关于pictureBox绑定图像，并保存图像到数据库进行读写

浏览：

string fileName = string.Empty; 

private void button1_Click(object sender, EventArgs e)
{
OpenFileDialog openFileDialog1 = new OpenFileDialog();
openFileDialog1.Filter = "*.BMP,*.JPG;*.GIF|*.BMP;*.JPG;*.GIF";
openFileDialog1.ShowDialog();
fileName = openFileDialog1.FileName;
Image a = Image.FromFile(openFileDialog1.FileName);

Bitmap bit = new Bitmap(pictureBox1.Width, pictureBox1.Height);
Graphics g = Graphics.FromImage(bit);//从指定的 Image 创建新的 Graphics(绘图)。
g.DrawImage(a, new Rectangle(0, 0, bit.Width, bit.Height), new Rectangle(0, 0, a.Width, a.Height), GraphicsUnit.Pixel);
//第一个参数：要绘制的图像
//第二个参数：它指定所绘制图像的位置和大小。 将图像进行缩放以适合该矩形。
//第三个参数：它指定 image 对象中要绘制的部分。
pictureBox1.Image = bit;
}
确定：上传到数据库
private void button2_Click(object sender, EventArgs e)
{
FileStream fs = File.OpenRead(fileName);
byte[] img = new byte[fs.Length];
fs.Read(img, 0,img.Length);
fs.Close();
SqlConnection conn = new SqlConnection(ConfigurationSettings.AppSettings["Conn"].ToString());
SqlParameter p = new SqlParameter("@images", img);
SqlCommand sc = new SqlCommand("update Employees set employeeTx = @images where employeeID =2",conn);
sc.Parameters.Add(p);
if (sc.Connection.State == ConnectionState.Closed)
{
sc.Connection.Open();
}

sc.ExecuteNonQuery();
sc.Connection.Close();
Form3 f = new Form3();
this.Hide();
f.Show();

}

Form3窗体中显示图像 ：

private void Form3_Load(object sender, EventArgs e)
{
SqlConnection conn = new SqlConnection(ConfigurationSettings.AppSettings["Conn"]);
SqlCommand com = new SqlCommand("select employeeTx from Employees where employeeID = 2",conn);
conn.Open();
byte[] b = (byte[])com.ExecuteScalar();
if (b.Length > 0)
{
MemoryStream s = new MemoryStream(b, true);
s.Write(b,0,b.Length);

Image a = new Bitmap(s);

Bitmap bit = new Bitmap(pictureBox1.Width, pictureBox1.Height);
Graphics g = Graphics.FromImage(bit);//从指定的 Image 创建新的 Graphics(绘图)。
g.DrawImage(a, new Rectangle(0, 0, bit.Width, bit.Height), new Rectangle(0, 0, a.Width, a.Height), GraphicsUnit.Pixel);
//第一个参数：要绘制的图像
//第二个参数：它指定所绘制图像的位置和大小。 将图像进行缩放以适合该矩形。
//第三个参数：它指定 image 对象中要绘制的部分。
pictureBox1.Image = bit;
}
} 

另：绘制边框

private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
  e.Graphics.DrawRectangle(new Pen(Color.Black, 2), new Rectangle(new Point(1, 1), new Size(this.pictureBox1.Width - 2, this.pictureBox1.Height - 2))); //考虑到线的宽度为4
}