从另一个表单捕获文本框事件

Question

I have an event in my Form:

 public void filterByType_TextChanged(object sender, EventArgs e)
    {
        dSearch = new D_Search(this);
        dSearch.filterD(); }

which calls a function in another class. What I want to do is that I want to notice in my class which Textbox was altered and do something. So there are multiple functions like the one above and they all call the "filterD()" function in my DSearch class. I tried

if (sender == form1.filterByType_TextChanged)
        { sqlCmd = new SqlCommand("SELECT * FROM" } //SQL Statement
        }

     datTable = new DataTable();
        sqlDatAdapter = new SqlDataAdapter(sqlCmd.CommandText, 
        connection);
        sqlDatAdapter.Fill(datTable);

        form1.setDataGrid = datTable;

but he can't find "sender" I also tried to create a new Button within the function in my Form and pass it but it doesn't seem to work.

Answer 1

try this -

In form 1

private void textBox1_TextChanged(object sender, EventArgs e)
{
     var dSearch = new D_Search(this);
     MessageBox.Show(dSearch.filterD(sender));
}

D_Search class

public class D_Search
{
    Form1 frm = null;

    public D_Search(Form1 frm1)
    {
        frm = frm1;
    }

    public string filterD(object sender)
    {
        string val = String.Empty;
        if (sender == frm.textBox1)
        {
            val = (sender as TextBox).Text;
        }
        return val;
    }
}

also if you want to access filterByType_TextChanged textbox in other class then change its modifier property to Internal