Question

我正在做一个同步的网络请求，我想展示进展，但更重要的是，只要我点击“开始”它就会离开比赛，忽略了打开NetworkActivty微调器或更改标签等内容。

我意识到进度条可能要等到我有时间异步写入提取，但是我可以让程序等到标签发生变化吗？或者至少是伪造它的方法？

在UIButton上的TouchUpInside上我有。。。

-(IBAction)startButtonPressed

{ [UIApplication sharedApplication] .networkActivityIndicatorVisible = YES;

NSString *lastUpdate = [[self getLastUpdateDate] stringByReplacingOccurrencesOfString:@" " withString:@"%20"];
startButton.enabled = NO;
cancelButton.enabled = NO;
resetSwitch.enabled = NO;
cleanSwitch.enabled = NO;
//check the # of customer updates and update accordingly

statusLabel.text = @"Updating Customers. . .";
//[self performSelector:(@selector(updateProgress:withStatus:)) withObject:0.0f withObject:@"Updating Customers. . . " afterDelay:500];
//[self performSelector:(@selector(updateProgressIndicators)) withObject:nil afterDelay:0];

if (clean) {
    [self deleteALL];
}

if ([self customersCount] < 1000 && !reset)
    [self addCustomers:lastUpdate];
else
    [self addCustomers:nil];

//check the # of product updates and update accordingly, reset does not affect products
statusLabel.text = @"Updating Products. . .";

if ([self productsCount] < 25000 || !clean)
    [self addProducts:lastUpdate];
else
    [self addProducts:nil];

//check the # of vendor updates and update accordingly, reset does not affect vendors
statusLabel.text = @"Updating Vendors. . . ";
if ([self vendorsCount] < 1000 || !clean || [[self fetchVendor:@"0002"] count] == 0) {
    [self addVendors:lastUpdate];
}else{
    [self addVendors:nil];
}

statusLabel.text = @"Updating History. . . ";
[self getHistory];



statusLabel.text = @"Updating Custom Pricing. . . ";
if ([self customPricesCount] < 500 && !reset) {
    [self addCustomPrices:lastUpdate];
}else{
    [self addCustomPrices:nil];
}

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"MM-dd-yyyy HH:mm:ss"];
[self setLastUpdateDate:[dateFormatter stringFromDate:[NSDate date]]];  
[dateFormatter release];

statusLabel.text = @"Done!";
cancelButton.enabled = YES;
cancelButton.tag = 1;
cancelButton.titleLabel.text = @"Close";
startButton.enabled = NO;

[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
}

Answer 1

您有一种可能性是在主线程上安排执行网络请求。这将允许UI在发送网络请求之前得到更新。

如果要这样做，您应该用两种方法分割代码：

UI更改（活动指示器等）直到同步网络请求;
同步网络请求和响应处理（使用UI更新）;

假设2.由一个名为offToTheRaces的方法实现，您可以从第一个方法安排此方法：

[self performSelector:@selector(offToTheRaces) withObject:nil afterDelay:0];

请注意，您没有以这种方式进行任何类型的多线程，也没有引入延迟。您只需安排在主循环再次执行后执行的方法，这将为tue UI提供更新的机会。

如何暂停我的应用程序足够长的时间让我的屏幕“赶上”

1 个答案: