SVProgressHUD with query findObjectsInBackgroundWithBlock?

Question

我想用解析查询findObjectsInBackgroundWithBlock生成一个SVProgressHUD。当我测试时，hud在视图出现1秒后离开。

如何使hud保持到查询结束（我知道这是后台查询…）：/

我做错了什么？

知道吗？

这是我的代码：

-(void) viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    [SVProgressHUD showWithMaskType:SVProgressHUDMaskTypeGradient];
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        // time-consuming task
        [self loadShop];
            dispatch_async(dispatch_get_main_queue(), ^{
                [SVProgressHUD dismiss];
            });
    });
}

和方法：

-(void)loadShop {
    //    Configure Shop with Parse DB
    PFQuery *presentationText = [PFQuery queryWithClassName:@"presentationText"];
    [presentationText findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (!error) {
            self.presentationText.text = [[objects valueForKey:@"Text" ] objectAtIndex:0];
        }}];
    PFQuery *categoryQuery = [PFQuery queryWithClassName:@"Category"];
    [categoryQuery findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (!error) {
            self.categoryLabel.text = [[objects valueForKey:@"Text" ] objectAtIndex:0];
            self.categoryLabel2.text = [[objects valueForKey:@"Text" ] objectAtIndex:1];
        }}];
    PFQuery *descriptionLabel = [PFQuery queryWithClassName:@"descriptionLabel"];
    [descriptionLabel findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (!error) {
            self.descriptionLabel.text = [[objects valueForKey:@"Text" ] objectAtIndex:3];
            self.descriptionLabel2.text = [[objects valueForKey:@"Text" ] objectAtIndex:0];
            self.descriptionLabel3.text = [[objects valueForKey:@"Text" ] objectAtIndex:1];
            self.descriptionLabel4.text = [[objects valueForKey:@"Text" ] objectAtIndex:2];
        }}];
    PFQuery *priceLabel = [PFQuery queryWithClassName:@"priceLabel"];
    [priceLabel findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (!error) {
            self.priceLabel.text = [[objects valueForKey:@"Text" ] objectAtIndex:0];
            self.priceLabel2.text = [[objects valueForKey:@"Text" ] objectAtIndex:1];
            self.priceLabel3.text = [[objects valueForKey:@"Text" ] objectAtIndex:2];
            self.priceLabel4.text = [[objects valueForKey:@"Text" ] objectAtIndex:3];
        }}];

    PFQuery *urlImage = [PFQuery queryWithClassName:@"urlImage"];
    [urlImage findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (!error) {
            self.imageButtonURL = [[objects valueForKey:@"URL" ] objectAtIndex:0];
            self.imageButtonURL2 = [[objects valueForKey:@"URL" ] objectAtIndex:1];
            self.imageButtonURL3 = [[objects valueForKey:@"URL" ] objectAtIndex:2];
            self.imageButtonURL4 = [[objects valueForKey:@"URL" ] objectAtIndex:3];
            imageButtonData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:self.imageButtonURL]];
            self.imageButton.imageView.image = [UIImage imageWithData: imageButtonData];
            imageButtonData2 = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:self.imageButtonURL2]];
            self.imageButton2.imageView.image = [UIImage imageWithData: imageButtonData2];
            imageButtonData3 = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:self.imageButtonURL3]];
            self.imageButton3.imageView.image = [UIImage imageWithData: imageButtonData3];
            imageButtonData4 = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:self.imageButtonURL4]];
            self.imageButton4.imageView.image = [UIImage imageWithData: imageButtonData4];
        }}];
}

Answer 1

您使用的是来自解析的块。在提取对象之前启动SVProgressHUD。等它结束了再停下来。

示例：

 PFQuery *priceLabel = [PFQuery queryWithClassName:@"priceLabel"];
//SVProgressHUD starts
    [priceLabel findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (!error) {
            self.priceLabel.text = [[objects valueForKey:@"Text" ] objectAtIndex:0];
            self.priceLabel2.text = [[objects valueForKey:@"Text" ] objectAtIndex:1];
            self.priceLabel3.text = [[objects valueForKey:@"Text" ] objectAtIndex:2];
            self.priceLabel4.text = [[objects valueForKey:@"Text" ] objectAtIndex:3];
//SVProgressHUD stops
        }}];

所以您可以在视图出现时启动它，并在最后一次请求完成后停止它。