あなたがそれを使うなら、あなたも助けを得ると思います:)
syncProgressBarView = [[UIProgressView alloc]initWithProgressViewStyle:UIProgressViewStyleDefault];
syncProgressBarView.frame =CGRectMake(20, 55, 250, 20);
[syncProgressBarView setProgress:0.0f animated:NO];
syncProgressBarView.backgroundColor =[UIColor clearColor];
[progressView addSubview:syncProgressBarView];
サブビュー用の新しいビューを作成する UIProgressView
progressView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, DeviceWidth, 100)];
[[UIApplication sharedApplication].keyWindow addSubview:progressView];
progressView.backgroundColor = [UIColor clearColor];
progressView.center = [UIApplication sharedApplication].keyWindow.center;
syncProgressBarView.frame = CGRectMake(progressView.frame.size.width/2 - 250/2, progressView.frame.size.height/2 - 10, 250, 20);
[[UIApplication sharedApplication].keyWindow bringSubviewToFront:[progressView superview]];
あなたがしなければならないもう一つのこと...
dispatch_async(dispatch_get_main_queue(), ^{
[self updateProgressBar];
});