c# - 我只是尝试按学校名称搜索结果。但是网格视图没有显示任何内容

Question

这是我的代码...我只是尝试按学校名称搜索结果。但是网格视图没有显示任何东西。我的代码是

public void gridfill()
{
    markSp spMark = new markSp();
    DataTable dtbl = new DataTable();
    dtbl = spMark.markViewAll();
    gvResult.DataSource = dtbl;
    dtbl = spMark.markViewBySchool(txtSchoolName.Text);
    gvResult.DataSource = dtbl;    
}
protected void Button1_Click(object sender, EventArgs e)
{
    gridfill();
}
public DataTable markViewAll()
{
    DataTable dtbl = new DataTable();
    SqlDataAdapter sqlda = new SqlDataAdapter("markViewAll", sqlcon);
    sqlda.SelectCommand.CommandType = CommandType.StoredProcedure;
    sqlda.Fill(dtbl);
    return dtbl;
}
public DataTable markViewBySchool(string viewBySchool)
{
    DataTable dtbClass = new DataTable();
    SqlDataAdapter sqlda = new SqlDataAdapter("markViewBySchool",sqlcon);
    sqlda.SelectCommand.CommandType = CommandType.StoredProcedure;
    sqlda.SelectCommand.Parameters.Add("@schoolName", SqlDbType.VarChar).Value = viewBySchool;
    sqlda.Fill(dtbClass);
    return dtbClass;
}

Answer 1

更改如下，您的代码中几乎没有问题，为什么两次数据绑定到同一个gridview？即使您数据绑定了两次，它也只会显示您上次设置的内容。我删除了几行代码，你也忘了gvResult.DataBind()打电话

public void gridfill()
{
    markSp spMark = new markSp();
    gvResult.DataSource = spMark.markViewBySchool(txtSchoolName.Text);
    gvResult.DataBind();  
}

Answer 2

由于您已使用 ASP.Net 进行标记，因此您需要调用DataBind

gvResult.DataBind();

所以你的方法是：

public void gridfill()
{
    markSp spMark = new markSp();
    DataTable dtbl = new DataTable();
    dtbl = spMark.markViewAll(); //you are not using this anywhere
    gvResult.DataSource = dtbl;  // so you can get rid of these two lines
    dtbl = spMark.markViewBySchool(txtSchoolName.Text);
    gvResult.DataSource = dtbl;    
    gvResult.DataBind(); // This is missing
}

您应该看到：ASP.NET 数据绑定概述

Answer 3

 public void gridfill()
{
      markSp spMark = new markSp();
     DataTable dtbl = new DataTable();
     dtbl = spMark.markViewAll();

     dtbl = spMark.markViewBySchool(txtSchoolName.Text);
     gvResult.DataSource = dtbl; 
     gvResult.Databind(); // You forgot DataBind()  
  }