更新图片datagrid C# [英] Update picture datagrid C#
本文介绍了更新图片datagrid C#的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
Insert picture working fine, I have problem with update...some help?
错误是(更新时)
Error is(when update)
Object reference not set to an instance of an object
我尝试过的:
What I have tried:
string fileName;
private void buttonupload_Click(object sender, EventArgs e)
{
//Read image file
using (OpenFileDialog ofd = new OpenFileDialog() { Filter = "JPEG|*.jpg|BMP|*.bmp|PNG|*.png|All Files|*.*", ValidateNames = true, Multiselect = false })
{
if (ofd.ShowDialog() == DialogResult.OK)
{
fileName = ofd.FileName;
pictureBox1.Image = System.Drawing.Image.FromFile(fileName);
}
}
}
private void buttonsave_Click(object sender, EventArgs e)
{
byte[] img_arr = null;
MemoryStream ms = new MemoryStream();
pictureBox1.Image.Save(ms, pictureBox1.Image.RawFormat);
img_arr = ms.GetBuffer();
using (SqlConnection openCon = new SqlConnection(cs))
{
string saveStaff = "INSERT INTO dbo.radnici ( data) VALUES (@data)";
using (SqlCommand querySaveStaff = new SqlCommand(saveStaff))
{
querySaveStaff.Connection = openCon;
querySaveStaff.Parameters.AddWithValue("@data", img_arr);
openCon.Open();
querySaveStaff.ExecuteNonQuery();
openCon.Close();
}
}
else
{
using (SqlConnection openCon = new SqlConnection(cs))
{
string updateStaff = "UPDATE dbo.radnici SET data=@data WHERE id= " + idTextBox.Text;
using (SqlCommand querySaveStaff = new SqlCommand(saveStaff))
{
queryupdateStaff.Connection = openCon;
queryupdateStaff.Parameters.AddWithValue("@data", img_arr);
openCon.Open();
queryupdateStaff.ExecuteNonQuery();
MessageBox.Show("Uspješno ste izmenili stavku!", "Informacija", MessageBoxButtons.OK, MessageBoxIcon.Information);
openCon.Close();
}
}
}
推荐答案
using (SqlCommand querySaveStaff = new SqlCommand(saveStaff))
此行我应该使用
this line i this you should use
updateStaff
更新时
inserted of
saveStaff
更新时的查询参数
in query parameter while updating
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