Objective c MBProgressHUD与CustomView：为什么可以'；我不能设置自定义视图的动画吗？

这不知怎的不起作用…为什么？如何在不制作gif动画的情况下实现旋转自定义螺旋桨

-(UIView *)propTest
{
    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 37, 37)];

    UIImageView *movablePropeller = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 37 , 37)];

    movablePropeller.image = [UIImage imageNamed:@"MovablePropeller"];


    [view addSubview:movablePropeller];
    movablePropeller.center = view.center;

    CABasicAnimation *rotation;
    rotation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
    rotation.fromValue = [NSNumber numberWithFloat:0.0f];
    rotation.toValue = [NSNumber numberWithFloat:(2 * M_PI)];
    rotation.cumulative = true;
    rotation.duration = 1.2f; // Speed
    rotation.repeatCount = INFINITY; // Repeat forever. Can be a finite number.

    [movablePropeller.layer addAnimation:rotation forKey:@"Spin"];

    return view;
}

-(void)presentMyHud
{
    MBProgressHUD *hud = [[MBProgressHUD alloc] initWithView:self.view];
    [self.view addSubview:hud];
    hud.mode = MBProgressHUDModeCustomView;
    hud.customView = [self propTest];
    hud.detailsLabelText = @"Getting data";
    [hud show:YES];
}

---

但是我的推进器保持静止…

如果推进器没有旋转，如果您没有立即将此

视图添加到视图层次结构中，则可能会发生这种情况。通常，在
addAnimation
之前，最好先将视图添加到视图层次结构中

- (UIView *)addPropellerToView:(UIView *)view {
    UIView *containerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 37, 37)];

    // make sure to add it to the view hierarchy

    [view addSubview:containerView];

    // if you want to center it, set its `center` to be in the middle of the `bounds` ... don't use `center`

    containerView.center = CGPointMake(view.bounds.origin.x + view.bounds.size.width / 2, view.bounds.origin.y + view.bounds.size.height / 2);

    // I'd just use the `bounds` of the container view; reducing the risk that we get its coordinates wrong

    UIImageView *movablePropeller = [[UIImageView alloc] initWithFrame:containerView.bounds];

    movablePropeller.image = [UIImage imageNamed:@"MovablePropeller"];
    movablePropeller.contentMode = UIViewContentModeScaleAspectFill;

    [containerView addSubview:movablePropeller];

    // never set the center of a view to the center of its super view ... those are two different coordinate systems.
    // in this case, this line isn't needed at all, so I'll remove it.
    //
    //     movablePropeller.center = containerView.center;

    CABasicAnimation *rotation;
    rotation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
    rotation.fromValue = @(0);
    rotation.toValue = @(2 * M_PI);
    rotation.cumulative = true;
    rotation.duration = 1.2f;
    rotation.repeatCount = INFINITY;

    [movablePropeller.layer addAnimation:rotation forKey:@"Spin"];

    return containerView;
}

屈服：



一些不相关的观察结果：


 >P>如果您想在视图B中集中查看A，请将视图A的<代码>中心>代码>坐标到B的“代码>界线< /代码>的中点，而不是B的<代码>中心< /代码>。例如，你永远不想做：

A.center = B.center;

你想要的是：

A.center = CGPointMake(B.bounds.origin.x + B.bounds.size.width / 2, B.bounds.origin.y + B.bounds.size.height / 2);

我知道看起来应该是一样的，但事实并非如此。A的
中心
是在B的坐标系中定义的，就像
框架
一样。但B的
中心
是在其superview的坐标系中定义的，这可能是完全不同的。有时你不会注意到差异（特别是如果B的
原点是
{0，0}
），但这表明对不同坐标系的误解，如果B不在
{0，0}
，那么一切都会出错

您可以使用
NSNumber
文字，将
[NSNumber numberwhithfloat:0.0f]
替换为
@（0）

您确实不需要那个容器视图，因此可以简化例程，如下所示

- (UIView *)addPropellerTo:(UIView *)view {
    UIImageView *movablePropeller = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 37, 37)];
    movablePropeller.image = [UIImage imageNamed:@"MovablePropeller"];
    movablePropeller.contentMode = UIViewContentModeScaleAspectFill;
    [view addSubview:movablePropeller];
    movablePropeller.center = CGPointMake(view.bounds.origin.x + view.bounds.size.width / 2, view.bounds.origin.y + view.bounds.size.height / 2);

    CABasicAnimation *rotation;
    rotation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
    rotation.fromValue = @(0);
    rotation.toValue = @(2 * M_PI);
    rotation.cumulative = true;
    rotation.duration = 1.2f;
    rotation.repeatCount = INFINITY;

    [movablePropeller.layer addAnimation:rotation forKey:@"Spin"];

    return movablePropeller;
}