从Dropdownlist（Asp.net C＃）中选择值时如何自动填充文本框 [英] How to Auto populate a text box when selecting a value from Dropdownlist (Asp.net C#)

问题描述

如何从Dropdownlist（Asp.net C＃）中选择值时自动填充文本框

（Iam遵循分层结构）





简单地说，我从下拉列表中选择一个值...它

ddlVndrName.DataSource = objVndrList;

ddlVndrrName.DataValueField = VndrID;

ddlVndrName.DataTextField =VndrName;

ddlVndrName.DataBind（）;

如何用PhoneNumber填充文本框对应到db中的上述VndrID

解决方案

将AutoPostback属性设置为DropDownList的True并且编写代码以在DropDownList1_SelectedIndexChanged事件中获取phonenumber。

Quote：

但Iam使用3tier架构

然后在每个层中编写一个方法，并尝试将参数从一个层传递到另一个层并获取数据。

如果要弹出从数据库中获取并拥有类似PhoneNumber的数据。简单

 <  < span class =code-leadattribute> asp：DropDownList     ID   =  ddlVndrName    runat   =  server    AutoPostBack   =  True < span class =code-attribute>   onselectedindexchanged   =  ddlVndrName_SelectedIndexChanged /> 

然后代码

 受保护  void  ddlV ndrName_SelectedIndexChanged（ object  sender，EventArgs e）
 {
  string  selectedValue = ddlVndrName。 SelectedValue.Tostring（）; 
 
 
 TextBox1.Text = GetData（selectedValue）; 
 
} 
 
  public   string  GetData（< span class =code-keyword> string  id）
 {
  var  ConnectionString =  您的连接字符串; 
  var  query =  string  .formet（SELECT PhoneNumber FROM tableName WHERE id = { 0 }，id}; 
 使用（ var  conn =  new  SqlConnection（ConnectionString））
 {
  try  
 {
  if （conn.State == ConnectionState.Closed）
 {
 conn.Open（）; 
} 
 
  string  returnValue =  string  .Empty; 
 < span class =code-keyword> var  selectCommand =  new  SqlCommand（query，conn）; 
 
  var  myReader = selectCommand。的ExecuteReader（）; 
  while （myReader.Read（））
 {
 returnValue = myReader.GetString（ 0 ）; 
} 
 
  if （conn.State == ConnectionState.Open）
 {
 conn.Close （）; 
} 
  return  returnValue; 
} 
} 
  catch （例外e）
 {
  throw   new 异常（e.Message）; 
} 
 
} 

How to Auto populate a text box when selecting a value from Dropdownlist (Asp.net C#)
(Iam following layered structure)


simply say that ,iam selecting a value from dropdownlist...its
ddlVndrName.DataSource = objVndrList;
ddlVndrrName.DataValueField = "VndrID";
ddlVndrName.DataTextField = "VndrName";
ddlVndrName.DataBind();
How to populate a textbox with PhoneNumber corresponds to the above VndrID in db

解决方案

Hi,

Set AutoPostback property as True of the DropDownList and write code to fetch phonenumber in DropDownList1_SelectedIndexChanged event.

Quote:

But Iam using 3tier architecture

Then write a method in each tier and try to pass parameter from one tier to other and fetch the data.

If you want to populate from database and have a data filed like PhoneNumber then. simple

<asp:DropDownList ID="ddlVndrName" runat="server" AutoPostBack="True" onselectedindexchanged="ddlVndrName_SelectedIndexChanged/>"

Then code behind

protected void ddlVndrName_SelectedIndexChanged(object sender, EventArgs e)
{
  string selectedValue = ddlVndrName.SelectedValue.Tostring();


  TextBox1.Text = GetData( selectedValue);

}

public string GetData(string id)
{
var ConnectionString= "your connection string";
var query = string.formet( SELECT PhoneNumber FROM tableName WHERE id ={0},id};
 using (var conn = new SqlConnection(ConnectionString))
          {
              try
              {
                  if (conn.State == ConnectionState.Closed)
                  {
                      conn.Open();
                  }

                  string returnValue = string.Empty;
                  var selectCommand = new SqlCommand(query, conn);

                      var myReader = selectCommand.ExecuteReader();
                      while (myReader.Read())
                      {
                          returnValue = myReader.GetString(0);
                      }

                  if (conn.State == ConnectionState.Open)
                  {
                      conn.Close();
                  }
                  return returnValue;
              }
          }
          catch (Exception e)
          {
             throw new Exception(e.Message);
          }

}

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