我的UIPickerView动画有点问题。 我确实设置了动画，所以当我点击一个按钮时，UIPickerView会向上滑动，再次点击它会向下滑动。但我在 if 上遇到了问题。我尝试设置一个新设置bool并在每个动画后设置它的值，所以 if 只是检查bool。我不确定我是否做得很好，但也许你从代码中得到了想法。 但不幸的是它没有用......有什么想法吗？
- (void)viewDidLoad
{
[super viewDidLoad];
settings = [NSUserDefaults standardUserDefaults];
[settings setBool:NO forKey:@"pickerShown"];
[settings synchronize];
}
- (IBAction)showPicker:(id)sender {
CGRect rect = countryPicker.frame;
CGPoint origin = CGPointMake(0, 510); // Some off-screen y-offset here.
rect.origin = origin;
countryPicker.frame = rect;
if ([settings boolForKey:@"pickerShown"] == YES) {
// Perform transform to slide it off the screen.
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.5];
countryPicker.transform = CGAffineTransformMakeTranslation(0, -0); // Offset.
[UIView commitAnimations];
[settings setBool:NO forKey:@"pickerShown"];
[settings synchronize];
} else if ([settings boolForKey:@"pickerShown"] == NO) {
// Perform transform to slide it onto the screen.
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.5];
countryPicker.transform = CGAffineTransformMakeTranslation(0, -266); // Offset.
[UIView commitAnimations];
[settings setBool:YES forKey:@"pickerShown"];
[settings synchronize];
}
}
编辑：
刚刚找到解决方案...... 如果有人有兴趣 - 这里是：
h。文件：
.
.
.
{
BOOL pickerShown;
}
.
.
.
.m文件：
- (void)viewDidLoad
{
[super viewDidLoad];
CGRect rect = countryPicker.frame;
CGPoint origin = CGPointMake(0, 510); // Some off-screen y-offset here.
rect.origin = origin;
countryPicker.frame = rect;
pickerShown = NO;
}
- (IBAction)showPicker:(id)sender {
if (pickerShown == NO) {
// Perform transform to slide it onto the screen.
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:1];
//[UIView setAnimationDidStopSelector:@selector(hidePicker)];
countryPicker.transform = CGAffineTransformMakeTranslation(0, 0); // Offset.
[UIView commitAnimations];
[self performSelector:@selector(hidePicker) withObject:nil afterDelay:1];
} else if (pickerShown == YES) {
//countryPicker.hidden = NO;
// Perform transform to slide it onto the screen.
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:1];
countryPicker.transform = CGAffineTransformMakeTranslation(0, -266); // Offset.
[UIView commitAnimations];
countryPicker.hidden = NO;
}
}
答案 0 :(得分：4)
如果视图在屏幕上可见，则window属性将为非零。
答案 1 :(得分：1)
刚刚找到解决方案......如果有人感兴趣 - 这里是：
h。文件：
.
.
.
{
BOOL pickerShown;
}
.
.
.
.m文件：
- (void)viewDidLoad
{
[super viewDidLoad];
CGRect rect = countryPicker.frame;
CGPoint origin = CGPointMake(0, 510); // Some off-screen y-offset here.
rect.origin = origin;
countryPicker.frame = rect;
pickerShown = NO;
}
- (IBAction)showPicker:(id)sender {
if (pickerShown == NO) {
// Perform transform to slide it onto the screen.
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:1];
//[UIView setAnimationDidStopSelector:@selector(hidePicker)];
countryPicker.transform = CGAffineTransformMakeTranslation(0, 0); // Offset.
[UIView commitAnimations];
[self performSelector:@selector(hidePicker) withObject:nil afterDelay:1];
} else if (pickerShown == YES) {
//countryPicker.hidden = NO;
// Perform transform to slide it onto the screen.
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:1];
countryPicker.transform = CGAffineTransformMakeTranslation(0, -266); // Offset.
[UIView commitAnimations];
countryPicker.hidden = NO;
}
}
答案 2 :(得分：1)
您可以查看：
self.countryPicker.superview
如果选择器被隐藏，那么superview将为零。否则它将包含视图。
答案 3 :(得分：0)
如果你想要的只是显示选择器视图的基本效果，那么再次删除它会有一种更简单的方法。
伪代码：
//do any picker initialization here
if(!pickerIsShowing)
[self.view addSubview:yourPickerView];
else
[self.yourPickerView removeFromSuperView];