文本框验证不工作 [英] Text box validation not working

问题描述

现在下面的测试代码的空白文本框。如果是空白的它返回的if语句下面指出的错误。这工作正常，但我也希望它检查是否有空格。我已经尝试了第一个以下内容：

 如果（String.IsNullOrWhiteSpace（txtFirstName.Text））
  

它不工作，虽然。我输入单词自行车在文本框中，但我拼写它像B IKE用空格来看看它是否会返回错误信息，并没有这样做。

 公共部分类frmPersonnel：System.Web.UI.Page 
 {
保护无效btnSubmit_Click（对象发件人，EventArgs五）
 $ { b $ b //lblError.Text =; 
试
 {
如果（txtFirstName.Text ==）
 {
 txtFirstName.BackColor = System.Drawing.Color.Yellow; 
 lblError.Text + =请输入名字< BR />中; 
} 
 
如果（txtLastName.Text ==）
 {
 txtLastName.BackColor = System.Drawing.Color.Yellow; 
 lblError.Text + =请输入姓氏<！BR />中; 
} 
如果（txtPayRate.Text ==）
 {
 txtPayRate.BackColor = System.Drawing.Color.Yellow; 
 lblError.Text + =请输入工资标准<！BR />中; 
} 
如果（txtStartDate.Text ==）
 {
 txtStartDate.BackColor = System.Drawing.Color.Yellow; 
 lblError.Text + =请输入开始日期<！BR />中; 
} 
如果（txtEndDate.Text ==）
 {
 txtEndDate.BackColor = System.Drawing.Color.Yellow; 
 lblError.Text + =请输入结束日期<！BR />中; 
} 
 
的DateTime DT1; 
日期时间DT2; 
 
 DT1 = DateTime.Parse（txtStartDate.Text）; 
 DT2 = DateTime.Parse（txtEndDate.Text）; 
 
 
如果（DateTime.Compare（DT1，DT2）0）
 {
 txtStartDate.BackColor = System.Drawing.Color.Yellow; 
 txtEndDate.BackColor = System.Drawing.Color.Yellow; 
 lblError.Text + =开始日期不得超过结束日期大于<！BR />中; 
} 
 
，否则
 {
会话[txtFirstName] = txtFirstName.Text; 
会话[txtLastName] = txtLastName.Text; 
会话[txtPayRate] = txtPayRate.Text; 
会话[txtStartDate] = txtStartDate.Text; 
会话[txtEndDate] = txtEndDate.Text; 
 Server.Transfer的（frmPersonalVerified.aspx）; 
} 
} 
赶上（例外）
 {
 
} 
} 
} 
  

解决方案

我会改变以下类型的测试：

 如果（txtFirstName.Text ==）
  

要：

 如果（string.IsNullOrWhiteSpace（txtFirstName.Text））// .NET 4.0 + 
 
如果（string.IsNullOrEmpty（txtFirstName.Text））// .NET 4.0之前，
  

并为您的附加试验（字符串中不允许使用空格）：

 如果（string.IsNullOrWhiteSpace（txtFirstName.Text）及&安培;！txtFirstName.Text.Contains（））// .NET 4.0 + 
 
如果（string.IsNullOrEmpty（txtFirstName.Text）及和放大器;！txtFirstName.Text.Contains（ ））// .NET 4.0之前，
  

请注意：

您将需要检查 lblError.Text 不含才能继续到下一个页面什么，因为这是握着你的错误。我只能看到的DateTime 测试，所以即使你的任何 TXT 控件都失败了验证，你还是转

Right now the code below tests for a blank text box. If it is blank it returns the error stated below the if statement. That works fine, but I also want it to check for white spaces. I have tried the following for the first one:

if (String.IsNullOrWhiteSpace(txtFirstName.Text))

It does not work though. I typed the word "Bike" into the text box, but I spelled it like "B ike" with a space to see if it would return the error message and it didn't.

public partial class frmPersonnel : System.Web.UI.Page
{
    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        //lblError.Text = "";
        try
        {
            if (txtFirstName.Text == "")
            {
                txtFirstName.BackColor = System.Drawing.Color.Yellow;
                lblError.Text += "Please enter first name<br />";
            } 

            if (txtLastName.Text == "")
            {
                txtLastName.BackColor = System.Drawing.Color.Yellow;
                lblError.Text += "Please enter last name! <br />";
            }
            if (txtPayRate.Text == "")
            {
                txtPayRate.BackColor = System.Drawing.Color.Yellow;
                lblError.Text += "Please enter pay rate! <br />";
            }
            if (txtStartDate.Text == "")
            {
                txtStartDate.BackColor = System.Drawing.Color.Yellow;
                lblError.Text += "Please enter start date! <br />";
            }
            if (txtEndDate.Text == "")
            {
                txtEndDate.BackColor = System.Drawing.Color.Yellow;
                lblError.Text += "Please enter end date! <br />";
            }

            DateTime dt1;
            DateTime dt2;

            dt1 = DateTime.Parse(txtStartDate.Text);
            dt2 = DateTime.Parse(txtEndDate.Text);


            if (DateTime.Compare(dt1, dt2) > 0)
            {
                txtStartDate.BackColor = System.Drawing.Color.Yellow;
                txtEndDate.BackColor = System.Drawing.Color.Yellow;
                lblError.Text += "Start Date must not be greater than End Date! <br />";
            }

            else
            {
                Session["txtFirstName"] = txtFirstName.Text;
                Session["txtLastName"] = txtLastName.Text;
                Session["txtPayRate"] = txtPayRate.Text;
                Session["txtStartDate"] = txtStartDate.Text;
                Session["txtEndDate"] = txtEndDate.Text;
                Server.Transfer("frmPersonalVerified.aspx");
            }
        }
        catch (Exception)
        {

        }
    }
}

解决方案

I would change the following type of test:

if (txtFirstName.Text == "")

To:

if (string.IsNullOrWhiteSpace(txtFirstName.Text)) // .NET 4.0+

if (string.IsNullOrEmpty(txtFirstName.Text)) // .NET before 4.0

And for your additional test (no spaces allowed in the string):

if (string.IsNullOrWhiteSpace(txtFirstName.Text) && !txtFirstName.Text.Contains(" ")) // .NET 4.0+

if (string.IsNullOrEmpty(txtFirstName.Text) && !txtFirstName.Text.Contains(" ")) // .NET before 4.0

Note:

You will need to check that lblError.Text doesn't contain anything in order to continue to the next page, as this is what holds your errors. I can only see the DateTime test, so even if any of your txt controls have failed the validation, you still transfer.

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