经过大量的试验和错误,我放弃了,并提出了这个问题。我见过很多人有类似的问题,但不能得到所有的答案工作正确。
我有一个由自定义单元格组成的UITableView。单元格由相邻的5个文本字段组成(有点像网格)。
当我试图滚动和编辑UITableView底部的单元格时,我不能设法让我的单元格正确地定位在键盘上方。
我看到过很多关于改变视图大小的回答……但到目前为止,没有一种效果很好。
谁能用一个具体的代码示例来阐明这样做的“正确”方式?
经过大量的试验和错误,我放弃了,并提出了这个问题。我见过很多人有类似的问题,但不能得到所有的答案工作正确。
我有一个由自定义单元格组成的UITableView。单元格由相邻的5个文本字段组成(有点像网格)。
当我试图滚动和编辑UITableView底部的单元格时,我不能设法让我的单元格正确地定位在键盘上方。
我看到过很多关于改变视图大小的回答……但到目前为止,没有一种效果很好。
谁能用一个具体的代码示例来阐明这样做的“正确”方式?
当前回答
// scroll tableview so content ends at the middle of the tableview (out of the way of the keyboard)
CGPoint newContentOffset = CGPointMake(0, [self.tableView contentSize].height - (self.tableView.bounds.size.height / 2));
[self.tableView setContentOffset:newContentOffset animated:YES];
其他回答
我刚刚发现另一个bug时使用UITableViewController。当键盘出现时,它不会自动滚动。我注意到这是因为contentInsetAdjustmentBehavior = .never在UITableView上。
Swift 3-4动画和键盘帧改变的解决方案:
首先,创建Bool类型:
// MARK: - Private Properties
private var isKeyboardShowing = false
其次,在系统键盘通知中添加观察者:
// MARK: - Overriding ViewController Life Cycle Methods
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: .UIKeyboardWillHide, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChangeFrame), name: .UIKeyboardWillChangeFrame, object: nil)
}
第三,准备动画功能:
func adjustTableViewInsets(keyboardHeight: CGFloat, duration: NSNumber, curve: NSNumber){
var extraHeight: CGFloat = 0
if keyboardHeight > 0 {
extraHeight = 20
isKeyboardShowing = true
} else {
isKeyboardShowing = false
}
let contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardHeight + extraHeight, right: 0)
func animateFunc() {
//refresh constraints
//self.view.layoutSubviews()
tableView.contentInset = contentInset
}
UIView.animate(withDuration: TimeInterval(duration), delay: 0, options: [UIViewAnimationOptions(rawValue: UInt(curve))], animations: animateFunc, completion: nil)
}
然后添加target/action方法(由观察者调用):
// MARK: - Target/Selector Actions
func keyboardWillShow(notification: NSNotification) {
if !isKeyboardShowing {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
let keyboardHeight = keyboardSize.height
let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber
adjustTableViewInsets(keyboardHeight: keyboardHeight, duration: duration, curve: curve)
}
}
}
func keyboardWillHide(notification: NSNotification) {
let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber
adjustTableViewInsets(keyboardHeight: 0, duration: duration, curve: curve)
}
func keyboardWillChangeFrame(notification: NSNotification) {
if isKeyboardShowing {
let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber
if let newKeyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
let keyboardHeight = newKeyboardSize.height
adjustTableViewInsets(keyboardHeight: keyboardHeight, duration: duration, curve: curve)
}
}
}
最后,不要忘记在deinit或viewWillDisappear中删除观察者:
deinit {
NotificationCenter.default.removeObserver(self)
}
我正在用这些,它们就像魔法一样管用:
bskey控制板- bskey控制板github
tpkeyboardavoidance - tpkeyboardavoidance github
如果你能使用UITableViewController,你就能免费得到这个功能。然而,有时这不是一个选项,特别是当你需要多个视图而不仅仅是UITableView时。
这里介绍的一些解决方案在iOS≥4上不起作用,一些在iPad或横屏模式下不起作用,一些不适用于蓝牙键盘(我们不希望有任何滚动),一些在多个文本字段之间切换时不起作用。因此,如果您选择任何解决方案,请确保测试这些情况。这是我们在InAppSettingsKit中使用的解决方案:
- (void)_keyboardWillShow:(NSNotification*)notification {
if (self.navigationController.topViewController == self) {
NSDictionary* userInfo = [notification userInfo];
// we don't use SDK constants here to be universally compatible with all SDKs ≥ 3.0
NSValue* keyboardFrameValue = [userInfo objectForKey:@"UIKeyboardBoundsUserInfoKey"];
if (!keyboardFrameValue) {
keyboardFrameValue = [userInfo objectForKey:@"UIKeyboardFrameEndUserInfoKey"];
}
// Reduce the tableView height by the part of the keyboard that actually covers the tableView
CGRect windowRect = [[UIApplication sharedApplication] keyWindow].bounds;
if (UIInterfaceOrientationLandscapeLeft == self.interfaceOrientation ||UIInterfaceOrientationLandscapeRight == self.interfaceOrientation ) {
windowRect = IASKCGRectSwap(windowRect);
}
CGRect viewRectAbsolute = [_tableView convertRect:_tableView.bounds toView:[[UIApplication sharedApplication] keyWindow]];
if (UIInterfaceOrientationLandscapeLeft == self.interfaceOrientation ||UIInterfaceOrientationLandscapeRight == self.interfaceOrientation ) {
viewRectAbsolute = IASKCGRectSwap(viewRectAbsolute);
}
CGRect frame = _tableView.frame;
frame.size.height -= [keyboardFrameValue CGRectValue].size.height - CGRectGetMaxY(windowRect) + CGRectGetMaxY(viewRectAbsolute);
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
[UIView setAnimationCurve:[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
_tableView.frame = frame;
[UIView commitAnimations];
UITableViewCell *textFieldCell = (id)((UITextField *)self.currentFirstResponder).superview.superview;
NSIndexPath *textFieldIndexPath = [_tableView indexPathForCell:textFieldCell];
// iOS 3 sends hide and show notifications right after each other
// when switching between textFields, so cancel -scrollToOldPosition requests
[NSObject cancelPreviousPerformRequestsWithTarget:self];
[_tableView scrollToRowAtIndexPath:textFieldIndexPath atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
}
}
- (void) scrollToOldPosition {
[_tableView scrollToRowAtIndexPath:_topmostRowBeforeKeyboardWasShown atScrollPosition:UITableViewScrollPositionTop animated:YES];
}
- (void)_keyboardWillHide:(NSNotification*)notification {
if (self.navigationController.topViewController == self) {
NSDictionary* userInfo = [notification userInfo];
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
[UIView setAnimationCurve:[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
_tableView.frame = self.view.bounds;
[UIView commitAnimations];
[self performSelector:@selector(scrollToOldPosition) withObject:nil afterDelay:0.1];
}
}
以下是InAppSettingsKit中该类的完整代码。要测试它,请使用“Complete List”子窗格,您可以在其中测试上面提到的场景。
如果你使用uitableview来放置你的文本字段(来自Jeff Lamarche),你可以像这样使用委托方法滚动tableview。
(注意:我的文本字段存储在一个数组中,索引与表视图中的行相同)
- (void) textFieldDidBeginEditing:(UITextField *)textField
{
int index;
for(UITextField *aField in textFields){
if (textField == aField){
index = [textFields indexOfObject:aField]-1;
}
}
if(index >= 0)
[self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:index inSection:0] atScrollPosition:UITableViewScrollPositionTop animated:YES];
[super textFieldDidBeginEditing:textField];
}