使用iOS SDK：
我有一个带UITextFields的UIView，可以启动键盘。我需要它能够：
启动键盘后，允许滚动UIScrollView的内容以查看其他文本字段自动“跳转”（通过向上滚动）或缩短
我知道我需要一个UIScrollView。我已经尝试将UIView的类更改为UIScrollView，但仍然无法上下滚动文本框。
我需要UIView和UIScrollView吗？一个在另一个里面吗？
要自动滚动到活动文本字段，需要执行哪些操作？
理想情况下，尽可能多的组件设置将在Interface Builder中完成。我只想编写需要的代码。
注意：我使用的UIView（或UIScrollView）是由一个选项卡（UITabBar）启动的，它需要正常工作。
我正在添加滚动条，只为键盘出现时使用。尽管不需要它，但我觉得它提供了一个更好的界面，例如，用户可以滚动和更改文本框。
当键盘上下移动时，我可以改变UIScrollView的框架大小。我只是在使用：
-(void)textFieldDidBeginEditing:(UITextField *)textField {
//Keyboard becomes visible
scrollView.frame = CGRectMake(scrollView.frame.origin.x,
scrollView.frame.origin.y,
scrollView.frame.size.width,
scrollView.frame.size.height - 215 + 50); // Resize
}
-(void)textFieldDidEndEditing:(UITextField *)textField {
// Keyboard will hide
scrollView.frame = CGRectMake(scrollView.frame.origin.x,
scrollView.frame.origin.y,
scrollView.frame.size.width,
scrollView.frame.size.height + 215 - 50); // Resize
}
然而，这不会自动“向上移动”或将可见区域中的下部文本字段居中，这是我真正想要的。
这里是我创建的UITextfield（和其他类似的字段）类别，它将使文本字段避开键盘，您应该能够将其按原样放置在视图控制器中，它应该可以工作。它将整个屏幕向上移动，使当前文本字段位于带有动画的键盘上方
#import "UIView+avoidKeyboard.h"
#import "AppDelegate.h"
@implementation UIView (avoidKeyboard)
- (void) becomeFirstResponder {
if(self.isFirstResponder)
return;
[super becomeFirstResponder];
if ([self isKindOfClass:[UISearchBar class]] ||
[self isKindOfClass:[UITextField class]] ||
[self isKindOfClass:[UITextView class]])
{
AppDelegate *appDelegate = [UIApplication sharedApplication].delegate;
CGRect screenBounds = appDelegate.window.frame;
CGFloat keyboardHeight;
CGFloat keyboardY;
CGFloat viewsLowestY;
CGPoint origin = [self.superview convertPoint:self.frame.origin toView:appDelegate.window]; //get this views origin in terms of the main screens bounds
if(UIInterfaceOrientationIsPortrait([[UIApplication sharedApplication] statusBarOrientation])){ //the window.frame doesnt take its orientation into account so if its sideways we must use the x value of the origin instead of the y
keyboardHeight = 216;
keyboardY = screenBounds.size.height - keyboardHeight; //find the keyboards y coord relative to how much the main window has moved up
viewsLowestY = origin.y + self.frame.size.height; //find the lowest point of this view
}
else {
keyboardHeight = 162;
keyboardY = screenBounds.size.width - keyboardHeight;
viewsLowestY = origin.x + self.frame.size.height;
}
CGFloat difference = viewsLowestY - keyboardY + 20; //find if this view overlaps with the keyboard with some padding
if (difference > 0){ //move screen up if there is an overlap
[UIView animateWithDuration:0.3 delay:0.0 options:UIViewAnimationOptionBeginFromCurrentState animations:^{
CGRect frame = appDelegate.window.frame;
if(UIInterfaceOrientationIsPortrait([[UIApplication sharedApplication] statusBarOrientation])){
frame.origin.y -= difference;
}
else {
frame.origin.x -= difference;
}
appDelegate.window.frame = frame;
}
completion:nil];
}
}
}
//look at appDelegate to see when the keyboard is hidden
@end
在appDelegate中添加此函数
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardHides:) name:UIKeyboardWillHideNotification object:nil]; //add in didFinishLaunchingWithOptions
...
- (void)keyboardHides:(NSNotification *)notification
{
[UIView animateWithDuration:0.3 animations:^{
[window setFrame: CGRectMake(0, 0, window.frame.size.width, window.frame.size.height)];
} completion:nil];
}
在textFieldDidBginEditing和textFieldDidEndEditing中调用函数[self-animateTextField:textField up:YES]，如下所示：
-(void)textFieldDidBeginEditing:(UITextField *)textField
{
[self animateTextField:textField up:YES];
}
- (void)textFieldDidEndEditing:(UITextField *)textField
{
[self animateTextField:textField up:NO];
}
-(void)animateTextField:(UITextField*)textField up:(BOOL)up
{
const int movementDistance = -130; // tweak as needed
const float movementDuration = 0.3f; // tweak as needed
int movement = (up ? movementDistance : -movementDistance);
[UIView beginAnimations: @"animateTextField" context: nil];
[UIView setAnimationBeginsFromCurrentState: YES];
[UIView setAnimationDuration: movementDuration];
self.view.frame = CGRectOffset(self.view.frame, 0, movement);
[UIView commitAnimations];
}
我希望这段代码对你有所帮助。
雨燕5
func animateTextField(textField: UITextField, up: Bool) {
let movementDistance: CGFloat = -130
let movementDuration: Double = 0.3
var movement:CGFloat = 0
if up {
movement = movementDistance
} else {
movement = -movementDistance
}
UIView.animate(withDuration: movementDuration, delay: 0, options: [.beginFromCurrentState]) {
self.view.frame = self.view.frame.offsetBy(dx: 0, dy: movement)
}
}
func textFieldDidBeginEditing(_ textField: UITextField) {
animateTextField(textField: textField, up: true)
}
func textFieldDidEndEditing(_ textField: UITextField) {
animateTextField(textField: textField, up: false)
}
