SubView slide in animation, iphone

问题

I have a UIview Containing two UIButtons.

-(void)ViewDidLoad
{
    geopointView = [[UIView alloc] initWithFrame:CGRectMake(0, 350, 120, 80)];
    geopointView.backgroundColor = [UIColor greenColor]; 

    UIButton *showGeoPointButton = [[UIButton buttonWithType:UIButtonTypeRoundedRect] retain];
    showGeoPointButton.frame = CGRectMake(0, 0, 120, 40);
    showGeoPointButton.titleLabel.font = [UIFont systemFontOfSize:13.0];
    [showGeoPointButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[showGeoPointButton addTarget:self action:@selector(showPlaces:) forControlEvents:UIControlEventTouchUpInside];

    UIButton *SaveButton = [[UIButton buttonWithType:UIButtonTypeRoundedRect] retain] 
    SaveButton.frame = CGRectMake(0, 40, 120, 40);
    SaveButton.titleLabel.font = [UIFont systemFontOfSize: 15.0];
    [SaveButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    [SaveButton addTarget:self action:@selector(savePlacePopUp) forControlEvents:UIControlEventTouchUpInside];

    [geopointView addSubview:showGeoPointButton];
    [geopointView addSubview:SaveButton];
}

I want to animate slide in of UIview when following method is called.

-(void) showAnimation

I tried to do it by following way but I can see no animation. How can I do it?

-(void) showAnimation{
    [UIView animateWithDuration:10.0 animations:^{
        [self.view addSubview:geopointView];
    }];
}

Thannks for any help in advance.

回答1:

You need to add the subview with a frame value that is where you want the animation to begin from (off-screen?) then change the frame value inside your animation block. The frame will change over the duration, causing the appearance of movement. The view must already be a subview - I don't believe adding a subview is something you can animate, it makes no sense.

-(void)showAnimation {

    [self.view addSubview:geopointView]
    geopointView.frame = // somewhere offscreen, in the direction you want it to appear from
    [UIView animateWithDuration:10.0 
                     animations:^{
                         geopointView.frame = // its final location
                     }];
}

来源：https://stackoverflow.com/questions/7343915/subview-slide-in-animation-iphone