我正在使用此示例代码创建一个简单的聊天。
这个例子没有NavigationController，一切正常。当键盘出现时，工具栏会向上移动。但是当我把它放在NavigationController中时，键盘不会移动（但是View会移动）。我尝试将textview inputAccessoryView设置为键盘，但无法正常工作。堆栈溢出中的其他解决方案涉及使用导航控制器的工具栏时。但这是一个自定义创建的工具栏...
感谢任何帮助...
public class ChatViewController : UIViewController
{
public MessageContacts chatWith;
NSObject willShowToken;
NSObject willHideToken;
List<Message> messages;
ChatSource chatSource;
UITableView tableView;
UIToolbar toolbar;
NSLayoutConstraint toolbarBottomConstraint;
NSLayoutConstraint toolbarHeightConstraint;
ChatInputView chatInputView;
UIButton SendButton
{
get
{
return chatInputView.SendButton;
}
}
UITextView TextView
{
get
{
return chatInputView.TextView;
}
}
bool IsInputToolbarHasReachedMaximumHeight
{
get
{
return toolbar.Frame.GetMinY() == TopLayoutGuide.Length;
}
}
public ChatViewController(IntPtr handle)
: base(handle)
{
messages = new List<Message>() {
new Message { Type = MessageType.Incoming, Text = "Hello!" },
new Message { Type = MessageType.Outgoing, Text = "Hi!" },
new Message { Type = MessageType.Incoming, Text = "Do you know about Xamarin?" },
new Message { Type = MessageType.Outgoing, Text = "Yes! Sure!" },
new Message { Type = MessageType.Incoming, Text = "And what do you think?" },
new Message { Type = MessageType.Outgoing, Text = "I think it is the best way to develop mobile applications." },
new Message { Type = MessageType.Incoming, Text = "Wow :-)" },
new Message { Type = MessageType.Outgoing, Text = "Yep. Check it out\nhttp://Xamarin.com" },
new Message { Type = MessageType.Incoming, Text = "Will do. Thanks" },
};
}
#region Life cycle
public override void ViewDidLoad()
{
base.ViewDidLoad();
Title = chatWith.name;
SetUpTableView();
SetUpToolbar();
SendButton.TouchUpInside += OnSendClicked;
TextView.Started += OnTextViewStarted;
TextView.Changed += OnTextChanged;
TextView.InputAccessoryView = toolbar;
}
public override void ViewWillAppear(bool animated)
{
base.ViewWillAppear(animated);
willShowToken = UIKeyboard.Notifications.ObserveWillShow(KeyboardWillShowHandler);
willHideToken = UIKeyboard.Notifications.ObserveWillHide(KeyboardWillHideHandler);
UpdateTableInsets();
UpdateButtonState();
ScrollToBottom(false);
}
public override void ViewDidAppear(bool animated)
{
base.ViewDidAppear(animated);
AddObservers();
}
#endregion
#region Initialization
void SetUpTableView()
{
tableView = new UITableView
{
TranslatesAutoresizingMaskIntoConstraints = false,
AllowsSelection = false,
SeparatorStyle = UITableViewCellSeparatorStyle.None,
};
tableView.RegisterClassForCellReuse(typeof(IncomingCell), IncomingCell.CellId);
tableView.RegisterClassForCellReuse(typeof(OutgoingCell), OutgoingCell.CellId);
View.AddSubview(tableView);
var pinLeft = NSLayoutConstraint.Create(tableView, NSLayoutAttribute.Leading, NSLayoutRelation.Equal, View, NSLayoutAttribute.Leading, 1f, 0f);
View.AddConstraint(pinLeft);
var pinRight = NSLayoutConstraint.Create(tableView, NSLayoutAttribute.Trailing, NSLayoutRelation.Equal, View, NSLayoutAttribute.Trailing, 1f, 0f);
View.AddConstraint(pinRight);
var pinTop = NSLayoutConstraint.Create(tableView, NSLayoutAttribute.Top, NSLayoutRelation.Equal, TopLayoutGuide, NSLayoutAttribute.Bottom, 1f, 0f);
View.AddConstraint(pinTop);
var pinBottom = NSLayoutConstraint.Create(tableView, NSLayoutAttribute.Bottom, NSLayoutRelation.Equal, View, NSLayoutAttribute.Bottom, 1f, 0f);
View.AddConstraint(pinBottom);
chatSource = new ChatSource(messages);
tableView.Source = chatSource;
}
void SetUpToolbar()
{
toolbar = new UIToolbar
{
TranslatesAutoresizingMaskIntoConstraints = false
};
