用動畫滑動UIView

Question

點擊按鈕後，我想要一個UIView向下滑動約50%的屏幕。幻燈片應該是動畫的。以下是我迄今爲止嘗試：

- (IBAction)moveDownButtonClicked:(id)sender { 

    _sliderView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, [[UIScreen mainScreen] bounds].size.width 
                  , [[UIScreen mainScreen] bounds].size.height*0.5)]; 
    [UIView beginAnimations:nil context:NULL]; 
    [UIView setAnimationDuration:1.0]; 
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut]; 
    _sliderView.frame = CGRectMake(0,0,320,20); 
    [UIView commitAnimations]; 
} 

Answer 1

首先，你必須插入_sliderView視圖層次結構：

[self.view addSubview: _sliderView]; 

或

[self.view.window addSubview: _sliderView]; 

然後進行變換。

也許這你想要什麼：

- (IBAction)moveDownButtonClicked:(id)sender { 

    _sliderView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, [[UIScreen mainScreen] bounds].size.width 
                  , 0)]; 

    [self.view.window addSubview: _sliderView]; 

    [UIView beginAnimations:nil context:NULL]; 
    [UIView setAnimationDuration:1.0]; 
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut]; 
    _sliderView.frame = CGRectMake(0,0, 
            [[UIScreen mainScreen] bounds].size.width, 
            [[UIScreen mainScreen] bounds].size.height*0.5); 
    [UIView commitAnimations]; 
}