SelectingTableViewController
import UIKit
class SelectingTableViewController: UITableViewController
{
internal var selectedIndexPath:NSIndexPath? = nil
override func viewDidLoad()
{
super.viewDidLoad()
tableView.estimatedRowHeight = 68.0
tableView.rowHeight = UITableViewAutomaticDimension
self.clearsSelectionOnViewWillAppear = false;
}
override func tableView
(tableView:UITableView, didSelectRowAtIndexPath indexPath:NSIndexPath)
{
print("did select....")
// in fact, was this very row selected,
// and the user is clicking to deselect it...
// if you don't want "click a selected row to deselect"
// then on't include this clause.
if selectedIndexPath == indexPath
{
print("(user clicked on selected to deselect)")
selectedIndexPath = nil
tableView.reloadRowsAtIndexPaths(
[indexPath],
withRowAnimation:UITableViewRowAnimation.None)
tableView.deselectRowAtIndexPath(indexPath, animated:false)
return
}
// in fact, was some other row selected??
// user is changing to this row? if so, also deselect that row
if selectedIndexPath != nil
{
let pleaseRedrawMe = selectedIndexPath!
// (note that it will be drawn un-selected
// since we're chaging the 'selectedIndexPath' global)
selectedIndexPath = indexPath
tableView.reloadRowsAtIndexPaths(
[pleaseRedrawMe, indexPath],
withRowAnimation:UITableViewRowAnimation.None)
return;
}
// no previous selection.
// simply select that new one the user just touched.
// note that you can not use Apple's willDeselectRowAtIndexPath
// functions ... because they are freaky
selectedIndexPath = indexPath
tableView.reloadRowsAtIndexPaths(
[indexPath],
withRowAnimation:UITableViewRowAnimation.None)
}
}