c# - 我的现场验证似乎不起作用!我在这里错过了什么吗？

Question

我正在尝试验证字段，以便用户不能输入带有空字段的数据。问题是我仍在添加空字段，因此我的验证无效。

首先，我要检查是否从组合框中选择了类型。然后我检查用户是否选择了哪种类型，然后根据类型我在输入数据之前检查字段中是否有空字符串。

我是不是漏掉了什么？

private void btnAddEntry_Click(object sender, EventArgs e)
{
    // Multiple level field validations.
    if (cmbType.SelectedIndex != -1)
    {
        if (cmbType.SelectedIndex == 0 && 
            (txtUserName.Text != string.Empty || 
            txtPassword.Text != string.Empty))
        {
            string SQL =
                "INSERT INTO PersonalData([Type], [UserName], [Password]) " +
                "VALUES(@Type, @UserName, @Password)";

            InsertData(SQL);
        }
        else if (cmbType.SelectedIndex == 1 && 
            (txtURL.Text != string.Empty || 
            txtUserName.Text != string.Empty || 
            txtPassword.Text != string.Empty))
        {
            // Creating SQL string. Using [] will prevent any erros
            // that might occur if any other names will be reserved words.
            string SQL =
                "INSERT INTO PersonalData([Type], [URL], [UserName], [Password]) " +
                "VALUES(@Type, @URL, @UserName, @Password)";

            InsertData(SQL);
        }
        else if (cmbType.SelectedIndex == 2 && 
            (txtSoftwareName.Text != string.Empty || 
            txtSerialCode.Text != string.Empty))
        {
            // Creating SQL string. Using [] will prevent any erros
            // that might occur if any other names will be reserved words.
            string SQL =
                "INSERT INTO PersonalData([Type], [SoftwareName], [SerialCode]) " +
                "VALUES(@Type, @SoftwareName, @SerialCode)";

            InsertData(SQL);
        }
        else
        {
            lblMessage.Text = "Please fill out all required fields!";
        }
    }
    else
    {
        lblMessage.Text = "Please select a type first!";
    }
}

Answer 1

您确定要或潜在字段而不是它们吗？例如，

else if (cmbType.SelectedIndex == 1 && 
    (txtURL.Text != string.Empty && 
    txtUserName.Text != string.Empty && 
    txtPassword.Text != string.Empty))

仅当 url、用户名和密码有值时才允许您插入数据 - 使用 or 时，在调用插入之前只需要填写其中一个值，这意味着您可以有一个有效的 url 但没有输入密码和用户名。