如何将图像集中在多阶段

Question

找到了将图像定位在多屏幕上的功能...但是我不确定如何获得实际的图像宽度（对于单个或多个），并基于此更改_msi.viewportorigin x param。

有2行影响图像位置...一个是

_msi.ViewportOrigin = new Point(0, 0);

另一个是：

//if (layout == ImageLayout.Vertical) //single column
//    X = ((_msi.ViewportWidth - subImages[i].Width) / 2);

我可以更改任何一个..但需要一些帮助。

从上述摘要中获取的代码：

 private void ArrangeImagesTile(ImageLayout layout)
        {
            if (_msi.ActualWidth <= 0 || _msi.ActualHeight <= 0)
                return;

            _lastMousePos = new Point(0, 0);
            _msi.ViewportOrigin = new Point(0, 0);
            _msi.ViewportWidth = 1;


            Storyboard moveStoryboard = initStoryboard();

            double containerAspectRatio = this._msi.ActualWidth / this._msi.ActualHeight;
            double spaceBetweenImages = 0.005;

            List<SubImage> subImages = new List<SubImage>();
            _imagesToShow.ForEach(subImage => subImages.Add(new SubImage(subImage)));

            // Capture the total width of all images
            double totalImagesWidth = 0.0;
            subImages.ForEach(subImage => totalImagesWidth += subImage.Width);

            // Calculate the total number of rows required to display all the images
            int numRows = 1; // layout - horizontal
            if (layout == ImageLayout.One)
                numRows = 1; //(int)Math.Sqrt((totalImagesWidth / containerAspectRatio) + 1);
            else if (layout == ImageLayout.Four) //.Vertical)
                numRows = 2; // subImages.Count;

            // Assign images to each row
            List<Row> rows = new List<Row>(numRows);
            for (int i = 0; i < numRows; i++)
                rows.Add(new Row(spaceBetweenImages));

            double widthPerRow = totalImagesWidth / numRows;
            double imagesWidth = 0;

            // Separate the images into rows. The total width of all images in a row should not exceed widthPerRow
            for (int i = 0, j = 0; i < numRows; i++, imagesWidth = 0)
            {
                while (imagesWidth < widthPerRow && j < subImages.Count)
                {
                    rows[i].AddImage(subImages[j]);
                    subImages[j].RowNum = i;
                    imagesWidth += subImages[j++].Width;
                }
            }

            // At this point in time the subimage height is 1 
            // If we assume that the total height is also 1 we need to scale the subimages to fit within a total height of 1
            // If the total height is 1, the total width is aspectRatio. Hence (aspectRatio)/(total width of all images in a row) is the scaling factor.
            // Added later: take into account spacing between images
            rows.ForEach(Row => Row.Scale(containerAspectRatio));

            // Calculate the total height, with space between images, of the images across all rows
            // Also adjust the colNum for each image
            double totalImagesHeight = (numRows - 1) * spaceBetweenImages;
            rows.ForEach(Row => totalImagesHeight += Row.Height);

            // The totalImagesHeight should not exceed 1. 
            // if it does, we need to scale all images by a factor of (1 / totalImagesHeight)
            if (totalImagesHeight > 1)
            {
                subImages.ForEach(subImage => subImage.Scale(1 / (totalImagesHeight + spaceBetweenImages)));
                totalImagesHeight = (numRows - 1) * spaceBetweenImages;
                rows.ForEach(Row => totalImagesHeight += Row.Height);
            }

            // Calculate the top and bottom margin
            double margin = (1 - totalImagesHeight) / 2;

            if (_imagesToHide != null)
            {
                // First hide all the images that should not be displayed
                _imagesToHide.ForEach(subImage =>
                {
                    //Do not use opacity for this as it slows down the animation after a few arranges
                    subImage.ViewportWidth = 0;
                });
            }

            // Then display the displayable images to scale
            for (int i = 0; i < _imagesToShow.Count; i++)
            {
                double X = rows[subImages[i].RowNum].CalcX(subImages[i].ColNum);
                //if (layout == ImageLayout.Vertical) //single column
                //    X = ((_msi.ViewportWidth - subImages[i].Width) / 2);

                double Y = margin;
                for (int j = 0; j < subImages[i].RowNum; j++)
                    Y += spaceBetweenImages + rows[j].Height;

                _imagesToShow[i].ViewportWidth = containerAspectRatio / subImages[i].Width;
                animateImage(moveStoryboard, _imagesToShow[i], new Point(-(X / subImages[i].Width), -(Y / subImages[i].Width)));    // for animation, use this statement instead of the next one                
                _imagesToShow[i].Opacity = 1.0;
            }

            if (ImagesRearranged != null)
            {
                ImagesRearranged(this, EventArgs.Empty);
            }

            // Play Storyboard
            moveStoryboard.Begin();
        }

在MSI中打开图像时，该代码参考在上面的函数：

后端：

private void RootMultiScaleImage_Loaded(object sender, RoutedEventArgs e)
        {
            // Use the mid point of the image to zoom from    
            var xx = (MultiScaleImage) sender;
            xx.ZoomAboutLogicalPoint(1, 0.5, 0.5);
        }

前端：

 <ControlTemplate x:Key="DeepZoomerControlTemplate" TargetType="zoom:DeepZoomer">
            <Grid>
<MultiScaleImage x:Name="RootMultiScaleImage" Loaded="RootMultiScaleImage_Loaded" />

Answer 1

我同意这是令人困惑的，但是您应该能够做到这一点。

• 首先，您必须检查viewportwidth是否> 1（这意味着您的图像当前相对于父母而“较窄”。如果不是这种情况，则可以检查viewportotheight> 1（图像较短，您必须中心垂直）。

• 假设您发现视口宽度为> 1，即您在右侧有空的空间，并希望水平居中，则将视图设置为viewportorigin，以将视口移动到右侧。

例子: ：viewportwidth是3。这意味着您的图像填充了可用宽度的1/3。您必须一次将其移至正确的宽度。 viewportorigin变为（-1，0）。

另一个例子: ：viewportwidth是4。您的图像填充了可用宽度的1/4。如果将视口设置为-1.5，则视口实际将其宽度向右移动1.5倍，并实际上移至中心。

通用公式* 应该是fiewportorigin.x = - （viewportwidth -1） / 2

我建议你看看 Doc 并在纸上画一些草图，直到您弄清楚。