Question

我想在asp.net

中动态创建文本框值

这是我在此代码文本框中创建的代码，但是当我在文本中输入值并从动态创建的文本框中检索值时，它会给出错误

对象引用未设置为对象的实例

以下是我的代码......

protected void Page_Init(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        //Generate initial textboxes 
        GenerateButton_Click(sender, e);
    }
}
protected void GenerateButton_Click(object sender, EventArgs e)
{
    //Generate textboxes 
    int z = int.Parse(HowManyToGenerateTextBox.Text);

    Panel1.Controls.Clear();

    for (int i = 0; i < z; i++)
    {
        TextBox s = new TextBox();
        s.ID = "tb" + i.ToString();
        Session[s.ID] = s;
        Panel1.Controls.Add(s);
    }
}
protected void CalculateButton_Click(object sender, EventArgs e)
{
    //Calculate sum 
    int sum = 0;

    for (int i = 0; i < Session.Count; i++)
    {
        TextBox txt = (TextBox)Panel1.FindControl("tb" + i.ToString());
        ResultLabel.Text = txt.Text;


        if (ResultLabel.Text != null)
            sum += int.Parse(ResultLabel.Text);
    }

    ResultLabel.Text = sum.ToString();
}

Answer 1

我认为问题出在这一行

for (int i = 0; i < Session.Count; i++)

会话始终包含其他参数

在Session.Count方法中将z与GenerateButton_Click进行比较。我想他们是不同的

Answer 2

Hello Friend以下是答案

 protected void Page_Load(object sender, EventArgs e)
{
    if (Page.IsPostBack)
        GenerateButton_Click(sender, e);
}


public TextBox[] s;

protected void GenerateButton_Click(object sender, EventArgs e)
{

  int z = Convert.ToInt32(HowManyToGenerateTextBox.Text);
  Panel1.Controls.Clear();
  Array.Resize(ref s, z);
  for (int i = 0; i < z; i++)
  {
      s[i] = new TextBox();
      s[i].ID = "tb" + i.ToString();
      s[i].Text = "tb" + i.ToString();
      Session[s[i].ID] = s;
      Panel1.Controls.Add(s[i]);
  }
}
protected void CalculateButton_Click(object sender, EventArgs e)
{
   ResultLabel.Text = s[0].Text;      
}

这也是代码 http://www.codeproject.com/Questions/854773/How-to-get-dynamically-created-textbox-value

如何获取动态创建的文本框值

2 个答案: