将文本坐标放在C＃图形位图的位置

Question

我编写了一个C＃Render方法，将热图呈现到Grasshopper画布上。 Grasshopper是一个Rhino插件，允许一个简单的GUI编程接口。

protected override void Render(Grasshopper.GUI.Canvas.GH_Canvas canvas, Graphics graphics, Grasshopper.GUI.Canvas.GH_CanvasChannel channel) {

            base.Render(canvas, graphics, channel);

            if (channel == Grasshopper.GUI.Canvas.GH_CanvasChannel.Wires) {
                var comp = Owner as KT_HeatmapComponent;
                if (comp == null)
                    return;

                List<HeatMap> maps = comp.CachedHeatmaps;
                if (maps == null)
                    return;

                if (maps.Count == 0)
                    return;

                int x = Convert.ToInt32(Bounds.X + Bounds.Width / 2);
                int y = Convert.ToInt32(Bounds.Bottom + 10);

                for (int i = 0; i < maps.Count; i++) {
                    Bitmap image = maps[i].Image;
                    if (image == null)
                        continue;

                    Rectangle mapBounds = new Rectangle(x, y, maps[i].Width, maps[i].Height);
                    //Rectangle mapBounds = new Rectangle(x, y, maps[i].Width * 10, maps[i].Height * 10);
                    mapBounds.X -= mapBounds.Width / 2;

                    Rectangle edgeBounds = mapBounds;
                    edgeBounds.Inflate(4, 4);

                    GH_Capsule capsule = GH_Capsule.CreateCapsule(edgeBounds, GH_Palette.Normal);
                    capsule.Render(graphics, Selected, false, false);
                    capsule.Dispose();

                    graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.NearestNeighbor;
                    graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.Half;
                    graphics.DrawImage(image, mapBounds);
                    graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                    graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.Default;
                    graphics.DrawRectangle(Pens.Black, mapBounds);

                    y = edgeBounds.Bottom - (mapBounds.Height) - 4;
                }
            }
        }

目前，此渲染方法将这样的图像绘制到画布上：

话虽如此，我想在顶部放置一些标题文本，并为X和Y轴添加标签，就像标准热图图一样。但是，我对graphics组件的理解太有限了，我想请求你们帮助。

我做了一些研究，似乎drawText()方法可以做我想做的事：c# write text on bitmap

但我不确定在何处指定坐标，同时在显示的图形顶部留下一些空格来放置标题文本。

Answer 1

GDI +使用的坐标系从顶角开始，是（0,0） 右下角（fullimagewidth，fullimageheight）

所以如果你需要在图像的topleft角上画画，请使用

//Position
PointF drawPoint = new PointF(0F, 0F);
// Draw string to screen.
e.Graphics.DrawString("hey", drawFont, drawBrush, drawPoint);