chatInputView = new ChatInputView
{
TranslatesAutoresizingMaskIntoConstraints = false
};
View.AddSubview(toolbar);
var pinLeft = NSLayoutConstraint.Create(toolbar, NSLayoutAttribute.Leading, NSLayoutRelation.Equal, View, NSLayoutAttribute.Leading, 1f, 0f);
View.AddConstraint(pinLeft);
var pinRight = NSLayoutConstraint.Create(toolbar, NSLayoutAttribute.Trailing, NSLayoutRelation.Equal, View, NSLayoutAttribute.Trailing, 1f, 0f);
View.AddConstraint(pinRight);
toolbarBottomConstraint = NSLayoutConstraint.Create(View, NSLayoutAttribute.Bottom, NSLayoutRelation.Equal, toolbar, NSLayoutAttribute.Bottom, 1f, 0f);
View.AddConstraint(toolbarBottomConstraint);
toolbarHeightConstraint = NSLayoutConstraint.Create(toolbar, NSLayoutAttribute.Height, NSLayoutRelation.Equal, null, NSLayoutAttribute.NoAttribute, 0f, 44f);
View.AddConstraint(toolbarHeightConstraint);
toolbar.AddSubview(chatInputView);
var c1 = NSLayoutConstraint.FromVisualFormat("H:|[chat_container_view]|",
(NSLayoutFormatOptions)0,
"chat_container_view", chatInputView
);
var c2 = NSLayoutConstraint.FromVisualFormat("V:|[chat_container_view]|",
(NSLayoutFormatOptions)0,
"chat_container_view", chatInputView
);
toolbar.AddConstraints(c1);
toolbar.AddConstraints(c2);
}
#endregion
void AddObservers()
{
TextView.AddObserver(this, "contentSize", NSKeyValueObservingOptions.OldNew, IntPtr.Zero);
}
public override void ObserveValue(NSString keyPath, NSObject ofObject, NSDictionary change, IntPtr context)
{
if (keyPath == "contentSize")
OnSizeChanged(new NSObservedChange(change));
else
base.ObserveValue(keyPath, ofObject, change, context);
}
void OnSizeChanged(NSObservedChange change)
{
CGSize oldValue = ((NSValue)change.OldValue).CGSizeValue;
CGSize newValue = ((NSValue)change.NewValue).CGSizeValue;
var dy = newValue.Height - oldValue.Height;
AdjustInputToolbarOnTextViewSizeChanged(dy);
}
void AdjustInputToolbarOnTextViewSizeChanged(nfloat dy)
{
bool isIncreasing = dy > 0;
if (IsInputToolbarHasReachedMaximumHeight && isIncreasing)
{
// TODO: scroll to bottom
return;
}
nfloat oldY = toolbar.Frame.GetMinY();
nfloat newY = oldY - dy;
if (newY < TopLayoutGuide.Length)
dy = oldY - TopLayoutGuide.Length;
AdjustInputToolbar(dy);
}
void AdjustInputToolbar(nfloat change)
{
toolbarHeightConstraint.Constant += change;
if (toolbarHeightConstraint.Constant < ChatInputView.ToolbarMinHeight)
toolbarHeightConstraint.Constant = ChatInputView.ToolbarMinHeight;
View.SetNeedsUpdateConstraints();
View.LayoutIfNeeded();
}
void KeyboardWillShowHandler(object sender, UIKeyboardEventArgs e)
{
UpdateButtomLayoutConstraint(e);
}
void KeyboardWillHideHandler(object sender, UIKeyboardEventArgs e)
{
UpdateButtomLayoutConstraint(e);
}
void UpdateButtomLayoutConstraint(UIKeyboardEventArgs e)
{
UIViewAnimationCurve curve = e.AnimationCurve;
UIView.Animate(e.AnimationDuration, 0, ConvertToAnimationOptions(e.AnimationCurve), () =>
{
nfloat offsetFromBottom = tableView.Frame.GetMaxY() - e.FrameEnd.GetMinY();
offsetFromBottom = NMath.Max(0, offsetFromBottom);
SetToolbarContstraint(offsetFromBottom);
}, null);
}
void SetToolbarContstraint(nfloat constant)
{
toolbarBottomConstraint.Constant = constant;
View.SetNeedsUpdateConstraints();
View.LayoutIfNeeded();
UpdateTableInsets();
}
void UpdateTableInsets()
{
nfloat bottom = tableView.Frame.GetMaxY() - toolbar.Frame.GetMinY();
UIEdgeInsets insets = new UIEdgeInsets(0f, 0f, bottom, 0f);
tableView.ContentInset = insets;
tableView.ScrollIndicatorInsets = insets;
}
UIViewAnimationOptions ConvertToAnimationOptions(UIViewAnimationCurve curve)
{
// Looks like a hack. But it is correct.
