Question

我有一个WPF应用程序，其中有一个使用墨水画布控件的签名页。我有一个非常随机的问题，某些笔划无法在笔划集合中收集并消失。我知道软件中的“随机”一词是忌讳的，但请相信我的随机性。没有多线程发生。

使用鼠标和触摸输入也会发生此问题。

目前尚不清楚源代码是否会有所帮助，但是无论如何我都会将其放在下面

SignatureForm.cs

    public partial class SignatureForm : UserControl
        {
            public event EventHandler SubmitButtonClick;

            private byte[] _signatureBytes;
            public byte[] SignatureBytes
            {
                get
                {
                     _signatureBytes = SignatureHelper.GetStrokeBytes(SignatureCanvas.Strokes, SignatureCanvas);

                    return _signatureBytes;
                }
                private set => _signatureBytes = value;
            }

            private Bitmap _signatureImage;

            public Bitmap SignatureImage
            {
                get
                {
                    _signatureImage = SignatureHelper.GetSignatureImage(SignatureCanvas);
                    return _signatureImage;
                }
                private set => _signatureImage = value;
            }

            public SignatureForm()
            {
                InitializeComponent();
                ClearButton.Visibility = Visibility.Hidden;
                PlaceholderText.Visibility = Visibility.Visible;
                AcceptButton.Visibility = Visibility.Hidden;
            }

            private void SubmitButton_TouchUp(object sender, TouchEventArgs e)
            {
                if (TouchIndicator.IsTouchEnabled)
                    SubmitButtonClick?.Invoke(sender, e);
            }

            private void SubmitButton_MouseUp(object sender, MouseButtonEventArgs e)
            {
                if (!TouchIndicator.IsTouchEnabled)
                    SubmitButtonClick?.Invoke(sender, e);
            }

            private void ClearButton_OnMouseUp(object sender, MouseButtonEventArgs e)
            {
                Clear();
            }

            private void ClearButton_OnTouchUp(object sender, TouchEventArgs e)
            {
                Clear();
            }

            private void Clear()
            {
                SignatureCanvas.Strokes.Clear();
                SubmitHide();
            }

            private void SignatureCanvas_OnStrokeCollected(object sender, InkCanvasStrokeCollectedEventArgs e)
            {
                SubmitReveal();
            }

            private void SignatureCanvas_OnTouchDown(object sender, TouchEventArgs e)
            {
                SubmitReveal();
            }

            private void SubmitReveal()
            {
                ClearButton.Visibility = Visibility.Visible;
                PlaceholderText.Visibility = Visibility.Hidden;
                AcceptButton.Visibility = Visibility.Visible;
            }

            private void SubmitHide()
            {
                ClearButton.Visibility = Visibility.Hidden;
                PlaceholderText.Visibility = Visibility.Visible;
                AcceptButton.Visibility = Visibility.Hidden;
            }

            private void SignatureCanvas_OnTouchUp(object sender, TouchEventArgs e)
            {
                if (SignatureCanvas.Strokes.Count == 0) SubmitHide();
            }
        }

SignatureForm.cs.xaml

        <Grid x:Name="SignatureGrid">
            <Grid.RowDefinitions>
                <RowDefinition Height=".75*" />
                <RowDefinition Height=".25*" />
            </Grid.RowDefinitions>
            <Border Grid.Row="0" BorderThickness="2" BorderBrush="{DynamicResource DarkBlue}">
                <Grid>
                    <TextBlock x:Name="PlaceholderText" Style="{StaticResource SignHereText}" Text="Sign here with your finger"/>
                    <InkCanvas x:Name="SignatureCanvas" Style="{StaticResource SignatureCanvas}" StrokeCollected="SignatureCanvas_OnStrokeCollected" TouchDown="SignatureCanvas_OnTouchDown" TouchUp="SignatureCanvas_OnTouchUp" />
                </Grid>
            </Border>
            <Border Grid.Row="0" x:Name="ClearButton" Style="{StaticResource ClearSignatureButton}"
                    MouseUp="ClearButton_OnMouseUp" TouchUp="ClearButton_OnTouchUp">
                <TextBlock x:Name="ButtonText" Text="CLEAR" Style="{StaticResource ClearSignatureText}" />
            </Border>
            <Border Grid.Row="1" BorderThickness="0" BorderBrush="{DynamicResource Teal}" Margin="0 0 0 0"
                    MouseUp="SubmitButton_MouseUp" TouchUp="SubmitButton_TouchUp">
                <TextBlock x:Name="AcceptButton" Style="{DynamicResource SubmitText}">Tap here to submit</TextBlock>
            </Border>
        </Grid>

Answer 1

所以我发现了这个问题，有一个属性EditingMode设置为“ InkAndGesture”，删除该属性后，InkCanvas可以正常工作并收集所有笔画。

        <Style x:Key="SignatureCanvas" TargetType="InkCanvas">
            <Setter Property="Background" Value="{DynamicResource Transparent}" />
            <!--<Setter Property="EditingMode" Value="InkAndGesture"/>-->
            <Setter Property="DefaultDrawingAttributes">
                <Setter.Value>
                    <DrawingAttributes Width="10" Height="10"/>
                </Setter.Value>
            </Setter>
        </Style>

WPF InkCanvas-未收集某些笔画

1 个答案: