参数无效。将数据库中的图像输入图片框 [英] Parameter is not valid. Getting image from database into picture box

问题描述

这是我将图片从picturebox插入数据库的代码。

Image img = this.pictureBox1.Image;

byte [] arr;

ImageConverter converter = new ImageConverter（）;

arr =（byte []）converter.ConvertTo（img，typeof（byte []））;

然后我将arr插入数据库。



这是我用来从数据库中选择图像到图片框的代码。但它给了我一个错误参数无效。



string query =SELECT * FROM Drug WHERE DrugCode ='+ this.DataGridView1.CurrentRow.Cells [0] .Value +';

SqlCommand cmd = new SqlCommand（query，Conet.con）;

SqlDataReader row = cmd.ExecuteReader（）;



Form_EditDrug newMDIChild = new Form_EditDrug（this.txtStaff.Text）;

newMDIChild.TopMost = true;

newMDIChild .BringToFront（）;

if（row.Read（））

{

byte [] data =（byte []）row [ 图片];

MemoryStream ms = new MemoryStream（data）;



newMDIChild.pictureBox1.Image = Image.FromStream（ms）;

}



请帮助。

This is my code for inserting image from picturebox into database.
Image img = this.pictureBox1.Image;
byte[] arr;
ImageConverter converter = new ImageConverter();
arr = (byte[])converter.ConvertTo(img, typeof(byte[]));
I then insert arr into the database.

This is the code I use to select the image from database into a picturebox. But it gives me an error"Parameter is not valid."

string query = "SELECT * FROM Drug WHERE DrugCode = '" + this.DataGridView1.CurrentRow.Cells[0].Value + "'";
SqlCommand cmd = new SqlCommand(query, Conet.con);
SqlDataReader row = cmd.ExecuteReader();

Form_EditDrug newMDIChild = new Form_EditDrug(this.txtStaff.Text);
newMDIChild.TopMost = true;
newMDIChild.BringToFront();
if (row.Read())
{
byte[] data = (byte[])row["Picture"];
MemoryStream ms = new MemoryStream(data);

newMDIChild.pictureBox1.Image = Image.FromStream(ms);
}

Help please.

推荐答案

见这里：为什么我得到参数无效 。我从数据库中读取图像时出现异常？ [ ^ ]



请不要进行数据库访问办法！不要连接字符串以构建SQL命令。它让您对意外或故意的SQL注入攻击持开放态度，这可能会破坏您的整个数据库。请改用参数化查询。

See here: Why do I get a "Parameter is not valid." exception when I read an image from my database?[^]

And please, don't do database access that way! Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead.

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