我正在将 WPF Visual (UserControl) 渲染到位图,但问题是渲染的图像在缩放/转换之前是 UserControl 的大小。因此,假设 UserControl 设计为 200x200 像素。当我渲染到 BMP 时,我使用 UserControl 的 ActualWidth 和 ActualHeightt,它们分别报告 200 和 200。问题是 UserControl 在 Canvas 中并且自动调整大小(设置为缩放/填充窗口大小)到接近 1200 x 1200(它会改变)
我已经进行了一些阅读和搜索,但到目前为止无法弄清楚如何确定有效大小,即控件在屏幕上绘制的大小。
我遇到了这个听起来很有希望但返回的转换不包含缩放数据的问题。确实如此,但它们都是 1。
Get element position after transform
关于在哪里寻找渲染缩放的任何建议都会很棒!
[更新] 按照建议,我包含了相关代码:
public static Bitmap PngBitmap(this Visual visual)
{
// Get height and width
int width = (int)(double)visual.GetValue(
FrameworkElement.ActualWidthProperty);
int height = (int)(double)visual.GetValue(
FrameworkElement.ActualHeightProperty);
// Render
RenderTargetBitmap rtb =
new RenderTargetBitmap(
width,
height,
96,
96,
PixelFormats.Default);
rtb.Render(visual);
// Encode
PngBitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(rtb));
System.IO.MemoryStream stream = new System.IO.MemoryStream();
encoder.Save(stream);
// Create Bitmap
Bitmap bmp = new Bitmap(stream);
stream.Close();
return bmp;
}
public static BitmapSource BitmapSource(this Visual visual)
{
Bitmap bmp = visual.PngBitmap();
IntPtr hBitmap = bmp.GetHbitmap();
BitmapSizeOptions sizeOptions = BitmapSizeOptions.FromEmptyOptions();
return Imaging.CreateBitmapSourceFromHBitmap(
hBitmap,
IntPtr.Zero,
Int32Rect.Empty,
sizeOptions);
}
[更新 #2] 添加了 XAML - Grid 元素被删除,因为它很大,并且从我对 XAML 的阅读来看,包含键盘 UserControl 的 Canvas 不是 Grid 元素的一部分。
<UserControl xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:PMD.HECAT.DashboardModule"
xmlns:PMD_HECAT_DashboardModule_VirtualKeyboard="clr-namespace:PMD.HECAT.DashboardModule.VirtualKeyboard"
xmlns:System_Windows_Controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Input.Toolkit"
xmlns:PMD_HECAT_DashboardModule_Input="clr-namespace:PMD.HECAT.DashboardModule.Input"
xmlns:control="clr-namespace:PMD.HECAT.DashboardModule.Controls"
x:Class="PMD.HECAT.DashboardModule.CandidateElectrodeView"
x:Name="UserControl"
mc:Ignorable="d"
d:DesignWidth="1024" d:DesignHeight="768" Width="640" Height="360">
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="../Themes/DashboardStyles.xaml" />
<ResourceDictionary Source="../Themes/ImageButtons.xaml" />
<ResourceDictionary Source="CandidateViewResources.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</UserControl.Resources>
<UserControl.Triggers>
<EventTrigger RoutedEvent="PMD_HECAT_DashboardModule_VirtualKeyboard:VirtualKeyboardView.KeyboardClose" SourceName="virtualKeyboardView">
<BeginStoryboard Storyboard="{StaticResource OnKeyboardClose1}"/>
</EventTrigger>
</UserControl.Triggers>
<Canvas Width="100" HorizontalAlignment="Left">
<PMD_HECAT_DashboardModule_VirtualKeyboard:VirtualKeyboardView x:Name="virtualKeyboardView" Height="222" Width="550" RenderTransformOrigin="0.5,0.5" Opacity="0" Active="False">
<PMD_HECAT_DashboardModule_VirtualKeyboard:VirtualKeyboardView.RenderTransform>
<TransformGroup>
<ScaleTransform/>
<SkewTransform/>
<RotateTransform/>
<TranslateTransform X="40" Y="400"/>
</TransformGroup>
</PMD_HECAT_DashboardModule_VirtualKeyboard:VirtualKeyboardView.RenderTransform>
</PMD_HECAT_DashboardModule_VirtualKeyboard:VirtualKeyboardView>
<Rectangle Stroke="White" Opacity="0.7" Fill="White" Height="370" Width="654.851" Canvas.Left="687" Canvas.Top="0" />
</Canvas>
</UserControl>
最佳答案
我知道自从提出这个问题以来已经过去了很多时间,但发布更多信息并没有什么坏处:)
我使用此代码来查找应用了渲染变换的视觉效果的大小(比例)。
GeneralTransform t = transformedVisual.TransformToVisual(parentVisual);
Vector topLeft = (Vector) t.Transform(new Point(0,0));
Vector topRight = (Vector) t.Transform(new Point(originalWidthOfTransformedVisual, 0));
double renderedWidth = (topRight-topLeft).Length;
double widthScale = renderedWidth / originalWidthOfTransformedVisual;
关于wpf - 如何获取 WPF Visual 元素的缩放大小,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/7710483/