从数据库读取图片为什么只能显示System.Byte[]??

Question

从数据库里读图片出来只能显示System.Byte[]??
代码
string ImgID = Request.QueryString["Portfolio_ID"];
        SqlConnection MyConnection = new SqlConnection("Server=.;Uid=sa;Pwd=;DataBase=Portfolio_System");
        SqlCommand MyCmd = new SqlCommand("Select * From Portfolio Where Portfolio_ID='"+ImgID+"'",MyConnection);
        MyConnection.Open();
        SqlDataReader ODR = MyCmd.ExecuteReader();
        if (ODR.Read())
        {
            Response.ContentType = ODR["ImgType"].ToString();
            Response.BinaryWrite((Byte[])ODR["Img"]);
        }
        MyConnection.Close();
    }

Answer 1

不太清楚，记得以前写时byte是小写的啊

Answer 2

DataSet ds=new DataSet();
ds = dbs.table_Select(sql);
Response.ContentType = "image/jpeg";
Response.BinaryWrite((byte[])ds.Tables[0].Rows[0][0]);我以前这么些可以的。试试阿

Answer 3

private void Button1_Click(object sender, System.EventArgs e)
{
System.Web.HttpPostedFile upfile=this.File1.PostedFile;
int length=upfile.ContentLength;
try
{
if(length==0)
{
this.Label1.Text="请选择您上传的文件";
}
else
{
byte[] fileByteArr=new byte[length];
Stream streamObject =upfile.InputStream;
streamObject.Read(fileByteArr,0,length);
string strCon="server=localhost;uid=sa;password=123;database=northwind";
SqlConnection cn= new  SqlConnection(strCon);
string sql="insert into images(data,contenttype,description,imagesize) values(@data,'{0}','{1}','{2}')";
string sqlInsert=string.Format(sql,upfile.ContentType,this.TextBox1.Text.ToString(),length);

SqlCommand cmd=new SqlCommand(sqlInsert,cn);
cmd.Parameters.Add("@data",System.Data.SqlDbType.Image);
cmd.Parameters["@data"].Value=fileByteArr;
cmd.Connection.Open();
cmd.ExecuteNonQuery();
cmd.Connection.Close();
this.Label1.Text="上传成功";
}
}
catch(Exception ex)
{
this.Label1.Text=ex.Message.ToString(); }
} private void Button2_Click(object sender, System.EventArgs e)
{
string strCon="server=localhost;uid=sa;password=123;database=northwind";
SqlConnection cn= new  SqlConnection(strCon);
string sql="select * from images where id=4";
SqlCommand cmd=new SqlCommand(sql,cn);
cmd.Connection.Open();
SqlDataReader dr=cmd.ExecuteReader();
if(dr.Read())
{
Response.ContentType=dr["contenttype"].ToString();
Response.OutputStream.Write((byte[])dr["data"],0,(int)dr["imagesize"]);
}
dr.Close();
cmd.Connection.Close();

}这是完整的上传图片到sql和显示图片的例子
Response.OutputStream.Write((byte[])dr["data"],0,(int)dr["imagesize"]);
输出要这么写吧

Answer 4

我用的是Access数据库,存放图片用的是Ole对象..
用你的方法,读取的时候提示指定的转换无效...
行:Response.OutputStream.Write((byte[])ODR["ImageData"],0,(int)ODR["Image_Size"]);

Answer 5

晕了...换成Sql Server的也是一样,难道2.0和1.1不同???

Answer 6

string str=System.Configuration.ConfigurationSettings.AppSettings["cn"];
SqlConnection cn=new SqlConnection(str);
SqlCommand cmd=new SqlCommand();
cmd.CommandText="select Cover from Books where BookGuid='"+this.Request["ImageID"]+"'";
cmd.Connection=cn;
cn.Open();
this.Response.ContentType="image/*";
SqlDataReader dr=cmd.ExecuteReader();
while(dr.Read())
{
this.Response.BinaryWrite((byte[])dr["Cover"]);
}
cn.Close();