一、保持图片比例跟随控件大小缩放
pictureBox1.SizeMode = PictureBoxSizeMode.Zoom;//PictureBoxSizeMode.StretchImage; pictureBox1.BackgroundImageLayout = ImageLayout.Zoom;//ImageLayout.Stretch;
pictureBox1.SizeMode = PictureBoxSizeMode.Zoom;//PictureBoxSizeMode.StretchImage; pictureBox1.BackgroundImageLayout = ImageLayout.Zoom;//ImageLayout.Stretch;