从windows app中的usercontrol访问值 [英] Accessing the value from usercontrol in windows app

问题描述

我有一个名为AddRow的用户控件和一个名为TimeSheet的表单，Timesheet有一个save_btn事件，点击save_btn后，在usercontrol中输入的值应写入数据库，但我无法从usercontrol访问该值



以下是代码

  public   void  save_btn_Click（ object  sender，EventArgs e）
 {
 
 SqlCommand cmdinsert =  new  SqlCommand（ 插入TimeSheet（Project_Name，Activity_Name，周一，周二，周三，周四，周五，周六，周日）值（@ Project_Name，@ Activity_Name，@ Monday，@ Tuesday，@ Wednesday，@ Thursday，@ Friday，@ Saturday，@星期天），con）; 
 cmdinsert.Parameters.AddWithValue（  @ Project_Name，添加 .project_cbox.SelectedIndex）; 
 cmdinsert.Parameters.AddWithValue（  @ Activity_Name，activity_cb.SelectedIndex）; 
 cmdinsert.Parameters.AddWithValue（  @ Monday，添加 .monday_txt_val）; 
 cmdinsert.Parameters.AddWithValue（  @ Tuesday，添加 .tuesday_txt_val）; 
 cmdinsert.Parameters.AddWithValue（  @ Wednesday，添加 .wednesday_txt.Text）; 
 cmdinsert.Parameters.AddWithValue（  @ Thursday，添加 .thursday_txt.Text）; 
 cmdinsert.Parameters.AddWithValue（  @ Friday，添加 .friday_txt.Text）; 
 cmdinsert.Parameters.AddWithValue（  @ Saturday，添加 .saturday_txt.Text）; 
 cmdinsert.Parameters.AddWithValue（  @ Sunday，添加 .sunday_txt.Text）; 
 con.Open（）; 
 cmdinsert.ExecuteNonQuery（）; 
 con.Close（）; 
 
} 

此事件在时间表中，但值为空字符串...我无法访问价值，有解决方案吗？这是窗口应用程序

  public   string  monday_txt_val 
 {
  get  
 {
  return  monday_txt.Text; 
} 
 
  set  
 {
 monday_txt.Text = 值; 
} 
} 

monday_txt是一个在输入值后动态创建的文本框，但它正在读取一个空字符串，尽管我在文本框中输入了一个值，当它传递给monday_txt的表格值为空字符串时，如何解决这个问题？



唯一方法我可以想到访问monday_txt是通过在Timesheet中创建一个AddRow实例。但是当创建新实例时我将无法获得该值，请帮助

解决方案

< blockquote>你不想创建一个新实例 - 你需要获得你动态创建的UserControl的实际实例并呈现给用户供他填写。有两种方法：

1）当你调用new AddRow（）来添加控件时，在表单类中保持类级引用，

2）查看Form.Controls集合以查找AddRow实例 - 记住如果你把它添加到面板或其他容器，你会需要通过容器递归才能找到它。

I have a usercontrol called AddRow and a form called TimeSheet ,Timesheet has a save_btn event, on click of save_btn the value enter in usercontrol should be written to database,but I am not able to access the value from usercontrol

below is the code

public void save_btn_Click(object sender, EventArgs e)
    {

        SqlCommand cmdinsert = new SqlCommand("insert into TimeSheet (Project_Name ,Activity_Name,Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday) values (@Project_Name,@Activity_Name,@Monday,@Tuesday,@Wednesday,@Thursday,@Friday,@Saturday,@Sunday) ", con);
        cmdinsert.Parameters.AddWithValue("@Project_Name",  add.project_cbox.SelectedIndex);
        cmdinsert.Parameters.AddWithValue("@Activity_Name", activity_cb.SelectedIndex);
        cmdinsert.Parameters.AddWithValue("@Monday", add.monday_txt_val);
        cmdinsert.Parameters.AddWithValue("@Tuesday", add.tuesday_txt_val);
        cmdinsert.Parameters.AddWithValue("@Wednesday", add.wednesday_txt.Text);
        cmdinsert.Parameters.AddWithValue("@Thursday", add.thursday_txt.Text);
        cmdinsert.Parameters.AddWithValue("@Friday", add.friday_txt.Text);
        cmdinsert.Parameters.AddWithValue("@Saturday", add.saturday_txt.Text);
        cmdinsert.Parameters.AddWithValue("@Sunday", add.sunday_txt.Text);
        con.Open();
        cmdinsert.ExecuteNonQuery();
        con.Close();  

    }

this event is in timesheet but the value is empty string...I just cant access the value,is there a solution? this is window application

public string monday_txt_val
    {
        get
        {
            return monday_txt.Text;
        }

        set
        {
            monday_txt.Text = value;
        }
    }

monday_txt is a textbox that is created dynamically,after the value is entered ,but it is reading a empty string,despite me entering a value in textbox,when it is passed to form value of monday_txt is empty string,how to fix this?

only way I can think of accessing monday_txt is by creating a instance of AddRow in Timesheet..but When new instance is created I will not be able to get the value, kindly help

解决方案

You don''t want to create an new instance - you need to get the actual instance of the UserControl that you created dynamically and presented to the user for him to fill in. There are two ways:
1) Keep a class level reference in your form class when you call new AddRow() to add the control,
2) Look through the Form.Controls collection to find the AddRow instance - remember that if you add it to a panel or other container, you will need to recurse through containers to find it.

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