动态创建的标签和文本框

Question

Generating only 1 textbox field and label. my plan is to generate only 4 fields in 1 panel

private void btnAdd_Click(object sender, EventArgs e)
{
    Label label = new Label();
    int count = panel1.Controls.OfType<Label>().ToList().Count;
    label.Location = new Point(10, (25 * count) + 2);
    label.Size = new Size(40, 20);
    label.Top = 4;
    label.ForeColor = System.Drawing.Color.White;
    label.Name = "label_" + (count + 1);
    label.Text = "Field " + (count + 1);
    panel3.Controls.Add(label);

    TextBox textbox = new TextBox();
    count = panel1.Controls.OfType<TextBox>().ToList().Count;
    textbox.Location = new Point(60, 25 * count);
    textbox.Top = 4;
    textbox.Size = new Size(301, 20);
    textbox.Name = "textbox_" + (count + 1);
    textbox.TextChanged += new System.EventHandler(this.TextBox_Changed);
    panel3.Controls.Add(textbox);
}

Answer 1

You can use a for loop to add more than one textbox and label at the same time and you have to remove textbox.Top = 4; because your overwriting label.Location = new Point(10, (25 * count) + 2); and all of your controls will have the same position.

private void btnAdd_Click(object sender, EventArgs e)
{
    for (int count = 0;count < 4; count++)
    {
        Label label = new Label();
        label.Location = new Point(10, (25 * count) + 2);
        label.Size = new Size(40, 20);
        label.ForeColor = System.Drawing.Color.White;
        label.Name = "label_" + (count + 1);
        label.Text = "Field " + (count + 1);
        panel3.Controls.Add(label);

        TextBox textbox = new TextBox();
        textbox.Location = new Point(60, 25 * count);
        textbox.Size = new Size(301, 20);
        textbox.Name = "textbox_" + (count + 1);
        textbox.TextChanged += new System.EventHandler(this.TextBox_Changed);
        panel3.Controls.Add(textbox);
    }        
}

If you want to add one textbox and label per click you can declare a field int count that counts the number of created control pairs:

int count = 0;
private void button1_Click(object sender, EventArgs e)
{
        Label label = new Label();
        label.Location = new Point(10, (25 * count) + 2);
        label.Size = new Size(40, 20);
        label.ForeColor = System.Drawing.Color.White;
        label.Name = "label_" + (count + 1);
        label.Text = "Field " + (count + 1);
        panel3.Controls.Add(label);

        TextBox textbox = new TextBox();
        textbox.Location = new Point(60, 25 * count);
        textbox.Size = new Size(301, 20);
        textbox.Name = "textbox_" + (count + 1);
        textbox.TextChanged += new System.EventHandler(this.TextBox_Changed);
        panel3.Controls.Add(textbox);
        count++;
}