读SQL里二进制图片时Bitmap的参数无效

[caowenkai]

protected void btnSave_Click(object sender, EventArgs e)
{
int ProdID;
ProdID = int.Parse(txtProdID.Text);
//保存图片
this.SaveImageToDB(ProdID);
Response.Write("图片保存成功！");
}
/// <summary>
/// 保存图片入库
/// </summary>
/// <param name="ProdID"></param>
private void SaveImageToDB(int ProdID)
{
string imgName = string.Empty;
string imgContentType = string.Empty;
int imgLen;
byte[] imgbin;
string imgName2 = string.Empty;
string imgContentType2 = string.Empty;
byte[] imgbin2;
//检查文件是否存在
if (fUpLoadImage.PostedFile != null)
{
if (fUpLoadImage.PostedFile.FileName.Trim().Length > 0 && fUpLoadImage.PostedFile.ContentLength > 0)
{
Stream imgStream = fUpLoadImage.PostedFile.InputStream;//此位置imgStream出现异常报此流不支持超时，但是图片还是存到数据库，运行也正常。我跟踪的时候发现的。
imgLen = fUpLoadImage.PostedFile.ContentLength;
imgContentType = fUpLoadImage.PostedFile.ContentType;
imgName=fUpLoadImage.PostedFile.FileName.Substring(fUpLoadImage.PostedFile.FileName.LastIndexOf("\\") + 1);
byte[] imgBinaryData = new byte[imgLen];
int n = imgStream.Read(imgBinaryData, 0, imgLen);
imgbin = imgBinaryData;

//保存缩略图

imgName2 = "Thumb_" + imgName;
imgContentType2 = imgContentType;
imgbin2 = createThumnail(imgStream, 145, 145);

//保存图片到数据库

SqlConnection conn = new SqlConnection();
conn.ConnectionString = connstr;
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = "insert_Product_image";

SqlParameter p1 = new SqlParameter("@ProdID", SqlDbType.Int);
SqlParameter p2 = new SqlParameter("@img_name", SqlDbType.VarChar, 50);
SqlParameter p3 = new SqlParameter("@img_data", SqlDbType.Image);
SqlParameter p4 = new SqlParameter("@img_contenttype", SqlDbType.VarChar, 50);
SqlParameter p5 = new SqlParameter("@img_name2", SqlDbType.VarChar, 50);
SqlParameter p6 = new SqlParameter("@img_data2", SqlDbType.Image);
SqlParameter p7 = new SqlParameter("@img_contenttype2", SqlDbType.VarChar, 50);

p1.Value = ProdID;
p2.Value = imgName;
p3.Value = imgbin;
p4.Value = imgContentType;
p5.Value = imgName2;
p6.Value = imgbin2;
p7.Value = imgContentType2;

cmd.Parameters.Add(p1);
cmd.Parameters.Add(p2);
cmd.Parameters.Add(p3);
cmd.Parameters.Add(p4);
cmd.Parameters.Add(p5);
cmd.Parameters.Add(p6);
cmd.Parameters.Add(p7);

conn.Open();
cmd.ExecuteNonQuery();
conn.Close();

}
}
}
以上为存图片的代码，以下代码为读图片：ShowImage.aspx
if (!IsPostBack)
{
this.GetPhoto(1, 400);
}
/// <summary>
/// 经过处理获取所略图
/// </summary>
/// <param name="ms"></param>
/// <param name="height"></param>
/// <returns></returns>
private byte[] LessonPicAutoWidth(MemoryStream ms, int height)
{
byte[] ChagedByte;
System.Drawing.Image OriginalImage = System.Drawing.Image.FromStream(ms, true);
System.Drawing.Bitmap OriginalPic, NewPic;
OriginalPic = new System.Drawing.Bitmap(OriginalImage);

int Width = height * OriginalPic.Width / OriginalPic.Height;

if (Width > 280)
{
Width = 280;
}

NewPic = new Bitmap(OriginalPic, Width, height);
MemoryStream Newms = new MemoryStream();
NewPic.Save(Newms, System.Drawing.Imaging.ImageFormat.Jpeg);
ChagedByte = Newms.GetBuffer();
OriginalPic.Dispose();
NewPic.Dispose();
Newms.Close();

return ChagedByte;
}
/// <summary>
/// 显示图片
/// </summary>
/// <param name="EmployeeID"></param>
public void GetPhoto(int ProdID, int height)
{
Response.Expires = -9999;
Response.AddHeader("pragma", "no-cache");
Response.AddHeader("cache-ctrol", "no-cache");
Response.ContentType = "image/jpeg";
Bitmap bmp;
byte[] PhotoByte;
string sql = string.Format("Select img_data From insert_Product_image Where ProdID={0}", ProdID);

using (SqlConnection conn = new SqlConnection(connstr))
{
using (SqlCommand cmd = conn.CreateCommand())
{
conn.Open();
cmd.CommandText = sql;
using (SqlDataReader reader = cmd.ExecuteReader(CommandBehavior.SequentialAccess))
{
reader.Read();
PhotoByte = (byte[])(reader.GetValue(0));
}
}
}
if (PhotoByte == null || PhotoByte.Length == 0) return;

