Question

这是导致错误的代码：

void FillGridView()
{
    if (sqlCon.State == ConnectionState.Closed)
        sqlCon.Open();

    SqlDataAdapter sqlDa = new SqlDataAdapter(sqlCon);
    sqlDa.SelectCommand.CommandType = CommandType.StoredProcedure;

    DataTable dtbl = new DataTable();
    sqlDa.Fill(dtbl);

    sqlCon.Close();

    gvContact.DataSource = dtbl;
    gvContact.DataBind();
}

这是连接数据库的全部代码。我从数据库的属性中获取了连接字符串。

public partial class Contact : System.Web.UI.Page
{
    SqlConnection sqlCon = new SqlConnection(@"Data Source=ANILRANA-TOSH;Initial Catalog=cruddb;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False");

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            btnDelete.Enabled = false;
            FillGridView();
        }
    }

    protected void btnClear_Click(object sender, EventArgs e)
    {
        Clear();
    }

    public void Clear()
    {
        hfContactID.Value = "";
        txtName.Text = txtMobile.Text = txtAddress.Text = "";
        lblSuccessMessage.Text = lblErrorMessage.Text = "";
        btnSave.Text = "Save";
        btnDelete.Enabled = false;
    }

    protected void btnSave_Click(object sender, EventArgs e)
    {
        if (sqlCon.State == ConnectionState.Closed)
            sqlCon.Open();

        SqlCommand sqlCmd = new SqlCommand("ContactCreateOrUpdate", sqlCon);
        sqlCmd.CommandType = CommandType.StoredProcedure;
        sqlCmd.Parameters.AddWithValue("@ContactID", (hfContactID.Value==""?0:Convert.ToInt32(hfContactID.Value)));
        sqlCmd.Parameters.AddWithValue("@Name", txtName.Text.Trim());
        sqlCmd.Parameters.AddWithValue("@Mobile",txtMobile.Text.Trim());
        sqlCmd.Parameters.AddWithValue("@Address", txtAddress.Text.Trim());

        sqlCmd.ExecuteNonQuery();

        sqlCon.Close();
        FillGridView();
        string ContactID = hfContactID.Value;
        Clear();

        if (hfContactID.Value == "")
            lblSuccessMessage.Text = "Saved Successfully";
        else
            lblSuccessMessage.Text = "Updated Successfully";
    }

    void FillGridView()
    {
        if (sqlCon.State == ConnectionState.Closed)
            sqlCon.Open();

        SqlDataAdapter sqlDa = new SqlDataAdapter(sqlCon);
        sqlDa.SelectCommand.CommandType = CommandType.StoredProcedure;

        DataTable dtbl = new DataTable();
        sqlDa.Fill(dtbl);

        sqlCon.Close();

        gvContact.DataSource = dtbl;
        gvContact.DataBind();
    }

    protected void lnk_OnClick(object sender, EventArgs e)
    {
        int ContactID = Convert.ToInt32((sender as LinkButton).CommandArgument);

        if (sqlCon.State == ConnectionState.Closed)
            sqlCon.Open();

        SqlDataAdapter sqlDa = new SqlDataAdapter("ContactViewByID", sqlCon);
        sqlDa.SelectCommand.CommandType = CommandType.StoredProcedure;
        sqlDa.SelectCommand.Parameters.AddWithValue("@ContactID", ContactID);

        DataTable dtbl = new DataTable();
        sqlDa.Fill(dtbl);

        sqlCon.Close();

        hfContactID.Value = ContactID.ToString();
        txtName.Text = dtbl.Rows[0]["Name"].ToString();
        txtMobile.Text = dtbl.Rows[0]["Mobile"].ToString();
        txtAddress.Text = dtbl.Rows[0]["Address"].ToString();
        btnSave.Text = "Update";
        btnDelete.Enabled = true;
    }

    protected void btnDelete_Click(object sender, EventArgs e)
    {
        if (sqlCon.State == ConnectionState.Closed)
            sqlCon.Open();

        SqlCommand sqlCmd = new SqlCommand("ContactDeleteByID", sqlCon);
        sqlCmd.CommandType = CommandType.StoredProcedure;
        sqlCmd.Parameters.AddWithValue("@ContactID", Convert.ToInt32(hfContactID.Value));

        sqlCmd.ExecuteNonQuery();

        sqlCon.Close();
        Clear();
        FillGridView();
        lblSuccessMessage.Text = "Deleted Successfully";
    }
}

Answer 1

您永远都不会指定要调用什么存储过程来填充数据集。

更改这些行：

SqlDataAdapter sqlDa = new SqlDataAdapter(sqlCon);
sqlDa.SelectCommand.CommandType = CommandType.StoredProcedure;

到

SqlDataAdapter sqlDa = new SqlDataAdapter("dbo.YourStoredProcedureName", sqlCon);
sqlDa.SelectCommand.CommandType = CommandType.StoredProcedure;

，然后您还将为使用字符串（要执行的命令）的SqlDataAdapter和SqlConnection调用正确构造函数。

无法从“ System.Data.SqlClient.SqlConnection”转换为“ System.Data.SqlClient.SqlCommand”

1 个答案: