Question

C#读取二进制图片数据

byte[] bs= new byte[2];
while (reader.Read())
{
bs= (byte[])reader["Image"];
}
MemoryStream ms = new MemoryStream(bs, true);
ms.Write(bs, 0, bs.Length);
pictureBox1.Image = new Bitmap(ms, true);
ms.Dispose();
conn.Close();

为什么我定义byte[？]？任意数字还是能显示图片？里面不是长度吗？不确定二进制图片数据多长，怎么定义？菜鸟呢^-^谢谢！

Answer 1

while (reader.Read())
{
bs = byte[])reader["Image"];
}
这句给bs重新赋值了，bs的地址已经变了，已经不是上面那个new byte[2]了

Answer 2

String sql = "select * from picture where [id]=2";
string str = "server=DA5A491B3F7544B;database=study;uid=sa;pwd=liyi123";
SqlConnection con = new SqlConnection(str);
con.Open();
SqlCommand cmd=new SqlCommand(sql,con);
SqlDataReader sdr = cmd.ExecuteReader();
if(sdr.HasRows)
{
sdr.Read();
byte[] bytes = (byte[]) sdr["pic"];
MemoryStream ms =new MemoryStream(bytes);
Image image = Image.FromStream(ms);
pictureBox1.Image = image;
}
sdr.Close();
con.Close();