MemoryStream tempStream = new MemoryStream(PhotoByte);//此位置的tempStream 也出现异常报此流不支持超时，也是我跟踪的时候发现的。
bmp = new Bitmap(tempStream);//这里就出错了，报tempStream参数无效。程序终止。

Response.ContentType = "image/jpeg";
bmp.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
Response.End();
}

[caowenkai]

没一个人会吗？会的帮帮忙，谢谢.很急！

[greystar]

tempStream.Position=0;

[houlinghouling]

图片保存到数据库的方法：

public void imgToDB(string sql)
{ //参数sql中要求保存的imge变量名称为@images
//调用方法如：imgToDB("update UserPhoto set Photo=@images where UserNo='" + temp + "'");
FileStream fs = File.OpenRead(t_photo.Text);
byte[] imageb = new byte[fs.Length];
fs.Read(imageb, 0, imageb.Length);
fs.Close();
SqlCommand com3 = new SqlCommand (sql,con);
com3.Parameters.Add("@images", SqlDbType.Image).Value = imageb;
if (com3.Connection.State == ConnectionState.Closed)
com3.Connection.Open();
try
{
com3.ExecuteNonQuery();
}
catch
{ }
finally
{ com3.Connection.Close(); }
}

数据库中读出图片并显示在picturebox中：

方法一：
private void ShowImage(string sql)
{
//调用方法如：ShowImage("select Photo from UserPhoto where UserNo='" + userno +"'");
SqlCommand cmd = new SqlCommand(sql, conn);
conn.Open();
byte[] b= (byte[])cmd.ExecuteScalar();
if (b.Length 〉 0)
{
MemoryStream stream = new MemoryStream(b, true);
stream.Write(b, 0, b.Length);
pictureBox1.Image = new Bitmap(stream);
stream.Close();
}
conn.Close();
}

方法二：当在dg中选中某行时：
private void dg_MouseUp(object sender, MouseEventArgs e)
{
//整行选择
if (e.Button == System.Windows.Forms.MouseButtons.Left)
{//用户编号，姓名，性别，身份证号，籍贯，学院，系所，校区，部门，电话，照片
//显示相片
object imgobj=dg[10, dg.CurrentRow.Index].Value;
if (imgobj != null && !Convert.IsDBNull(imgobj))
{
byte[] imgb = (byte[])imgobj;
MemoryStream memStream = new MemoryStream(imgb);
try
{
Bitmap myimge = new Bitmap(memStream);
this.pictureBox1.Image = myimge;
}
catch
{
DB.msgbox("从数据库读取相片失败！");
}
}
else
pictureBox1.Image = null;
}
}

[greystar]

MemoryStream tempStream = new MemoryStream(PhotoByte);//此位置的tempStream 也出现异常报此流不支持超时，也是我跟踪的时候发现的。

tempStream.Position=0;


bmp = new Bitmap(tempStream);//这里就出错了，报tempStream参数无效。程序终止。

[mjjzg]

路过，捧个场，顶一下

[caowenkai]

我这样写了不行啊

MemoryStream tempStream = new MemoryStream(PhotoByte);
tempStream.Position = 0;

bmp = new Bitmap(tempStream);

[caowenkai]

同样还是报参数无效

MemoryStream tempStream = new MemoryStream(PhotoByte);
tempStream.Position = 0;

bmp = new Bitmap(tempStream);

[huwenting]

帮忙顶下.此贴不要沉，我也有这个问题！

[caowenkai]

来几个会的帮帮忙啊！

[caowenkai]

难道一个CSDN没有一个会 数据库图片存和读的?

[冷月孤峰]

baidu一下很多
http://www.cnblogs.com/nacarat/articles/912138.html

[wh469696366]

有人有好的解决办法吗？？

[heshl]

我也是同样问题，参数无效的原因就是MemoryStream不支持超时，我想可能得重写下MemoryStream.

[fanshengrui]

我估计你的软件错误，我也经历了，不过你可以去下一个单机的一种开发语言环境去按照上面的方法就可以了！

[晓景]

数据库在读出时文件被破坏了。