背水一战 Windows 10 (62) - 控件(媒体类): InkCanvas 保存和加载, 手写识别

2023-05-16,,

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背水一战 Windows 10 (62) - 控件(媒体类): InkCanvas 保存和加载, 手写识别

作者:webabcd

介绍
背水一战 Windows 10 之 控件(媒体类)

InkCanvas 保存和加载
InkCanvas 手写识别

示例
1、演示 InkCanvas 涂鸦板的保存和加载
Controls/MediaControl/InkCanvasDemo3.xaml

<Page
x:Class="Windows10.Controls.MediaControl.InkCanvasDemo3"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Windows10.Controls.MediaControl"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"> <Grid Background="Transparent">
<StackPanel Margin="10 0 10 10"> <Border Background="White" Width="480" Height="320" Margin="5" HorizontalAlignment="Left">
<!--
InkCanvas - 涂鸦板控件
-->
<InkCanvas Name="inkCanvas" />
</Border> <Button Name="save" Content="保存到文件" Margin="5" Click="save_Click" />
<Button Name="load" Content="从文件读取" Margin="5" Click="load_Click" /> </StackPanel>
</Grid>
</Page>

Controls/MediaControl/InkCanvasDemo3.xaml.cs

/*
* InkCanvas - 涂鸦板控件(继承自 FrameworkElement, 请参见 /Controls/BaseControl/FrameworkElementDemo/)
* InkPresenter - 获取 InkPresenter 对象
*
* InkPresenter - 涂鸦板
* StrokeContainer - 返回 InkStrokeContainer 类型的对象
*
* InkStrokeContainer - 用于管理涂鸦
* IAsyncOperationWithProgress<UInt32, UInt32> SaveAsync(IOutputStream outputStream) - 保存涂鸦数据
* IAsyncActionWithProgress<UInt64> LoadAsync(IInputStream inputStream) - 加载涂鸦数据
*/ using System;
using System.Collections.Generic;
using Windows.Foundation;
using Windows.Storage;
using Windows.Storage.Pickers;
using Windows.Storage.Streams;
using Windows.UI;
using Windows.UI.Core;
using Windows.UI.Input.Inking;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls; namespace Windows10.Controls.MediaControl
{
public sealed partial class InkCanvasDemo3 : Page
{
public InkCanvasDemo3()
{
this.InitializeComponent(); inkCanvas.InkPresenter.InputDeviceTypes = CoreInputDeviceTypes.Mouse | CoreInputDeviceTypes.Pen | CoreInputDeviceTypes.Touch; InkDrawingAttributes drawingAttributes = inkCanvas.InkPresenter.CopyDefaultDrawingAttributes();
drawingAttributes.IgnorePressure = true;
drawingAttributes.Color = Colors.Red;
drawingAttributes.Size = new Size(, );
inkCanvas.InkPresenter.UpdateDefaultDrawingAttributes(drawingAttributes);
} private async void save_Click(object sender, RoutedEventArgs e)
{
if (inkCanvas.InkPresenter.StrokeContainer.GetStrokes().Count == )
return; // 用于保存涂鸦数据
IRandomAccessStream stream = new InMemoryRandomAccessStream();
await inkCanvas.InkPresenter.StrokeContainer.SaveAsync(stream); // 文件保存对话框
var picker = new FileSavePicker
{
SuggestedStartLocation = PickerLocationId.DocumentsLibrary
};
picker.FileTypeChoices.Add("ink files", new List<string>() { ".ink" }); // 弹出文件保存对话框
var file = await picker.PickSaveFileAsync();
if (file == null)
return; // 在调用 CompleteUpdatesAsync 之前,阻止对文件的更新
CachedFileManager.DeferUpdates(file); // Stream 转 byte[]
DataReader reader = new DataReader(stream.GetInputStreamAt());
await reader.LoadAsync((uint)stream.Size);
byte[] bytes = new byte[stream.Size];
reader.ReadBytes(bytes); // 写入文件
await FileIO.WriteBytesAsync(file, bytes); // 保存文件
await CachedFileManager.CompleteUpdatesAsync(file);
} private async void load_Click(object sender, RoutedEventArgs e)
{
// 文件打开对话框
var picker = new FileOpenPicker
{
SuggestedStartLocation = PickerLocationId.DocumentsLibrary
};
picker.FileTypeFilter.Add(".ink"); // 弹出文件打开对话框
var pickedFile = await picker.PickSingleFileAsync();
if (pickedFile != null)
{
// 读取涂鸦数据
IRandomAccessStreamWithContentType stream = await pickedFile.OpenReadAsync(); // 加载指定的涂鸦数据
await inkCanvas.InkPresenter.StrokeContainer.LoadAsync(stream);
}
}
}
}

2、演示 InkCanvas 涂鸦板的手写识别
Controls/MediaControl/InkCanvasDemo4.xaml

<Page
x:Class="Windows10.Controls.MediaControl.InkCanvasDemo4"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Windows10.Controls.MediaControl"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"> <Grid Background="Transparent">
<StackPanel Margin="10 0 10 10"> <Border Background="White" Width="480" Height="320" Margin="5" HorizontalAlignment="Left">
<!--
InkCanvas - 涂鸦板控件
-->
<InkCanvas Name="inkCanvas" />
</Border> <Button Name="recognize" Content="手写识别" Margin="5" Click="recognize_Click" /> <TextBlock Name="lblMsg" Margin="5" /> </StackPanel>
</Grid>
</Page>

