当只有一个图钉时，如何确定 Bing 地图的正确缩放级别？

Question

我在地图上添加了一些图钉，然后“调整大小”或“正确缩放”它，以便显示所有图钉，但远边缘的图钉几乎不在边界内，如下所示：

但是，如果只有一个图钉（如以下爱荷华州的情况，它只进行了一场内战），而不是尽可能接近零，它会一直缩小到 Skylab，如下所示：

这是我用来“调整大小”地图的代码：

private void RightsizeZoomLevelForAllPushpins()
{
    try
    {
        // Set the view so that all pushpins are displayed, with a bit of a margin around them
        // from /sf/ask/4604565311/#65781319
        var map = this.userControl11.myMap;
        var locations = map.Children.OfType<Pushpin>().Select(x => x.Location);
        //Margin
        var w = new Pushpin().Width;
        var h = new Pushpin().Height;
        var margin = new Thickness(w / 2, h, w / 2, 0);

        //Set view
        map.SetView(locations, margin, 0);
        currentZoomLevel = Convert.ToInt32(map.ZoomLevel);
        UncheckAllZoomLevelToolstripMenuItems();
        SetZoomMenuItem();
    }
    catch (Exception ex)
    {
        System.Windows.Forms.MessageBox.Show(ex.Message);
    }
}

如何使单图钉地图不仅居中而且尽可能放大？

更新

将括号添加到对 Count 的两个引用，并在 else 块中添加一个“if”以便编译后，我仍然收到以下代码的两个错误：

private void RightsizeZoomLevelForAllPushpins()
{
    try
    {
        // Set the view so that all pushpins are displayed, with a bit of a margin around them
        var map = this.userControl11.myMap;
        var locations = map.Children.OfType<Pushpin>().Select(x => x.Location);

        if (locations.Count() == 1)
        {
            map.setView(locations[0], singlePinZoom);                
        }
        else if (locations.Count() > 1) 
        {
            //Margin
            var w = new Pushpin().Width;
            var h = new Pushpin().Height;
            var margin = new Thickness(w / 2, h, w / 2, 0);

            //Set view
            map.SetView(locations, margin, 0);
        }    
        currentZoomLevel = Convert.ToInt32(map.ZoomLevel);
        UncheckAllZoomLevelToolstripMenuItems();
        SetZoomMenuItem();
    }
    catch (Exception ex)
    {
        System.Windows.Forms.MessageBox.Show(ex.Message);
    }
}

他们是：

1>C:\Users\bclay\source\repos\MyMaps\MyMaps\Form1.cs(155,33,155,45): error CS0021: Cannot apply indexing with [] to an expression of type 'IEnumerable<Location>'
1>C:\Users\bclay\source\repos\MyMaps\MyMaps\Form1.cs(155,25,155,32): error CS1061: 'Map' does not contain a definition for 'setView' and no accessible extension method 'setView' accepting a first argument of type 'Map' could be found (are you missing a using directive or an assembly reference?)

顺便说一句，在我编译项目之前，我在 Visual Studio 中看不到任何错误（它在输入错误时停止发现错误）。我不知道为什么......我没有改变任何设置......

更新 2

这是我现在使用的代码，它不只考虑一个图钉，但确实有效（请注意，“SetView”在此处不会引发异常）：

private void RightsizeZoomLevelForAllPushpins()
    {
        const int LEFT_TOP_RIGHT_MARGIN_ADDITION = 16;
        const int BOTTOM_MARGIN_ADDITION = 48;
        try
        {
            // Set the view so that all pushpins are displayed, with a bit of a margin around them
            // from /sf/ask/4604565311/#65781319
            var map = this.userControl11.myMap;
            var locations = map.Children.OfType<Pushpin>().Select(x => x.Location);
            //Margin
            var w = new Pushpin().Width;
            var h = new Pushpin().Height;
            var margin = new Thickness((w / 2) + LEFT_TOP_RIGHT_MARGIN_ADDITION, 
                                        h + LEFT_TOP_RIGHT_MARGIN_ADDITION, 
                                        (w / 2) + LEFT_TOP_RIGHT_MARGIN_ADDITION, 
                                        0 + BOTTOM_MARGIN_ADDITION);
            //Set view
            map.SetView(locations, margin, 0);
            currentZoomLevel = Convert.ToInt32(map.ZoomLevel);
            UncheckAllZoomLevelToolstripMenuItems();
            SetZoomMenuItem();
        }
        catch (Exception ex)
        {
            System.Windows.Forms.MessageBox.Show(ex.Message);
        }
    }

Answer 1

单个图钉没有单一的缩放级别，最佳缩放级别将取决于您的场景或图钉所代表的内容，以及地图的大小，因为缩放和地图大小都决定了可视区域。例如，如果您的图钉代表一座房屋，您可能希望地图比代表一座城市时放大得更多。

也就是说，这是代码的修改版本，它将处理单引脚场景并使用您选择的静态缩放级别：

private double singlePinZoom = 15;

private void RightsizeZoomLevelForAllPushpins()
{
    try
    {
        // Set the view so that all pushpins are displayed, with a bit of a margin around them
        var map = this.userControl11.myMap;
        var locations = map.Children.OfType<Pushpin>().Select(x => x.Location);

        if(locations.Count() > 0) {
            //Margin
            var w = new Pushpin().Width;
            var h = new Pushpin().Height;
            var margin = new Thickness(w / 2, h, w / 2, 0);

            //Set view
            map.SetView(locations, margin, 0);
        } else(locations.Count == 1) {
            map.setView(locations[0], singlePinZoom);
        }   
        
        currentZoomLevel = Convert.ToInt32(map.ZoomLevel);
        UncheckAllZoomLevelToolstripMenuItems();
        SetZoomMenuItem();
    }
    catch (Exception ex)
    {
        System.Windows.Forms.MessageBox.Show(ex.Message);
    }
}