TableViewCell中的更改立即生效

Question

I have a TableView with a custom cell. One of the subviews in the cell is a UIButton. When a user clicks on the button, I want the background to change. I get all of that working. But the problem is I cannot see the change until after I scroll the affected cell off screen and then return it on screen. But I want to see the change immediately, without the onscreen offscreen bit. How might I do that?

For a bit more about my implementation:

Inside the method (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath I have the line

....
[cell.myBtn addTarget:self action:@selector(onMyBtnTapped:) forControlEvents:UIControlEventTouchUpInside];

And then inside the onMyBtnTapped method is where I effect the color change.

So perhaps what I need to do is to redraw a specific cell from the parent view controller (?).

a bit more

I have gotten as far as getting the cell using [self.tableView cellForRowAtIndexPath:indexPath]; . But now that I have the cell, I don't know how to get it to redraw itself. I do this on android all the time. I am not sure how to do it on iOS.

Answer 1

您可以在按钮单击时重新加载UITableViewCell：

[self.tableView reloadRowsAtIndexPaths:@[indexPathOfGivenCell] withRowAnimation:UITableViewRowAnimationNone];

Answer 2

You should be able to place the following in the method.

[self.tableView beginUpdates];
[self.tableView reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationNone];
[self.tableView endUpdates];

Answer 3

You can ask to redraw cell at visible rows:

NSArray *visibleIndexPaths       = [tableView indexPathsForVisibleRows];
[self.tableView reloadRowsAtIndexPaths:visibleIndexPaths withRowAnimation: UITableViewRowAnimationFade];