How can i add a activity indicator below the UITab

问题:

In my application i want to add activity indicator under UItableview where tableview will scroll but i do not know how can i add activity indicator over there.

To elaborate,when i will finish the scrolling of tableview then for more data i have to set a refresh option by an activity indicator.

i have tried it at the top of the tableview and it worked but i dont know how can i add it below the tableview. here is some sample code..

      - (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
if (isLoading) return;
isDragging = YES;


refreshHeaderView = [[UIView alloc] initWithFrame:CGRectMake(0, scrollView.contentOffset.y + REFRESH_HEADER_HEIGHT, 320, REFRESH_HEADER_HEIGHT)];
refreshHeaderView.backgroundColor = [UIColor clearColor];

refreshLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, scrollView.contentOffset.y + REFRESH_HEADER_HEIGHT, 320, REFRESH_HEADER_HEIGHT)];
refreshLabel.backgroundColor = [UIColor clearColor];
refreshLabel.font = [UIFont boldSystemFontOfSize:12.0];
refreshLabel.textAlignment = UITextAlignmentCenter;

refreshArrow = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"refresharrow.png"]];
refreshArrow.frame = CGRectMake((scrollView.contentOffset.y + REFRESH_HEADER_HEIGHT - 27) / 2,
                                (scrollView.contentOffset.y + REFRESH_HEADER_HEIGHT - 44) / 2,
                                27, 44);

refreshSpinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
refreshSpinner.frame = CGRectMake((scrollView.contentOffset.y + REFRESH_HEADER_HEIGHT - 20) / 2, (scrollView.contentOffset.y + REFRESH_HEADER_HEIGHT - 20) / 2, 20, 20);
refreshSpinner.hidesWhenStopped = YES;

[refreshHeaderView addSubview:refreshLabel];
[refreshHeaderView addSubview:refreshArrow];
[refreshHeaderView addSubview:refreshSpinner];
[tableview addSubview:refreshHeaderView];


}

 - (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (isLoading) {
    // Update the content inset, good for section headers
    if (scrollView.contentOffset.y > 0){
        NSLog(@"scrollView.contentOffset.y 1= %d",scrollView.contentOffset.y );
        tableview.contentInset = UIEdgeInsetsZero;
    }
    else if (scrollView.contentOffset.y >= -REFRESH_HEADER_HEIGHT){
        NSLog(@"scrollView.contentOffset.y 2= %d",scrollView.contentOffset.y );
        tableview.contentInset = UIEdgeInsetsMake(-scrollView.contentOffset.y, 0, 0, 0);
    }
} else if (isDragging && scrollView.contentOffset.y > scrollView.contentOffset.y + REFRESH_HEADER_HEIGHT) {
    // Update the arrow direction and label
    [UIView beginAnimations:nil context:NULL];
    if (scrollView.contentOffset.y > scrollView.contentOffset.y + REFRESH_HEADER_HEIGHT) {
        // User is scrolling above the header
        NSLog(@"scrollView.contentOffset.y 3= %d",scrollView.contentOffset.y );
        refreshLabel.text = self.textRelease;
        [refreshArrow layer].transform = CATransform3DMakeRotation(M_PI, 0, 0, 1);
    } else { // User is scrolling somewhere within the header
        refreshLabel.text = self.textPull;
        [refreshArrow layer].transform = CATransform3DMakeRotation(M_PI * 2, 0, 0, 1);
    }
    [UIView commitAnimations];
}
}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
if (isLoading) return;
isDragging = NO;
if (scrollView.contentOffset.y >= scrollView.contentOffset.y + REFRESH_HEADER_HEIGHT) {
    // Released above the header
    [self startLoading];
}
}

so please someone give me some example code about how can i do that.

actually i am new in iphone application development.So please help me.

Thanks in Advance.

回答1:

The best way to add activity indicator is at footer of tableview.

    - (UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section { 
UIView *headerView = [[[UIView alloc] init]autorelease];

    [headerView setBackgroundColor:[UIColor clearColor]];

UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button addTarget:self 
           action:@selector(aMethod:)
 forControlEvents:UIControlEventTouchDown];
[button setTitle:@"Load More" forState:UIControlStateNormal];
button.frame = CGRectMake(10.0, 210.0, 160.0, 40.0);


    [headerView addSubview:button];

    [headerLabel release];

    return headerView;

}  

Add a button to the footerView and set action to button (as you needed). This how app store tableview works. On clicking button fetch some more data add to table array scroll the table without animation.

回答2:

This is how I've done it:

UIActivityIndicatorView *spinner = [[[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray] autorelease];
[spinner startAnimating];
spinner.frame = CGRectMake(0, 0, 320, 44);
self.tableView.tableFooterView = spinner;

Then you just set tableFooterView to nil to remove it.

Note: 44, btw, is the default height of a UITableViewCell when using UITableViewStylePlain. It's 45 for UITableViewStyleGrouped.

回答3:

Swift Update :-

let pagingSpinner = UIActivityIndicatorView(activityIndicatorStyle: .Gray)
pagingSpinner.startAnimating()
pagingSpinner.color = UIColor(red: 22.0/255.0, green: 106.0/255.0, blue: 176.0/255.0, alpha: 1.0)
pagingSpinner.hidesWhenStopped = true
tableView.tableFooterView = pagingSpinner

回答4:

One more way to add activity indicator. Check if your data displayed is not equals to the total count of data. Then you add one extra cell and Add "View More" button. When i click on the view more the hide that button and add activity indicator in that cell. And when process is done then reload the table view.

Thanks.