如何用C＃中的参数编写这段代码？

问题描述

这是我在c＃中的更新代码：

this is my update code in c# :

private void BtnٍEdit_Click(object sender, EventArgs e)
       {
           string sqlcon = "Data Source=desktop-nee5996\\shadow;Initial Catalog=Filelib;Integrated Security=True";
           SqlConnection cn = new SqlConnection(sqlcon);
           try
           {


               if (TxtName.Text == "")
               {
                   MessageBox.Show("Please Inset Name.", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
               }
               else
               {
                   cn.Open();

                   SqlStr = "update Filelib set  ";
                   SqlStr = SqlStr + " Name='" + TxtName.Text.Trim() + "',";
                   SqlStr = SqlStr + " Year='" + TxtYear.Text.Trim() + "',";
                   SqlStr = SqlStr + " Director='" + TxtDirector.Text.Trim() + "',";
                   SqlStr = SqlStr + " Quality='" + TxtQuality.Text.Trim() + "',";
                   SqlStr = SqlStr + " Size='" + TxtSize.Text.Trim() + "'";
                   SqlStr = SqlStr + " where Id_Files='" + TxtId_Files.Text + "'";
                   sqlcmd = new SqlCommand(SqlStr, cn);
                   sqlcmd.ExecuteNonQuery();
                   MessageBox.Show("Edited succesefully.", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);

                   Filelibindex FrmTxtId_Files = new Filelibindex();
                   this.Hide();
                   FrmTxtId_Files.ShowDialog();
               }
           }
           finally
           {
               cn.Close();
           }
       }

这是我的填充网格视图代码：

and this is my code for fill grid view :

public void fillGrid()
        {
            String sqlcon = "Data Source=desktop-nee5996\\shadow;Initial Catalog=Filelib;Integrated Security=True";
            SqlConnection cn = new SqlConnection(sqlcon);

            try
            {

                cn.Open();
                SqlStr = "Select IdAttachBord,";
                SqlStr = SqlStr + " FkIdFiles,";
                SqlStr = SqlStr + " FilePath,";
                SqlStr = SqlStr + " FileData,";
                SqlStr = SqlStr + " FileName,";
                SqlStr = SqlStr + " SafeFileName";
                SqlStr = SqlStr + " from FilelibF";
                SqlStr = SqlStr + " where FkIdFiles ='" + IdFileStudent.Text + "'";
                SqlDataAdapter ADAP = new SqlDataAdapter(SqlStr, cn);
                pagingAdapter = new SqlDataAdapter(SqlStr, cn);
                pagingDS = new DataSet();
                DS = new DataSet();
                ADAP.Fill(DS, "FilelibF");
                pagingAdapter.Fill(pagingDS, scrollVal, 7, "paging");
                GridFile.DataSource = DS.Tables["FilelibF"];
                GridFile.DataSource = pagingDS;
                GridFile.DataMember = "paging";
                GridFile.Columns[4].HeaderText = "File Name";
                GridFile.Columns[0].Visible = false;
                GridFile.Columns[1].Visible = false;
                GridFile.Columns[2].Visible = false;
                GridFile.Columns[3].Visible = false;
                GridFile.Columns[5].Visible = false;



            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }



        }

i认为此代码有一些错误请告诉我如何修复错误以及如何用C＃中的参数编写这两个代码？谢谢你。

i think this code have some mistakes please tell me how to fix mistakes and how to write these two codes with parameters in C# ? thank you.

推荐答案

SqlStr = "UPDATE Filelib SET Name='" + TxtName.Text.Trim() + "' WHERE Id_Files='" + TxtId_Files.Text + "'";
sqlcmd = new SqlCommand(SqlStr, cn);
sqlcmd.ExecuteNonQuery();

然后将其转换为：

Then just convert it to:

SqlStr = "UPDATE Filelib SET Name=@NM WHERE Id_Files=@ID";
sqlcmd = new SqlCommand(SqlStr, cn);
sqlcmd.Parameters.AddWithValue("@NM", TxtName.Text.Trim());
sqlcmd.Parameters.AddWithValue("@ID", TxtId_Files);
sqlcmd.ExecuteNonQuery();

按照你的整个代码的模式，你会没事的。

Follow that pattern for your whole code, and you'll be fine.

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