// UIViewAnimationCurve and UIViewAnimationOptions are shifted by 16 bits
// http://stackoverflow.com/questions/18870447/how-to-use-the-default-ios7-uianimation-curve/18873820#18873820
return (UIViewAnimationOptions)((int)curve << 16);
}
void OnSendClicked(object sender, EventArgs e)
{
var text = TextView.Text;
TextView.Text = string.Empty; // this will not generate change text event
UpdateButtonState();
if (string.IsNullOrWhiteSpace(text))
return;
var msg = new Message
{
Type = MessageType.Outgoing,
Text = text.Trim()
};
messages.Add(msg);
tableView.InsertRows(new NSIndexPath[] { NSIndexPath.FromRowSection(messages.Count - 1, 0) }, UITableViewRowAnimation.None);
ScrollToBottom(true);
}
void OnTextViewStarted(object sender, EventArgs e)
{
ScrollToBottom(true);
}
void OnTextChanged(object sender, EventArgs e)
{
UpdateButtonState();
}
void UpdateButtonState()
{
SendButton.Enabled = !string.IsNullOrWhiteSpace(TextView.Text);
}
public override void ViewWillDisappear(bool animated)
{
base.ViewWillDisappear(animated);
willShowToken.Dispose();
willHideToken.Dispose();
}
void ScrollToBottom(bool animated)
{
if (tableView.NumberOfSections() == 0)
return;
int items = (int)tableView.NumberOfRowsInSection(0);
if (items == 0)
return;
int finalRow = (int)NMath.Max(0, tableView.NumberOfRowsInSection(0) - 1);
NSIndexPath finalIndexPath = NSIndexPath.FromRowSection(finalRow, 0);
tableView.ScrollToRow(finalIndexPath, UITableViewScrollPosition.Top, animated);
}
}
答案 0 :(得分：0)
这个样本真的很糟糕，有很多bug。
对于键盘问题，我建议您使用这些代码：
在ViewDidLoad中首次注册事件：
public override void ViewDidLoad ()
{
//Smaples codes
base.ViewDidLoad ();
SetUpTableView ();
SetUpToolbar ();
SendButton.TouchUpInside += OnSendClicked;
TextView.Started += OnTextViewStarted;
TextView.Changed += OnTextChanged;
//Create by me
this.View.AddGestureRecognizer(new UITapGestureRecognizer(()=>{
this.View.EndEditing(true);
}));
NSNotificationCenter.DefaultCenter.AddObserver(this,new ObjCRuntime.Selector("keyboardWillShow:"),UIKeyboard.WillShowNotification,null);
NSNotificationCenter.DefaultCenter.AddObserver(this,new ObjCRuntime.Selector("keyboardWillHide:"),UIKeyboard.WillHideNotification,null);
}
然后使用它们处理键盘事件：
[Action("keyboardWillShow:")]
private void KeyboardWillShow(NSNotification notification)
{
NSDictionary info = notification.UserInfo;
CGSize kbSize = (info.ObjectForKey(UIKeyboard.FrameEndUserInfoKey) as NSValue).CGRectValue.Size;
nfloat keyboardHeight = kbSize.Height;
CGRect tmpR = this.View.Frame;
tmpR.Y -= keyboardHeight;
this.View.Frame = tmpR;
}
[Action("keyboardWillHide:")]
private void KeyboardWillHide(NSNotification notification)
{
this.View.Frame = UIScreen.MainScreen.Bounds;
}
有一个非常简单的聊天视图模型我以前写过另一个，由Objective-C制作，你可以看看，非常简单。
希望它可以帮助你，如果你仍然需要一些帮助，就把它放在这里，我会检查它。