C# Windows 表单：遍历动态创建的文本框并检查文本是否已更改

Question

我正在尝试创建一个图形化的 SQL 编辑器 - 但我不喜欢 table 的视觉效果，我正在尝试添加更多交互性（drag/drop等）。

我已经根据每条记录浏览并创建了面板，并根据我的 table 中的每条记录向每个面板添加了文本框。我现在坚持的是循环动态创建的控件并检查它们的状态或与它们交互的概念。

如果您发现我的结构有问题，请告诉我。

我的代码如下：

生成面板的代码：

  private void comboBox1_SelectedIndexChanged_1(object sender, EventArgs e)
    {
        groupBox1.Controls.Clear();
        string pDBString = null;
        SqlConnection cnn;
        pDBString = "Data Source=localhost\" + Form1.host + ";Initial Catalog=" + Form1.db + ";Integrated Security=SSPI;";
        cnn = new SqlConnection(pDBString);
        string sqlForProps = "select * from PROPS where user_id_txt ='" + comboBox1.SelectedItem.ToString() + "'";
        try
        {
            using (cnn)
            {
                cnn.Open();
                SqlCommand cmd = new SqlCommand(sqlForProps, cnn);
                SqlDataReader sqlReader = cmd.ExecuteReader();

                int x = 0;
                int count = 0;
                while (sqlReader.Read())
                {
                    Panel panel = new System.Windows.Forms.Panel();
                    panel.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
                    x += 30;
                    panel.Location = new System.Drawing.Point(3, x);
                    panel.Name = "panel" + count;
                    panel.Size = new System.Drawing.Size(519, 30);
                    panel.TabIndex = 3;
                    PropsPanels.Add(panel);
                    groupBox1.Controls.Add(panel);

                    TextBox textbox = new System.Windows.Forms.TextBox();
                    panel.Controls.Add(textbox);
                    textbox.Location = new System.Drawing.Point(1, 3);
                    textbox.Name = "textBox" + count;
                    textbox.Size = new System.Drawing.Size(100, 20);
                    textbox.TabIndex = 4;
                    textbox.Text = sqlReader["USER_ID_TXT"].ToString();

                    TextBox textboxAM = new System.Windows.Forms.TextBox();
                        panel.Controls.Add(textboxAM);
                        textboxAM.Location = new System.Drawing.Point(126, 3);
                        textboxAM.Name = "textBoxAM" + count;
                        textboxAM.Size = new System.Drawing.Size(100, 20);
                        textboxAM.TabIndex = 4;
                        textboxAM.Text = sqlReader["PROP_TXT"].ToString();

                    TextBox textboxAMSet = new System.Windows.Forms.TextBox();
                        panel.Controls.Add(textboxAMSet);
                        textboxAMSet.Location = new System.Drawing.Point(232, 3);
                        textboxAMSet.Name = "textBoxAM" + count;
                        textboxAMSet.Size = new System.Drawing.Size(100, 20);
                        textboxAMSet.TabIndex = 4;
                        textboxAMSet.Text = sqlReader["VAL_TXT"].ToString();
                    count++;
                }
                sqlReader.Close();
                cnn.Close();
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show("Can not open connection !");
        }

    }

假设要检查面板的代码：

        public AMMain()
    {

        InitializeComponent();
        string pDBString = null;
        SqlConnection cnn;
        pDBString = "Data Source=US7-AHACKETT\SQLEXPRESS;Initial Catalog=OrchestroConfigurationDB;Integrated Security=SSPI;";
        MessageBox.Show(pDBString);
        cnn = new SqlConnection(pDBString);
        try
        {
            using (cnn)
            {
                SqlCommand sqlForUserList = new SqlCommand("select UserName from users a join Company b on a.CompanyID = b.CompanyID where CompanyCode='" + Form1.company + "'", cnn);
                cnn.Open();
                MessageBox.Show("Connection Open !");
                SqlDataReader sqlReader = sqlForUserList.ExecuteReader();
                while (sqlReader.Read())
                {
                    comboBox1.Items.Add(sqlReader["UserName"].ToString());
                }
                sqlReader.Close();
                cnn.Close();
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show("Can not open connection !");
        }

        foreach (Panel p in PropsPanels)
        {
            foreach (Control c in p.Controls)
            {
                if(c is TextBox)
                {
                    object sender = new object();
                    EventArgs e = new EventArgs();
                    if(c.TextChanged()??????)
                    {
                     //DOSOMETHING   
                    }
                }
            }
        }
    }

例如：如果我想检查我放置在表单上的文本框的文本是否更改，我会这样做：

        private void textBox1_TextChanged(object sender, EventArgs e)
    {

    }

所以我想我无法理解如何在运行时间检查它，因为我在运行时间创建文本框。

感谢您的帮助！

Answer 1

For example: if I wanted to check if text changed for a textbox that I put on the form I would do so:
private void textBox1_TextChanged(object sender, EventArgs e)
{

}
So I guess I can't wrap my head around how I would check this at run-time since I am creating the Textboxes at runtime.

你也一样！

先创建一个方法来处理事件：

private void TextBoxTextChanged(object sender, EventArgs e) {
    // you can use the sender argument to check exactly which text box's text changed
}

初始化表单时，您可以这样做：

textbox.TextChanged += TextBoxTextChanged;
textboxAM.TextChanged += TextBoxTextChanged;
textboxAMSet.TextChanged += TextBoxTextChanged;

Answer 2

您可以像手动将文本框放置到位一样执行此操作。您只需订阅每个新 TextBox 的 TextChanged 事件。

var x = new TextBox();

x.TextChanged += textBox1_TextChanged;

在旧版本的 .Net 中，您可能需要指定委托。有关详细信息，请参阅 MSDN on the subject。

Answer 3

创建控件时需要在 TextChanged 委托上注册。

TextBox textbox = new System.Windows.Forms.TextBox();
panel.Controls.Add(textbox);
textbox.Location = new System.Drawing.Point(1, 3);
textbox.Name = "textBox" + count;
textbox.TextChanged += TextBox_TextChanged

然后，在事件处理程序中，使用 sender 参数转换为触发事件的控件实例。

  private void(object sender, EventArgs e)
    {
        //get name of textbox
        var tb = (TextBox) sender;
        // do whatever with text box
    }

C# Windows 表单：遍历动态创建的文本框并检查文本是否已更改

C# Windows Form: Looping through Dynamically created TextBoxes and checking to see if Text has changed

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panels

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