获取 WPF ImageControl 中显示图像的大小

Question

我在 WPF 的图像控件中有一个图像。

如何获取imageControl中图片的高宽转换为IN后的显示大小？

Answer 1

Size displayedImageSize = new Size((int)imageControl.ActualWidth, (int)imageControl.ActualHeight);

Answer 2

我测试了Tam Bui解决方案，当图像尺寸小于图像控件尺寸时它不能正常工作。

我的解决方案：

先用ImageSourceToMemoryStream（我的方法）把Image.Source转成MemoryStream，再转成BitmapImage，最后得到[=16的高和宽=].

输出（在 Visual Studio 2017 中测试，.Net Framework 4.5.2）：

我在 png 和高清 jpg 图像上测试了它。

PNG:

高清 JPG：

注意：如果此解决方案对您有帮助，请标记为答案（别忘了给我投票）。

XAML:

    <Image x:Name="ImageControl" HorizontalAlignment="Left" Height="113" Margin="56,42,0,0" VerticalAlignment="Top" Width="159"/>
    <Button x:Name="ChooseImage" Content="Choose image" Click="ChooseImage_Click" HorizontalAlignment="Left" Height="25" Margin="392,276,0,0" VerticalAlignment="Top" Width="90"/>
    <Button x:Name="CalculateImageSize" Content="Calculate image size" Click="CalculateImageSize_Click" HorizontalAlignment="Left" Height="25" Margin="257,276,0,0" VerticalAlignment="Top" Width="120"/>

C#:

注意：BitmapEncoder必须设置为GifBitmapEncoder才能计算高清图片的尺寸（或更高），否则不会return得到正确的结果。

    int Height = 0;
    int Width = 0;
    public System.IO.MemoryStream ImageSourceToMemoryStream(BitmapEncoder BitEncoder, ImageSource ImgSource)
    {
        System.IO.MemoryStream Stream = null;
        switch ((ImgSource as BitmapSource) != null)
        {
            case true:
                BitEncoder.Frames.Add(BitmapFrame.Create((ImgSource as BitmapSource)));
                Stream = new System.IO.MemoryStream();
                BitEncoder.Save(Stream);
                break;
        }
        return Stream;
    }
    private void ChooseImage_Click(object sender, RoutedEventArgs e)
    {
        System.Windows.Forms.OpenFileDialog OP = new System.Windows.Forms.OpenFileDialog();
        OP.Filter= "All files (*.*)|*.*|JPG (*.jpg)|*.jpg|BMP (*.bmp)|*.bmp|GIF (*.gif)|*.gif|PNG (*.png)|*.png";
        OP.AutoUpgradeEnabled = false;
        if (OP.ShowDialog() == System.Windows.Forms.DialogResult.OK)
        {
            var IMG = System.Drawing.Image.FromFile(OP.FileName);
            BitmapImage BitMapImage = new BitmapImage();
            BitMapImage.BeginInit();
            System.IO.MemoryStream MemoryStream = new System.IO.MemoryStream();
            IMG.Save(MemoryStream, System.Drawing.Imaging.ImageFormat.Png);
            MemoryStream.Seek(0, System.IO.SeekOrigin.Begin);
            BitMapImage.StreamSource = MemoryStream;
            BitMapImage.EndInit();
            ImageControl.Source = BitMapImage;
        }
    }
    private void CalculateImageSize_Click(object sender, RoutedEventArgs e)
    {
        BitmapImage BitMapImage = new BitmapImage();
        BitMapImage.BeginInit();
        //BitmapEncoder must be set to GifBitmapEncoder to calculate the size of HD images (or higher), otherwise it will not return the correct result
        var MemoryStream = ImageSourceToMemoryStream(new GifBitmapEncoder(), ImageControl.Source);
        MemoryStream.Seek(0, System.IO.SeekOrigin.Begin);
        BitMapImage.StreamSource = MemoryStream;
        BitMapImage.EndInit();
        Height = (int)BitMapImage.Height;
        Width = (int)BitMapImage.Width;
        ImageControl.Source = BitMapImage;
        Size DisplayedImageSize = new Size(Width, Height);
        MessageBox.Show("Image control width = " + ImageControl.Width.ToString() + ", Image width = " + Width.ToString() + ", Image control height = " + ImageControl.Height.ToString() + ", Image height = " + Height.ToString());
    }

谢谢

获取 WPF ImageControl 中显示图像的大小

Get the size of a displayed image inside a WPF ImageControl

c#

wpf

image

display