视图框内的WPF TextBox在调整大小时丢失游标 [英] WPF TextBox Inside ViewBox loses Cursor on resize
问题描述
我在视图框内有一个文本框.当我尝试调整窗口大小时，文本框的大小和字体大小会变大，但是如果我尝试聚焦文本框并尝试使用键盘在文本框内移动光标，则有时光标会消失.有没有一种方法可以始终显示光标?请参考下面的代码，其中ViewBox里面是一个TextBox.
I have a textbox inside a viewbox. When I try to resize the window, the textbox size and font size getting scaled, but if I try to focus the textbox and try move the cursor inside the textbox using keyboard, sometimes the cursor is getting disappeared. Is there a way to show the cursor always? Refer the below code which a TextBox inside ViewBox.
<Window x:Class="Resolution_Learning.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow">
<Viewbox Stretch="Uniform">
<Grid Width="2560" Height="1440" >
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Label Grid.Row="0" Grid.Column="0" Content="Hello"/>
<TextBox Grid.Row="0" Grid.Column="1"></TextBox>
<Label Grid.Row="0" Grid.Column="2" Content="Hello"/>
<TextBox Grid.Row="0" Grid.Column="3"/>
<Label Grid.Row="1" Grid.Column="0" Content="Hello"/>
<TextBox Grid.Row="1" Grid.Column="1"/>
<Label Grid.Row="1" Grid.Column="2" Content="Hello"/>
<TextBox Grid.Row="1" Grid.Column="3"/>
</Grid>
</Viewbox>
推荐答案
It's a BUG in WPF. I achieved this by creating my own style for TextBox Caret.
XAML: Style for TextBox
<Style TargetType="{x:Type TextBox}" x:Key="CaretStyle" >
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<Canvas>
<TextBox x:Name="Box" CaretBrush="Transparent" Width="{Binding RelativeSource={RelativeSource AncestorType=TextBox},Path=ActualWidth,Mode=OneWay}"
Height="{Binding RelativeSource={RelativeSource AncestorType=TextBox},Path=ActualHeight,Mode=OneWay}"/>
<Border x:Name="Caret"
Visibility="Collapsed"
Canvas.Left="0" Canvas.Top="0" Margin="0" Padding="0"
Width="1" Height="16" Background="Black">
<Border.Triggers>
<EventTrigger RoutedEvent="Border.Loaded">
<BeginStoryboard>
<Storyboard x:Name="CaretStoryBoard"
RepeatBehavior="Forever">
<ColorAnimationUsingKeyFrames
Storyboard.TargetProperty="Background.Color"
Duration="0:0:0:1"
FillBehavior="HoldEnd">
<ColorAnimationUsingKeyFrames.KeyFrames >
<DiscreteColorKeyFrame KeyTime="0:0:0.750"
Value="Transparent" />
<DiscreteColorKeyFrame KeyTime="0:0:0.000"
Value="Black"/>
</ColorAnimationUsingKeyFrames.KeyFrames>
</ColorAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Border.Triggers>
</Border>
</Canvas>
</ControlTemplate>
</Setter.Value>
</Setter>
<EventSetter Event="SelectionChanged" Handler="CustomTextBox_SelectionChanged"/>
<EventSetter Event="GotFocus" Handler="CustomTextBox_GotFocus" />
<EventSetter Event="LostFocus" Handler="CustomTextBox_LostFocus" />
</Style>
事件: For Caret Position
void CustomTextBox_LostFocus(object sender, RoutedEventArgs e)
{
var Caret = FindChild<Border>(sender as DependencyObject, "Caret");
Caret.Visibility = Visibility.Collapsed;
}
void CustomTextBox_GotFocus(object sender, RoutedEventArgs e)
{
var Caret = FindChild<Border>(sender as DependencyObject, "Caret");
Caret.Visibility = Visibility.Visible;
}
void CustomTextBox_SelectionChanged(object sender, RoutedEventArgs e)
{
var CustomTextBox = FindChild<TextBox>(sender as DependencyObject, "Box");
var caretLocation = CustomTextBox.GetRectFromCharacterIndex(CustomTextBox.CaretIndex).Location;
var Caret = FindChild<Border>(sender as DependencyObject, "Caret");
if (!double.IsInfinity(caretLocation.X))
{
Canvas.SetLeft(Caret, caretLocation.X);
}
if (!double.IsInfinity(caretLocation.Y))
{
Canvas.SetTop(Caret, caretLocation.Y);
}
}
帮助器方法: To Get Visual Child
public static T FindChild<T>(DependencyObject parent, string childName)
where T : DependencyObject
{
// Confirm parent and childName are valid.
if (parent == null) return null;
T foundChild = null;
int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < childrenCount; i++)
{
var child = VisualTreeHelper.GetChild(parent, i);
// If the child is not of the request child type child
T childType = child as T;
if (childType == null)
{
// recursively drill down the tree
foundChild = FindChild<T>(child, childName);
// If the child is found, break so we do not overwrite the found child.
if (foundChild != null) break;
}
else if (!string.IsNullOrEmpty(childName))
{
var frameworkElement = child as FrameworkElement;
// If the child's name is set for search
if (frameworkElement != null && frameworkElement.Name == childName)
{
// if the child's name is of the request name
foundChild = (T)child;
break;
}
}
else
{
// child element found.
foundChild = (T)child;
break;
}
}
return foundChild;
}
只需在代码中添加
Style/metods上方，然后将Style设置为TextBoxes任意位置，即可查看结果.正如我创造的 我自己并没有对Caret symbol进行任何实际测量，因此您可能会在一定程度上看到阴影.请调整 外观感觉需要.
Just add above
Style/metodsin your code and setStyleforTextBoxeswherever you want and see the result. As I have created this myself without any actual measurement of actualCaret symbol, you may see a light shadow at some scale. please adjust the look & feel as needed.
这篇关于视图框内的WPF TextBox在调整大小时丢失游标的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
