我正在尝试创建一个允许用户在图像上绘图的应用程序。我从 PhotoPaint SDK 示例开始。我了解 SurfaceInkCanvas 设置为透明并位于图像顶部。当用户完成绘图时,我想将笔画绘制到图像本身上。这就是我卡住的地方。谁能指出我正确的方向?
谢谢!
我正在尝试创建一个允许用户在图像上绘图的应用程序。我从 PhotoPaint SDK 示例开始。我了解 SurfaceInkCanvas 设置为透明并位于图像顶部。当用户完成绘图时,我想将笔画绘制到图像本身上。这就是我卡住的地方。谁能指出我正确的方向?
谢谢!
从以下网址下载 WriteableBitmap 扩展库: http ://writeablebitmapex.codeplex.com/
用法:
using System;
using System.IO;
using System.Net;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;
namespace TestApp
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void SaveImage(object sender, RoutedEventArgs e)
{
var bi = FromUrl("http://www.dynamicdrive.com/dynamicindex4/lightbox2/horses.jpg", Environment.CurrentDirectory);
if (bi.Format != PixelFormats.Pbgra32)
bi = BitmapFactory.ConvertToPbgra32Format(bi);
WriteableBitmap wrb = new WriteableBitmap(bi);
foreach (var stroke in ink.Strokes)
{
foreach (var point in stroke.StylusPoints)
{
wrb.DrawLine((int)point.X, (int)point.Y, (int)(point.X + 1), (int)(point.Y + 1), Colors.Red);
}
}
var encoder = new JpegBitmapEncoder();
BitmapFrame frame = BitmapFrame.Create(wrb);
encoder.Frames.Add(frame);
using (var stream = File.Create("result.jpg"))
{
encoder.Save(stream);
}
}
public static BitmapSource FromUrl(string url, string workingPath)
{
string[] strArr = url.Split(new char[] { '/' });
string file = workingPath + "\\" + strArr[strArr.Length - 1];
if (!File.Exists(file))
{
using (WebClient client = new WebClient())
{
client.DownloadFile(url, file);
}
}
return BitmapImageFromFile(file);
}
public static BitmapSource BitmapImageFromFile(string file)
{
BitmapImage bi = new BitmapImage();
try
{
bi.BeginInit();
bi.CacheOption = BitmapCacheOption.OnLoad;
bi.CreateOptions = BitmapCreateOptions.IgnoreImageCache;
bi.UriSource = new Uri(file, UriKind.RelativeOrAbsolute);
bi.EndInit();
}
catch { return ToBitmapSource(System.Drawing.Bitmap.FromFile(file)); }
return bi;
}
public static BitmapSource ToBitmapSource(System.Drawing.Image bitmap)
{
using (MemoryStream stream = new MemoryStream())
{
bitmap.Save(stream, System.Drawing.Imaging.ImageFormat.Jpeg);
stream.Position = 0;
BitmapImage result = new BitmapImage();
result.BeginInit();
result.CacheOption = BitmapCacheOption.OnLoad;
result.StreamSource = stream;
result.EndInit();
result.Freeze();
return result;
}
}
}
}
XAML:
<Window x:Class="TestApp.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow"
Height="350" Width="525">
<Grid>
<Image Source="http://www.dynamicdrive.com/dynamicindex4/lightbox2/horses.jpg"
Name="img"/>
<InkCanvas Background="Transparent"
Name="ink"/>
<Button Content="Save"
HorizontalAlignment="Left"
VerticalAlignment="Top"
Margin="5"
Click="SaveImage"/>
</Grid>
</Window>
也许你会找到一种更好的方法来使用这个扩展在 WriteableBitmap 上绘图,我使用的绘图方法只是一个实验。