UITableView reloadRowsAtIndexPaths graphical glitch

问题

If I call reloadRowsAtIndexPaths for the first cell of a section, with previous section empty and the one above not-empty, I get a strange animation glitch (even if I specify "UITableViewRowAnimationNone") where the reloaded cell slides down from the above section..

I tried to simplify the example as much as possible:

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 3;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
if (section == 0)
    return 1;
else if (section == 1)
    return 0;
else if (section == 2)
    return 3;
return 0;
}

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

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}

// Configure the cell...
cell.textLabel.text =  @"Text";

return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
NSArray *editedCell = [[NSArray alloc] initWithObjects:indexPath, nil];
//[self.tableView beginUpdates];
[self.tableView reloadRowsAtIndexPaths:editedCell withRowAnimation:UITableViewRowAnimationNone];
//[self.tableView endUpdates];
}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
return @"Section";
}

Actually you can comment out the last method, but it gives a better understanding of the problem.

回答1:

You can set values you want to the cell directly, not letting table to reload itself (and thus avoiding any unwanted animations). Also to make code clearer and avoid code duplication lets move cell setup to a separate method (so we'll be able to call it from different locations):

- (void) setupCell:(UITableViewCell*)cell forIndexPath:(NSIndexPath*)indexPath {
   cell.textLabel.text =  @"Text"; // Or any value depending on index path
}

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

   UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
   [self setupCell:cell forIndexPath:indexPath];
}

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

   // Configure the cell...
   [self setupCell:cell forIndexPath:indexPath];

   return cell;
}

来源：https://stackoverflow.com/questions/7345802/uitableview-reloadrowsatindexpaths-graphical-glitch

标签

ios

uitableview

animation

visual-glitch