Question

我有大约80件物品。如果我选择的索引是15（或更小的值），它会滚动到正确的位置。但如果选择指数为70，则不会滚动。但它在我手动滚动时选择了该行。有谁知道如何解决这个问题？

-(void)select:(NSString*)selectedIndex {
    if(selectedIndex == nil){
        return;
    }
    UITableView *tableView = (UITableView*)view;
    if(tableView == nil) {
        return;
    }

    NSIndexPath *nextIndexPath = [self findIndexPath:selectedIndex table:tableView];

    if(nextIndexPath != nil && ![viewController isSelectable:[selectedIndex intValue]]){
        NSArray *indexPaths = [tableView indexPathsForVisibleRows];
        nextIndexPath = [self nextMoveUp:nextIndexPath :indexPaths];
    }
    if(nextIndexPath != nil) {
        [tableView selectRowAtIndexPath:nextIndexPath animated:YES scrollPosition:UITableViewScrollPositionMiddle];
        if ([tableView cellForRowAtIndexPath:nextIndexPath] == nil) {
            // cell is not visible - scroll it into view
            [tableView scrollToRowAtIndexPath:nextIndexPath atScrollPosition:UITableViewScrollPositionNone animated:YES];
        }
    }
}

-(NSIndexPath*)findIndexPath:(NSString*)selectedIndex table:(UITableView*)tableView{
    NSArray *indexPaths = [tableView indexPathsForVisibleRows];
    if(indexPaths == nil || [indexPaths count] == 0) {
        return nil;
    }
    NSIndexPath *lastIndexPath = NULL;
    for (NSIndexPath *path in indexPaths) {
        if(path.row == [selectedIndex intValue]){
            return path;
        }
        lastIndexPath = path;
    }
    if(lastIndexPath != nil && lastIndexPath.row < [selectedIndex intValue]){
        [tableView scrollToRowAtIndexPath:lastIndexPath atScrollPosition:UITableViewScrollPositionTop animated:NO];
        return [self findIndexPath:selectedIndex table:tableView];
    }
    return nil;
}

Answer 1

我刚遇到这个问题。在我的情况下，我在定义所有行之前调用scrollToRowAtIndexPath（或selectRowAtIndexPath），即在所有行上调用cellForRowAtIndexPath之前。我的解决方案是定义一个方法来选择行并使用performSelectorOnMainThread调用它来延迟直到第一次刷新完成。

selectRowAtIndexPath不会滚动到UITableView中的正确位置

1 个答案: