我是iOS开发的新手.
我想知道在iOS 7中是否在UINavigationBar下发送消息时,其标题为：发送,有一个进度条正在加载,直到消息成功发送.
我的问题是：
>那个酒吧是进度条吗？
>在iOS 6中,进度条位于UINavigationBar中？
有人可以给我一些关于如何在iOS 7和iOS6上创建它的想法吗？
我还没有尝试过任何东西.我想阅读一些有关此类问题的教程或示例.
这是我的代码：
int progress = 50;
CGRect navframe = [[self.navigationController navigationBar] frame];
int height= navframe.size.height;
sendView = [[UIView alloc] init];
sendView.frame = CGRectMake(0,200,30);
sendView.backgroundColor = [UIColor clearColor];
UILabel* lbl = [[UILabel alloc] init];
lbl.frame = CGRectMake(0,15);
lbl.backgroundColor = [UIColor clearColor];
lbl.textColor = [UIColor whiteColor];
lbl.shadowColor = [UIColor colorWithWhite:0 alpha:0.3];
lbl.shadowOffset = CGSizeMake(0,-1);
lbl.font = [UIFont boldSystemFontOfSize:12];
lbl.text = @"";
lbl.textAlignment = UITextAlignmentCenter;
[sendView addSubview:lbl];
UIProgressView* pv = [[UIProgressView alloc] initWithProgressViewStyle:UIProgressViewStyleBar];
pv.frame = CGRectMake(0,30-pv.frame.size.height,pv.frame.size.height);
pv.progress = progress/100.0;
[sendView addSubview:pv];
[self.navigationController.navigationBar addSubview:sendView];
不幸的是,进度条不在navigationController下.为什么？
解决方法
我在iOS应用程序中所做的是创建并添加UIProgressBar作为导航栏的子视图,告诉它[progressBar setTranslatesAutoresizingMaskIntoConstraints：NO],并添加约束以将其左右固定到条形图,其底部为导航栏的底部.导航控制器为其维护一个ivar,并提供显示/隐藏它的公共方法,并设置其值.看起来就像Safari中的内容下载一样.
// in UINavigationController subclass
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
UIProgressView *progress = [[UIProgressView alloc] initWithProgressViewStyle:UIProgressViewStyleBar];
progress.tag = DISPLAY_PROGRESS_VIEW;
[self.view addSubview:progress];
UINavigationBar *navBar = [self navigationBar];
NSLayoutConstraint *constraint;
constraint = [NSLayoutConstraint constraintWithItem:progress attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:navBar attribute:NSLayoutAttributeBottom multiplier:1 constant:-0.5];
[self.view addConstraint:constraint];
constraint = [NSLayoutConstraint constraintWithItem:progress attribute:NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual toItem:navBar attribute:NSLayoutAttributeLeft multiplier:1 constant:0];
[self.view addConstraint:constraint];
constraint = [NSLayoutConstraint constraintWithItem:progress attribute:NSLayoutAttributeRight relatedBy:NSLayoutRelationEqual toItem:navBar attribute:NSLayoutAttributeRight multiplier:1 constant:0];
[self.view addConstraint:constraint];
[progress setTranslatesAutoresizingMaskIntoConstraints:NO];
progress.hidden = YES;
}
