sql读写图片时Image.FromStream方法提示参数错误问题解决

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我们通常这么写

using (SqlDataReader drm = sqlComm.ExecuteReader()){drm.Read();//以下把数据库中读出的Image流在图片框中显示出来.MemoryStream ms = new MemoryStream((byte[])drm["Logo"]);Image img = Image.FromStream(ms);this.pictureBox1.Image = img;}

 

 

我的写数据

        private void btnOK_Click(object sender, EventArgs e){string name = "";if (tbxUserName.Text.Trim() == ""){MessageBox.Show("姓名不能为空，请重新输入！", "提示");return;}else{name = tbxUserName.Text.Trim();}string group = "";if (cbxGroup.Text.Trim() == ""){group = "未分组";}else{group = cbxGroup.Text.Trim();}string phone = tbxTel.Text.Trim();string workunit = tbxWorkUnit.Text.Trim();string email = tbxEmail.Text.Trim();string qq = tbxQQ.Text.Trim();byte[] b = null;if (txtFilePath != ""){try{FileStream fs = new FileStream(txtFilePath, FileMode.Open, FileAccess.Read);//类型为打开数据 权限为只读 不呢写数据int length = Convert.ToInt32(fs.Length);b = new byte[length];fs.Read(b, 0, length);//数据读入b数组中 从0号到length位fs.Close();//关闭输入输出流}catch (Exception ex){b = null;MessageBox.Show(ex.Message);}}else {b = pixData;}try{using (SqlConnection connection = new SqlConnection(connectionString)){//获取当前的数据在表中的IDSqlCommand commandInsert = new SqlCommand();commandInsert.Connection = connection;//connection.Close();connection.Open();//插入数据commandInsert.CommandText = "USE db_TXL UPDATE tb_BusicInfo set Groups= @Groups ,Name=@Name,WorkUnit=@WorkUnit,Phone=@Phone,Email=@Email,QQ=@QQ,Picture=@Picture";commandInsert.CommandText += "  where ID=@ID ";commandInsert.Parameters.Add("@ID", SqlDbType.Int);commandInsert.Parameters.Add("@Groups", SqlDbType.VarChar, 50);commandInsert.Parameters.Add("@Name", SqlDbType.VarChar, 20);commandInsert.Parameters.Add("@WorkUnit", SqlDbType.VarChar, 50);commandInsert.Parameters.Add("@Phone", SqlDbType.VarChar, 14);commandInsert.Parameters.Add("@Email", SqlDbType.VarChar, 50);commandInsert.Parameters.Add("@QQ", SqlDbType.VarChar, 20);commandInsert.Parameters.Add("@Picture", SqlDbType.Image);//Image的类型不能写错！！commandInsert.Parameters["@ID"].Value = ID;//  commandInsert.Parameters["@UserName"].Value = strUserName;commandInsert.Parameters["@Groups"].Value = group;commandInsert.Parameters["@Name"].Value = name;commandInsert.Parameters["@WorkUnit"].Value = workunit;commandInsert.Parameters["@Phone"].Value = phone;commandInsert.Parameters["@Email"].Value = email;commandInsert.Parameters["@QQ"].Value = qq;//commandInsert.Parameters[""].Value=;if (txtFilePath == "" && pixData==null){commandInsert.Parameters["@Picture"].Value = DBNull.Value;//DBNull  不存在的值NULL}else{commandInsert.Parameters["@Picture"].Value = b;}commandInsert.ExecuteNonQuery();connection.Close();DialogResult = DialogResult.OK;}}catch (Exception ex) { MessageBox.Show(ex.Message); }}

 

我的读数据

     private void frmEdit_Load(object sender, EventArgs e){try{using (SqlConnection connection = new SqlConnection(connectionString)){string commandString = "select * from tb_BusicInfo where ID= " + ID.ToString() + " ";SqlCommand command = new SqlCommand(commandString, connection);connection.Open();SqlDataReader reader = command.ExecuteReader();if (reader.Read()){tbxUserName.Text = Convert.ToString(reader["Name"]);cbxGroup.Text = Convert.ToString(reader["Groups"]);tbxTel.Text = Convert.ToString(reader["Phone"]);tbxWorkUnit.Text = Convert.ToString(reader["WorkUnit"]);tbxEmail.Text = Convert.ToString(reader["Email"]);tbxQQ.Text = Convert.ToString(reader["QQ"]);if (reader["Picture"] == DBNull.Value){pbxPicture.Image = TongXunLu.Properties.Resources.defaultPix;}else{// string a=reader["Picture"].ToString();//  byte[] b = (byte[])((reader["Picture"]));MemoryStream buf = new MemoryStream((byte[])reader["Picture"]);Image image = Image.FromStream(buf);Bitmap bt = new Bitmap(image);pbxPicture.Image = bt;//pbxPicture.Image = image;//  pbxPicture.Image = Image.FromStream(new MemoryStream(b));//把二进制流读出来??问题}}reader.Close();connection.Close();}}catch (Exception ex){MessageBox.Show(ex.Message);}}

 

读数据的时候，但是在写数据的时候可能发生了一些错误。

果然我在追寻byte[]的数组的时候发现 写的时候有2万多个 读的时候只有50个

于是我想可能是写的时候出了问题，于是

 

commandInsert.Parameters.Add("@Picture", SqlDbType.Image,50);

改为commandInsert.Parameters.Add("@Picture", SqlDbType.Image);

照片可以正常显示了

参考了http://blog.csdn.net/zystory/article/details/4399338

你存数据的时候出了问题，和读数据没有关系
new SqlParameter("@L_RolePic", SqlDbType.Image, 16) 改为 new SqlParameter("@L_RolePic", SqlDbType.Image),

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