類似iPhone鍵盤出現動畫的實現

用顯示鍵盤動畫的方式來顯示DatePicker

１.顯示DatePicker

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1. - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
2. {
3. UITableViewCell *targetCell = [tableView cellForRowAtIndexPath:indexPath];
4. self.pickerView.date = [self.dateFormatter dateFromString:targetCell.detailTextLabel.text];
6. // 查看DatePicker是否顯示在屏幕上
7. if (self.pickerView.superview == nil)
8. {

1. 　　　　　　　　　　//　添加選取器到屏幕上

1. [self.view.window addSubview: self.pickerView];
3. // size up the picker view to our screen and compute the start/end frame origin for our slide up animation
4. //
5. // 計算DatePicker初始的Frame
6. CGRect screenRect = [[UIScreen mainScreen] applicationFrame];
7. CGSize pickerSize = [self.pickerView sizeThatFits:CGSizeZero];
8. CGRect startRect = CGRectMake(0.0,
9. screenRect.origin.y + screenRect.size.height,
10. pickerSize.width, pickerSize.height);
11. self.pickerView.frame = startRect;
13. // compute the end frame
14. CGRect pickerRect = CGRectMake(0.0,
15. screenRect.origin.y + screenRect.size.height - pickerSize.height,
16. pickerSize.width,
17. pickerSize.height);
18. // start the slide up animation
19. [UIView beginAnimations:nil context:NULL];
20. [UIView setAnimationDuration:0.3];
22. // we need to perform some post operations after the animation is complete
23. [UIView setAnimationDelegate:self];
25. self.pickerView.frame = pickerRect;
27. // shrink the table vertical size to make room for the date picker
28. CGRect newFrame = self.tableView.frame;
29. newFrame.size.height -= self.pickerView.frame.size.height;
30. self.tableView.frame = newFrame;
31. [UIView commitAnimations];
33. // add the "Done" button to the nav bar
34. self.navigationItem.rightBarButtonItem = self.doneButton;
35. }

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1. - (IBAction)doneAction:(id)sender
2. {
3. CGRect screenRect = [[UIScreen mainScreen] applicationFrame];
4. CGRect endFrame = self.pickerView.frame;
5. endFrame.origin.y = screenRect.origin.y + screenRect.size.height;
7. // start the slide down animation
8. [UIView beginAnimations:nil context:NULL];
9. [UIView setAnimationDuration:0.3];
11. // we need to perform some post operations after the animation is complete
12. [UIView setAnimationDelegate:self];
13. [UIView setAnimationDidStopSelector:@selector(slideDownDidStop)];
15. self.pickerView.frame = endFrame;
16. [UIView commitAnimations];
18. // grow the table back again in vertical size to make room for the date picker
19. CGRect newFrame = self.tableView.frame;
20. newFrame.size.height += self.pickerView.frame.size.height;
21. self.tableView.frame = newFrame;
23. // remove the "Done" button in the nav bar
24. self.navigationItem.rightBarButtonItem = nil;
26. // deselect the current table row
27. NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
28. [self.tableView deselectRowAtIndexPath:indexPath animated:YES];
29. }

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1. - (void)slideDownDidStop
2. {
3. // the date picker has finished sliding downwards, so remove it
4. [self.pickerView removeFromSuperview];
5. }