保存从墨水画布图像(save an image from ink canvas)

我试图挽救墨迹画布图像但它不会产生储蓄之后的任何文件，这是我的代码

RenderTargetBitmap rtb = new RenderTargetBitmap(
    (int)canvas.Width, (int)canvas.Height, 0, 0, PixelFormats.Default);

rtb.Render(this.canvas);

JpegBitmapEncoder encoder = new JpegBitmapEncoder();

encoder.Frames.Add(BitmapFrame.Create(rtb));

using(var file = new FileStream(@"C:\test.jpg", FileMode.Create))
{
   encoder.Save(file);
}

然而，当我改变了目录甚至没有创建任何文件。 无例外被调用并且没有显示错误。 该代码只是正常运行，没有任何问题，但该文件意味着要产生是不存在的。

Answer 1:

尝试使用保存文件对话框

下面是我在我的课“添加签名”在vb.net中使用的示例代码

在按钮单击SAVEFILE会出现对话框，把一个文件名，然后按保存后，将保存为png图像（我用pngBitmap编码器）

这与你使用的是什么，但添加了一个保存文件对话框相同的格式。

顺便说一句。 WPFControl.Inkcanvas1是我inkcanvas

'buttonSaveAsClick


   'open save file dialog box
    Dim sfd As New SaveFileDialog()
    sfd.Filter = "Png Files(*.png)|*.png"

    'save file as png (render bitmap and convert/save to png)
    Dim result As Nullable(Of Boolean) = sfd.ShowDialog()
    Dim fileName As String = ""

    If result = True Then
        fileName = sfd.FileName

        Dim size As Size = New Point(750, 400) '= WPFControl.InkCanvas1.RenderSize 
        Console.WriteLine(WPFControl.InkCanvas1.RenderSize)
        Dim rtb As New RenderTargetBitmap(CInt(size.Width), CInt(size.Height), 96, 96, Windows.Media.PixelFormats.Pbgra32)
        rtb.Render(WPFControl.InkCanvas1)
        Dim png As New PngBitmapEncoder()
        png.Frames.Add(BitmapFrame.Create(rtb))
        If String.IsNullOrEmpty(fileName) = True Then
            MsgBox("Please Enter a File Name", MsgBoxStyle.Exclamation, "File Name required!")
            Exit Sub

        Else
            Console.WriteLine(sfd.FileName)
            Console.WriteLine(convertImage.ConvertImageFiletoBytes(sfd.FileName))
        End If


        Using stm As Stream = File.Create(fileName)
            png.Save(stm)

        End Using
    End If

Answer 2:

<Window x:Class="WpfInkCavasSaveImage.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow"  Height="1091" Width="873" WindowState="Maximized">
    <Grid Margin="0,0,0,173" >
        <Grid.RowDefinitions>
            <RowDefinition Height="1200*" />
            <RowDefinition Height="50" />
        </Grid.RowDefinitions>    
        <InkCanvas HorizontalAlignment="Stretch" Margin="1,1,1,10" x:Name="inkCanvas1" VerticalAlignment="Stretch" Width="Auto" RenderTransformOrigin="0.5,0.5" Background="LightGreen" SnapsToDevicePixels="True" IsManipulationEnabled ="True"  Grid.RowSpan="2">
            <InkCanvas.CacheMode>
                <BitmapCache/>
            </InkCanvas.CacheMode>
            <InkCanvas.DefaultDrawingAttributes>
                <DrawingAttributes Color="Black" FitToCurve="True" Height="2.0031496062992127" IgnorePressure="False" IsHighlighter="False" StylusTip="Ellipse" StylusTipTransform="Identity" Width="2.0031496062992127"/>    
            </InkCanvas.DefaultDrawingAttributes>
        </InkCanvas>
        <Button x:Name="btnSaveImage" Content="Save Ink Canvas" Height="41" Width="155" Canvas.Left="100" Canvas.Top="900"  VerticalAlignment="Top" HorizontalAlignment="Left" RenderTransformOrigin="1.417,14.6" Margin="15,93,0,-84" Background="SkyBlue" Click="btnSaveInkCanvas" Grid.Row="1" BorderBrush="{x:Null}"/>
    </Grid>

</Window>


using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.AccessControl;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfInkCavasSaveImage
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            inkCanvas1.Width = System.Windows.SystemParameters.WorkArea.Width;
            inkCanvas1.Height = System.Windows.SystemParameters.WorkArea.Height;
        }
        private void btnSaveInkCanvas(object sender, RoutedEventArgs e)
        {
            string subpath = Directory.GetCurrentDirectory();
            SaveFileDialog saveFileDialog12 = new SaveFileDialog();
            saveFileDialog12.Filter = "JPeg Image|*.jpg|Bitmap Image|*.bmp|Gif Image|*.gif|Png File|*.png";
            saveFileDialog12.Title = "Save an Image File";
            saveFileDialog12.InitialDirectory = subpath;
            saveFileDialog12.ShowDialog();

            if (saveFileDialog12.FileName == "") return;
            subpath = saveFileDialog12.FileName.Substring(0, saveFileDialog12.FileName.Length - saveFileDialog12.SafeFileName.Length);

            RenderTargetBitmap rtb = new RenderTargetBitmap((int)inkCanvas1.Width, (int)inkCanvas1.Height, 96d, 96d, PixelFormats.Default);
            rtb.Render(inkCanvas1);
            DrawingVisual dvInk = new DrawingVisual();
            DrawingContext dcInk = dvInk.RenderOpen();
            dcInk.DrawRectangle(inkCanvas1.Background, null, new Rect(0d, 0d, inkCanvas1.Width, inkCanvas1.Height));
            foreach (System.Windows.Ink.Stroke stroke in inkCanvas1.Strokes)
            {
                stroke.Draw(dcInk);
            }
            dcInk.Close();

            FileStream fs = File.Open(saveFileDialog12.FileName, FileMode.OpenOrCreate);//save bitmap to file
            System.Windows.Media.Imaging.JpegBitmapEncoder encoder1 = new JpegBitmapEncoder();
            encoder1.Frames.Add(BitmapFrame.Create(rtb));
            encoder1.Save(fs);
            fs.Close();
        }
    }
}

文章来源: save an image from ink canvas