Xamarin.form 键盘出现时向上移动视图 [英] Xamarin.form Move up view when keyboard appear
问题描述
我正在尝试构建一个聊天应用 UI,布局的想法非常简单:
I'm trying to build a Chat app UI, the idea of the Layout was pretty simple:
当输入栏聚焦时,键盘出现并推"上聊天栏,因为它是一个网格,ListView 将调整大小以适应屏幕:
When the input bar is focused, keyboard show up and "push" up the chat bar, as it's a grid, the ListView will resize to fit the screen:
我更新输入栏的边距以推"它:
I update the input bar's margin to "push" it up:
NSValue result = (NSValue)args.Notification.UserInfo.ObjectForKey(new NSString(UIKeyboard.FrameEndUserInfoKey));
CGSize keyboardSize = result.RectangleFValue.Size;
if (Element != null){
Element.Margin = new Thickness(0, 0, 0,keyboardSize.Height); //push the entry up to keyboard height when keyboard is activated
}
结果如下:https://drive.google.com/file/d/1S9yQ6ks15BRH3hH0j_M8awjp/查看?usp=sharing
视图确实向上推并且 ListView 也按预期调整了大小,但是有两个问题我不知道如何解决:
The view did push up and the ListView also resized as expected, however there are two issues that I had no idea how to solve it:
- 如何在调整大小后保留 ListView 滚动位置?
- 缺乏向上推视图的动画
我在网上搜索过,尝试过 IQKeyboardManager 和 KeyboardOverLap,俯卧撑动画很好很流畅,但发生了奇怪的事情:
I have search over the web, tried IQKeyboardManager and KeyboardOverLap, The push up animation is nice and smooth, however strange things happened:
https://drive.google.com/file/d/1Zm0lMKB3wq07ve67wlcvLuNM_6Waad7R/view?usp=sharing
- 这种方法不是调整ListView的大小,而是将整个ListView向上推,看不到前几项,当然滚动条可以滚出屏幕
- ListView 底部的额外奇怪空格
任何帮助将不胜感激,谢谢!
Any help will be appreciated, thank you!
解决方案:
void OnKeyboardShow(object sender, UIKeyboardEventArgs args)
{
NSValue result = (NSValue)args.Notification.UserInfo.ObjectForKey(new NSString(UIKeyboard.FrameEndUserInfoKey));
CGSize keyboardSize = result.RectangleFValue.Size;
if (Control != null)
{
int bottomMargin = 0;
var sa = UIApplication.SharedApplication.KeyWindow.SafeAreaInsets;
bottomMargin = (int)sa.Bottom;
CGPoint offset = Control.ContentOffset;
var difference = keyboardSize.Height - bottomMargin;
if (Control.ContentSize.Height > Control.Frame.Height)
{
offset.Y += difference;
Control.SetContentOffset(offset, true);
}
else if (Control.ContentSize.Height + keyboardSize.Height > Control.Frame.Height)
{
offset.Y += Control.ContentSize.Height + keyboardSize.Height - Control.Frame.Height - bottomMargin;
Control.SetContentOffset(offset, true);
}
Control.ContentInset = new UIEdgeInsets(0, 0, difference, 0);
Control.ScrollIndicatorInsets = Control.ContentInset;
}
}
void OnKeyboardHide(object sender, UIKeyboardEventArgs args)
{
if (Control != null)
{
Control.ContentInset = new UIEdgeInsets(0, 0, 0, 0);
Control.ScrollIndicatorInsets = new UIEdgeInsets(0, 0, 0, 0);
}
}
推荐答案
解决方案:
参考以下代码
在 iOS 自定义渲染器中
in iOS Custom Renderer
protected override void OnElementChanged(ElementChangedEventArgs<ListView> e)
{
base.OnElementChanged(e);
if(Control!=null)
{
Control.KeyboardDismissMode = UIScrollViewKeyboardDismissMode.OnDrag;
NSNotificationCenter.DefaultCenter.AddObserver(this, new Selector("KeyBoardWillShow:"), new NSString("UIKeyboardWillShowNotification"), null);
NSNotificationCenter.DefaultCenter.AddObserver(this, new Selector("KeyBoardWillHide:"), new NSString("UIKeyboardWillHideNotification"), null);
}
}
[Export("KeyBoardWillShow:")]
void KeyBoardWillShow(NSNotification note)
{
NSValue keyboardRect = (NSValue)note.UserInfo.ObjectForKey(new NSString(UIKeyboard.FrameEndUserInfoKey));
Control.ContentInset = new UIEdgeInsets(0,0, keyboardRect.RectangleFValue.Size.Height,0);
}
[Export("KeyBoardWillHide:")]
void KeyBoardWillHide(NSNotification note)
{
Control.ContentInset = UIEdgeInsets.Zero;
}
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