求TEXTBOX控件中只能输入50的倍数 而且是初始化时自动生成50的倍数 不能是负的

Question

RTRT

Answer 1

 <asp:TextBox ID="TextBox1" runat="server" onblur="checkInput(this)"></asp:TextBox>
        
        <script type="text/javascript">
        function checkInput(obj)
        {
            var v=obj.value;
            v=parseInt(v);
            if(isNaN(v))
            {
              alert("请输入50的倍数的数字")
              return false;
             }
             if(v%50!=0)
             {
              alert("请输入50的倍数的数字")
              return false;             
             }
             if(v<50)
             {
             
              alert("请输入50的倍数的数字")
              return false;
              }
              return true;
        
        }
        </script> protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            Random rd=new Random();
            int value=50*rd.Next(1,10);
            this.TextBox1.Text = value.ToString();
        }
    }