【发布时间】：2013-02-07 06:15:44
【问题描述】：
我有一个名为“刷新数据”的 UIBarButtonItem。当用户单击它时，应用程序应刷新其数据。单击该按钮时发生的情况是启动 Web 服务并带来 xml 数据，它们的顺序为 30000-40000 条记录。所以为了防止 UI 挂起，我写了一个后台线程并在那里加载。
- (void)refreshDataAction
{
NSLog(@"Refresh Data");
//Put up an alert box indicating user to wait while data is loading.
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Data is Loading"
message:@"Please wait while data is being refreshed."
delegate:self
cancelButtonTitle:@"OK"
otherButtonTitles:nil, nil];
alert.tag = 10;
[alert show];
}
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
NSLog(@"hit in clickedbuttonatindex alertview at 259");
self.refreshActIndicator.hidden = NO;
[self.refreshActIndicator startAnimating];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,
(unsigned long)NULL), ^(void) {
[self getAllCustomerValues];
NSError *nwerror = nil;
if (![self.secondMOC save:&nwerror])
{
NSLog(@"209 Failed to save second MOC");
}
else
{
//NSLog(@"saved success");
}
});
}
就像您可以看到警报视图一样。我单击“确定”，该框仍然“变黑”并挂在屏幕上。然后 7-8 秒后，该框消失，活动指示器开始动画。我的目标是得到这样的东西。 1.用户点击刷新数据按钮。 2.警报视图出现。 3.用户点击确定。 4.警报框消失，后台线程立即开始工作，我看到活动指示器工作/动画。
当活动指示器动画时，用户会知道要等待。那么我如何让应用程序在用户单击“确定”后立即开始动画并且警报视图确定不会变黑。我清楚了吗？如果您需要更多信息，请询问。谢谢
编辑：该屏幕在当天第一次加载时有一个后台线程在运行。在此之前有一个屏幕。在它上面我有继续按钮并点击它启动后台线程，它与这里的这个完全一样。我不会杀死它或任何东西。
编辑 2：
- (void)refreshDataAction
{
NSLog(@"Refresh Data");
self.txtCustomerSearch.text =@"";
[self cleanUPPreviousLabels];
//Put up an alert box indicating user to wait while data is loading.
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Data is Loading"
message:@"Please wait while data is being refreshed."
delegate:self
cancelButtonTitle:@"OK"
otherButtonTitles:nil, nil];
//alert.tag = 10;
//[alert show];
[alert performSelectorOnMainThread:@selector(show) withObject:nil waitUntilDone:FALSE];
NSLog(@"hit in willpresenet alertview at 221");
self.refreshActIndicator.hidden = NO;
[self.refreshActIndicator startAnimating];
NSLog(@"Dispatching");
//Disable the view and all the other controls
self.txtCustomerSearch.userInteractionEnabled =NO;
self.txtCustomerSearch.enabled =NO;
self.btnSearch.enabled =NO;
self.btnSearch.userInteractionEnabled = NO;
self.scrollView.userInteractionEnabled = NO;
//self.view.userInteractionEnabled =NO;
self.chkButton.enabled = NO;
[self deletePreviousValues];
dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{
NSLog(@"Getting customer values");
[self getAllCustomerValues];
NSLog(@"Got customer values");
NSError *nwerror = nil;
if (![self.secondMOC save:&nwerror])
{
NSLog(@"209 Failed to save second MOC");
}
else
{
//NSLog(@"saved success");
}
self.txtCustomerSearch.userInteractionEnabled = YES;
self.txtCustomerSearch.enabled =YES;
self.btnSearch.enabled =YES;
self.btnSearch.userInteractionEnabled = YES;
self.scrollView.userInteractionEnabled = YES;
self.view.userInteractionEnabled =YES;
self.chkButton.enabled = YES;
[self.refreshActIndicator stopAnimating];
NSLog(@"Saved");
});
NSLog(@"Dispatched");
}
【问题讨论】：
-
getAllCustomerValues 方法是否同步？
-
@GeorgeSachin。我怎么知道呢？
-
@GeorgeSachin - 因为它是在异步队列上执行的，所以它将异步运行。
标签： ios animation uialertview uiactivityindicatorview