Question

<div class="row500">
   <span class="cell200">
   <asp:DropDownList ID="ddlCollision" runat="server" Height="28px" Width="354px" Style="font-size: 18px" OnSelectedIndexChanged="ddlCollision_SelectedIndexChanged" AutoPostBack="True">
     
<asp:ListItem Value="0"></asp:ListItem>
<asp:ListItem Value="1">Cars</asp:ListItem>
<asp:ListItem Value="2">People</asp:ListItem>
  </asp:DropDownList>
 </span>
</div>

<br/>
 <div class="row500"  id="fixedObject" runat="server">
    <span class="cell200">
    <asp:Label ID="lblFixed" runat="server" Text="Car Label:"> </asp:Label>
            </span>
            <br />
       
    <span class="cell200">
    <asp:TextBox ID="TextBox9" runat="server">     </asp:TextBox>    
   </span>
   </div>

我目前正在开发一个asp.net C＃网页，其中包含一个下拉列表，其中大约有5个列表项，其值为0-4。每当用户选择其中一个项目时，我希望该数字与将出现的文本框的数量相对应。因此，如果用户从下拉列表中选择“2”，我需要显示/隐藏包含文本框的div并显示2个文本框。对此的任何帮助都会很棒!!!!

我的尝试：下拉列表中的代码

protected void ddlCollision_SelectedIndexChanged(object sender, EventArgs e)
{
    if (ddlCollision.SelectedValue == "1")
        fixedObject.Visible = true;
    else
        fixedObject.Visible = false;
}

fixed object是包含文本框的div的id

Answer 1

您甚至可以根据从下拉列表中选择的整数计数动态添加文本框。然后，对于那个et1 = (EditText)findViewById(R.id.editText); et2 = (EditText)findViewById(R.id.editText2); et3 = (EditText)findViewById(R.id.editText3); et1.addTextChangedListener(new TextWatcher() { @Override public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) { } @Override public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) { if (getCurrentFocus() == et1) { if (et1.getText().toString().equals("")) { et2.setText("0"); et3.setText("0"); } else { String s1 = et1.getText().toString(); Double d1 = Double.parseDouble(s1); Double d3 = d1 * 12; String s3 = Double.toString(d3); et2.setText(s3); Double d4 = d1 * 0.3048; String s4 = Double.toString(d4); et3.setText(s4); } } } @Override public void afterTextChanged(Editable editable) {} }); et2.addTextChangedListener(new TextWatcher() { @Override public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) { } @Override public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) { if (getCurrentFocus() == et2) { if (et2.getText().toString().equals("")) { et1.setText("0"); et3.setText("0"); } else { String s1 = et2.getText().toString(); Double d1 = Double.parseDouble(s1); Double d3 = d1 / 12; String s3 = Double.toString(d3); et1.setText(s3); Double d4 = d1 * 39.40; String s4 = Double.toString(d4); et3.setText(s4); } } @Override public void afterTextChanged(Editable editable) { } }); et3.addTextChangedListener(new TextWatcher() { @Override public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2){ } @Override public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) { if (getCurrentFocus() == et3) { if (et3.getText().toString().equals("")) { et2.setText("0"); et1.setText("0"); } else { String s1 = et3.getText().toString(); Double d1 = Double.parseDouble(s1); Double d3 = d1 * 39.40; String s3 = Double.toString(d3); et1.setText(s3); Double d4 = d1 / 3.48; String s4 = Double.toString(d4); et3.setText(s4); } } @Override public void afterTextChanged(Editable editable) {} }); }次，它将运行并添加许多文本框。

static wrapClass(target, {hook = noop} = {}) {
  return class wrapper extends target {
    static get wrappedClass() {
      return target;
    }

    constructor(...args) {
      super(...Injector.fromParams(args).getDependencies(wrapper).concat(args));
    }
  }

count

Answer 2

protected void ddlOptions_SelectedIndexChanged（object sender，EventArgs e） {

        Int32 pickedValue = Int32.Parse(ddlOptions.SelectedValue);

            Table table = new Table();


            for (int i = 1; i <= pickedValue; i++)
            {

                TableRow row = new TableRow();
                TableCell cell = new TableCell();
                cell.Attributes.Add("runat", "server");

                TextBox txt_splzn = new TextBox();

                txt_splzn.ID = "txtB" + i.ToString();
                txt_splzn.Text = "Text Number " + i.ToString();

                cell.Controls.Add(txt_splzn);

                row.Cells.Add(cell);
                table.Rows.Add(row);
                ctrlPlaceholder.Controls.Add(table);
            }
        }

}

DropDown Box选项显示C＃中的文本框

2 个答案: