我正在构建一个 WPF 应用程序,其中需要从视图模型获取窗口的宽度、高度和位置。我正在使用以下 XAML:
<Window x:Class="ScreenCapture.MainWindow"
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"
mc:Ignorable="d"
Height="{Binding Height, Mode=OneWayToSource, FallbackValue=300}"
Width="{Binding Width, Mode=OneWayToSource, FallbackValue=300}"
Title="MVVM Light Application"
Top="{Binding Top, Mode=OneWayToSource}"
Left="{Binding Left, Mode=OneWayToSource}"
DataContext="{Binding Main, Source={StaticResource Locator}}">
<Window.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Skins/MainSkin.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Window.Resources>
<Grid x:Name="LayoutRoot">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="13*" />
<ColumnDefinition Width="265*" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition Height="25" />
</Grid.RowDefinitions>
<TextBlock FontSize="36"
FontWeight="Bold"
Foreground="Purple"
Text="{Binding Welcome}"
VerticalAlignment="Center"
HorizontalAlignment="Center"
TextWrapping="Wrap" Grid.Column="1" Margin="19,70,32,70" />
<Button Grid.Row="1" Content="Capture" Grid.ColumnSpan="2" Command="{Binding Capture}" />
</Grid>
</Window>
在我的视图模型中,Top、Left 的值工作正常,但是 Width 和 Height 属性均为 NaN。对于我绑定的每个属性,我都有这样的属性:
private double height;
public double Height
{
set
{
height = value;
}
}
知道为什么这些值会返回 NaN 吗?更重要的是,我可以做什么来获得我正在寻找的价值观?
EDIT:我意识到这有点不对劲,但我需要从视图模型捕获应用程序的屏幕截图。视图模型包含我没有粘贴的其他属性,但它们是实现所需功能所必需的。出于好奇,以下是我捕获屏幕的方法:
private void CaptureScreen()
{
int x = Convert.ToInt32(left);
int y = Convert.ToInt32(top);
int w = Convert.ToInt32(width);
int h = Convert.ToInt32(height);
Bitmap image = new Bitmap(w, h);
Graphics graphics = Graphics.FromImage(image);
graphics.CopyFromScreen(x, y, x, y, new Size(w, h), CopyPixelOperation.SourceCopy);
// Do something with the image
}