c# 实现图像180度旋转

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace WindowsFormsApplication1

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        Bitmap bitmap1;

        private void InitializeBitmap()

        {

            try

            {

                bitmap1 = (Bitmap)Properties.Resources.a;

                pictureBox1.SizeMode = PictureBoxSizeMode.AutoSize;

                pictureBox1.Image = bitmap1;

            }

            catch (System.IO.FileNotFoundException)

            {

                MessageBox.Show("There was an error." +

                    "Check the path to the bitmap.");

            }

        }

        private void button1_Click(System.Object sender, System.EventArgs e)

        {

            if (bitmap1 != null)

            {

                bitmap1.RotateFlip(RotateFlipType.Rotate180FlipY);

                pictureBox1.Image = bitmap1;

            }

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            InitializeBitmap();

        }

    }

}