如何在加载UITableViewCell时设置UIActivityIndi catorView

问题描述 投票:35回答:5

我有两个UITableViewControllers,A和B.当我点击表A中的一个单元格时,我将使用UINavigationController来推送表格视图控制器B.但是B的数据是从Internet下载的,这需要几秒钟。所以我想在加载B时添加一个UIActivityIndicatorView。我怎样才能做到这一点?

iphone objective-c ios xcode uiactivityindicatorview
5个回答
51
投票

您可以将UIActivityIndi​​catorView添加为单元格的accessoryView。

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

    UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    spinner.frame = CGRectMake(0, 0, 24, 24);
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    cell.accessoryView = spinner;
    [spinner startAnimating];
    [spinner release];
}

30
投票

在tableview B类的viewDidLoad中,添加一个活动指示符。

// Create the Activity Indicator.
    let activityIndicator = UIActivityIndicatorView(activityIndicatorStyle: .gray)
    activityIndicator.hidesWhenStopped = true
    view.addSubview(activityIndicator)

    // Position it at the center of the ViewController.
    activityIndicator.translatesAutoresizingMaskIntoConstraints = false
    NSLayoutConstraint.activate([
        activityIndicator.centerXAnchor.constraint(equalTo: view.centerXAnchor),
        activityIndicator.centerYAnchor.constraint(equalTo: view.centerYAnchor)])
    activityIndicator.startAnimating()

现在调用从网络下载数据的方法。

myDownloadMethod()

如果您不希望UI在此过程中无响应,请在不同的主题中执行此操作。

为此阅读此主题。 Can I use a background thread to parse data?

当您收到下载内容的通知时,请停止指示。

activityIndicator.stopAnimating()

现在,您可以调用tableview.reloadData()重新加载表以显示新内容。


8
投票
UIActivityIndicatorView * activityindicator1 = [[UIActivityIndicatorView alloc]initWithFrame:CGRectMake(150, 200, 30, 30)];
[activityindicator1 setActivityIndicatorViewStyle:UIActivityIndicatorViewStyleWhiteLarge];
[activityindicator1 setColor:[UIColor orangeColor]];
[self.view addSubview:activityindicator1];
[activityindicator1 startAnimating];

[self performSelector:@selector(callfunction) withObject:activityindicator1 afterDelay:1.0];

-(void)callfunction
{
// Here your stuf
}

4
投票

它对我很有用,你可以尝试一下: [activityIndi​​cator startAnimating]当didHighlightRowAtIndexPath,[activityIndi​​cator stopAnimating]时didUnhighlightRowAtIndexPath比didSelectRowAtIndexPath有用。

- (void)runIndicatorAtIndexPath:(NSIndexPath *)indexPath display:(BOOL)playing{ 
    UIActivityIndicatorView *activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
    cell.accessoryView = activityIndicator;
    playing == YES ?[activityIndicator startAnimating]:[activityIndicator stopAnimating];
}
- (void)tableView:(UITableView *)tableView didHighlightRowAtIndexPath:(NSIndexPath *)indexPath {
    [self runIndicatorAtIndexPath:indexPath display:YES];
}
- (void)tableView:(UITableView *)tableView didUnhighlightRowAtIndexPath:(NSIndexPath *)indexPath{
    [self runIndicatorAtIndexPath:indexPath display:NO];
}

3
投票

如果服务器上有更多数据,下面的代码将在表视图的页脚显示一个微调器。您可以根据从服务器获取数据的逻辑来更改它。

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    /* set cell attributes here */
    NSInteger lastSectionIndex = [tableView numberOfSections] - 1;
    NSInteger lastRowIndex = [tableView numberOfRowsInSection:lastSectionIndex] - 1;
    if ((indexPath.section == lastSectionIndex) && (indexPath.row == lastRowIndex)) {
           if(isMoreDataAvailableOnserver)
           {
            [self showSpinnerAtFooter];
            [self getMoreDataFromServer];
           }
           else
           {
            [self hideSpinnerAtFooter];
           }
    }
    return cell;
}
-(void) hideSpinnerAtFooter {
    self.tableView.tableFooterView =nil;
}
-(void) showSpinnerAtFooter {
    UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    [spinner startAnimating];
    spinner.frame = CGRectMake(0, 0, 320, 44);
    self.tableView.tableFooterView = spinner;
}
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