Controls/MediaControl/InkCanvasDemo4.xaml.cs

/*
* InkCanvas - 涂鸦板控件(继承自 FrameworkElement, 请参见 /Controls/BaseControl/FrameworkElementDemo/)
* InkPresenter - 获取 InkPresenter 对象
*
* InkRecognizerContainer - 用于管理手写识别
* GetRecognizers() - 获取 InkRecognizer 对象集合
* SetDefaultRecognizer(InkRecognizer recognizer) - 将指定的 InkRecognizer 设置为默认的手写识别器
* RecognizeAsync(InkStrokeContainer strokeCollection, InkRecognitionTarget recognitionTarget) - 识别,返回 InkRecognitionResult 对象集合
* InkStrokeContainer strokeCollection - 需要识别的 InkStrokeContainer 对象
* InkRecognitionTarget recognitionTarget - 需要识别的目标
* All - 识别全部涂鸦数据
* Selected - 识别被选中的涂鸦数据
* Recent - 识别 InkStroke 的 Recognized 为 false 的涂鸦数据
*
* InkRecognizer - 手写识别器
* Name - 手写识别器的名字(只读)
*
* InkRecognitionResult - 手写识别结果
* BoundingRect - 获取用于识别的涂鸦的 Rect 区域
* GetStrokes() - 获取用于识别的 InkStroke 对象集合
* GetTextCandidates() - 获取识别结果,这是一个候选结果列表
*
* InkPresenter - 涂鸦板
* StrokeContainer - 返回 InkStrokeContainer 类型的对象
*
* InkStrokeContainer - 用于管理涂鸦
* UpdateRecognitionResults(IReadOnlyList<InkRecognitionResult> recognitionResults) - 将指定的识别结果通知给 InkStrokeContainer(此时 InkStrokeContainer 中被识别的 InkStroke 的 Recognized 将被标记为 true)
* 如果使用的是 InkRecognitionTarget.All 则 InkStrokeContainer 中的所有的 InkStroke 的 Recognized 将被标记为 true
* 如果使用的是 InkRecognitionTarget.Selected 则 InkStrokeContainer 中的被选中的 InkStroke 的 Recognized 将被标记为 true
* GetRecognitionResults() - 返回之前通过 UpdateRecognitionResults 方法设置的数据
*
* InkStroke - 涂鸦对象(这是一次的涂鸦对象,即鼠标按下后移动然后再抬起后所绘制出的涂鸦)
* Recognized - 此 InkStroke 是否被识别了
* Selected - 此 InkStroke 是否被选中了
*/ using System;
using System.Collections.Generic;
using System.Diagnostics;
using Windows.Foundation;
using Windows.UI;
using Windows.UI.Core;
using Windows.UI.Input.Inking;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls; namespace Windows10.Controls.MediaControl
{
public sealed partial class InkCanvasDemo4 : Page
{
public InkCanvasDemo4()
{
this.InitializeComponent(); inkCanvas.InkPresenter.InputDeviceTypes = CoreInputDeviceTypes.Mouse | CoreInputDeviceTypes.Pen | CoreInputDeviceTypes.Touch; InkDrawingAttributes drawingAttributes = inkCanvas.InkPresenter.CopyDefaultDrawingAttributes();
drawingAttributes.IgnorePressure = true;
drawingAttributes.Color = Colors.Red;
drawingAttributes.Size = new Size(, );
inkCanvas.InkPresenter.UpdateDefaultDrawingAttributes(drawingAttributes);
} private async void recognize_Click(object sender, RoutedEventArgs e)
{
if (inkCanvas.InkPresenter.StrokeContainer.GetStrokes().Count == )
return; InkRecognizerContainer container = new InkRecognizerContainer(); lblMsg.Text = "手写识别器: ";
lblMsg.Text += Environment.NewLine;
// 获取当前支持的手写识别器列表,如果有多个的话可以通过 SetDefaultRecognizer 方法来指定默认的手写识别器
IReadOnlyList<InkRecognizer> recognizers = container.GetRecognizers();
foreach (InkRecognizer ir in recognizers)
{
lblMsg.Text += ir.Name;
lblMsg.Text += Environment.NewLine;
} lblMsg.Text += Environment.NewLine;
lblMsg.Text += "识别结果: ";
lblMsg.Text += Environment.NewLine;
IReadOnlyList<InkRecognitionResult> result = await container.RecognizeAsync(inkCanvas.InkPresenter.StrokeContainer, InkRecognitionTarget.All);
foreach (string textCandidate in result[].GetTextCandidates())
{
lblMsg.Text += textCandidate;
lblMsg.Text += Environment.NewLine;
} // 将识别结果通知给 InkStrokeContainer
inkCanvas.InkPresenter.StrokeContainer.UpdateRecognitionResults(result); // 识别结果通知给 InkStrokeContainer 后,被识别的 InkStroke 的 Recognized 将被标记为 true
// 如果在识别的时候使用的是 InkRecognitionTarget.All 则所有的 InkStroke 的 Recognized 将被标记为 true
// 如果在识别的时候使用的是 InkRecognitionTarget.Selected 则被选中的 InkStroke 的 Recognized 将被标记为 true
IReadOnlyList<InkStroke> strokes = inkCanvas.InkPresenter.StrokeContainer.GetStrokes();
foreach (InkStroke stroke in strokes)
{
Debug.WriteLine("stroke.Recognized: " + stroke.Recognized);
} // 这个获取到的就是之前通过 InkStrokeContainer 方式设置的数据
result = inkCanvas.InkPresenter.StrokeContainer.GetRecognitionResults();
}
}
}

OK
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