Hello my WinForm application has a textbox that will be used for a time value. I know how to load like the current time into the textbox, but say when a user enters a value, what is the best way to validate or format the number so I can attempt to Convert it to a TimeDate value?
Example:
User enters something like 800 should be able to be converted to 8:00am or 2354 should be 11:54pm. Also if they enter an invalid time, like 9cdf83 or something, I need to check that this value is convertable to a time. If not, throw a warning. Is there a way to display a system clock to choose the time from like the dateTimePicker?
For things like date and time which u want user to enter best is to use DateTimePicker bcoz n number of users will have n number of ideas to fill it. u can't go on checking each and every option.
Instead DateTimePicker will make user to enter through it only.
you can place the textbox and a label beside it specifying the format like 8:00 AM and for validating it you can use custom validation and use a suitable regular expression as required for the validator and attach it to textbox.
But For conversion I thing you will have to code and check its validity.
Related
I have a Textedit Control that I want to behave in a certain way:
When the Control has input focus, I want to only allow the input of positive whole Numbers (not zero). I achieve that by using Properties.Mask, which works fine.
When the Control does NOT have input focus, I want it to Display the entered number but with ",00" at the end.
So basically, while I enter something, I only see what I enter e.g. "17" but when the Control loses focus, I want it to show "17,00". So that I am only allowed to enter whole positive numbers but the Control will always add ",00" afterwards.
My understanding is that there are basically two different "modes": DisplayMode and EditMode.
EditMode = The Control has focus.
DisplayMode = The Control does not have focus.
In EditMode, I can type things into my Textedit Control. What I can and can not enter is determined by the Mask.
When I lose focus, it goes into DisplayMode. Here I cant type anything into the TextEdit but now the displayed text is not determined by the mask any more but by the Property "Properties.DisplayFormat". So to achieve my goal, I tried to set the DisplayFormat.FormatString to "0.00", so that it would always show two decimal places "x,00".
Somehow, this doesn't work as expected. The DisplayFormat doesn't seem to do anything and even in DisplayMode, the TextEdit still shows just the whole number without the decimal places.
I realize that I could use events to work around this problem but I think that's what DisplayFormat, EditFormat and Mask are for and I really don't want to handle multiple events for something that small.
Accodring to DevExpress Knowledge Base topic DisplayFormat is not working in unbound mode.
Problems with formatting occurs because an unbound text editor stores
a value as a string, therefore formatting cannot be applied.
If you use XtraEditors 3 or higher, you may wish to set the editor's
Mask.MaskType property to Numeric. In this case, the editor is forced
to handle the edit value as a number and, therefore, it can format it.
If you wish not to use the Numeric (or DateTime) mask, please use the
ParseEditValue event to convert a string to a number.
I can suggest you to use Numeric mask with n0 as edit mask:
To accomplish the above is fairly simple:
To only allow positive whole numbers, you need to set the MaskType to Numeric and use the EditMask ##########;. The number of # represents the possible number of didgets so ten times # means you can use a ten-digit number. (see nempoBu4's answer)
To show an additional ,00 when the control loses the focus, you simply need to set the DisplayFormat as FormatType = Numeric and FormatString = n2.
In my Content page I have 4 different TextBox's which is used to enter phone number - Mobile, Office Phone, Office Mobile & Other. I have RegularExpressionValidator for each.
I want to make sure atleast one of the above 4 textbox's has entered a value. I didn't find any example or article on net showing this situation. One way I think is in Submit button click, before Page.IsValid call, call a function that checks that one of the control has valid value. If the function returns false, show MessageBox. Is their any other way using Validators or so to comfirm that one textbox out of 4 has a valid value.
What can be the best way to achieve this ?
Any help is highly appreciated.
Thankss
You can create a Custom Validator in ASP.NET.
This post should help you out.
asp.net required field validator for at least one textbox contains text
Users of my application can enter values into TextBoxes. In some cases the values need to be restricted to a certain range, e.g. 0 to 1, or 1 to 50. In other cases they can only enter upto 13 or 20 characters depending.
Can I use Binding.StringFormat to enforce these ranges? If so,
what do I need to specify to restrict values to a certain character length?
what do I need to specify to restrict values to a certain range?
If not, what's the best way to implement this?
What you want is input validation.
For starters this tutorial on MSDN will help you, more information on IDataErrorInfo (preferred way) can be obtained here.
This question was already a topic on SO: WPF Data Binding and Validation Rules Best Practices
The Vaildation in WPF Code Project should give you a good start.
Also the related question WPF Validators like ASP.NET should assist.
You need to use Input mask, Check out this article WPF Maskable TextBox for Numeric Values
Based on this article in Events TextBox_PreviewTextInput and TextBoxPastingEventHandler you could check for a range.
The text box length property should solve
Textbox.maxlength= 10;
How to make that user can only input hour format in text box for example HH:MM?
Depending on strictness of requirements you may want to create a specific behaviour that will be attached to KeyDown event and disable keys other than currently accepted given format and current text input position in (HH:MM), you could even think of different ways to guarantee automatic : input by your behaviour if you want to be limited by textbox control for time input.
you can get some inspiration here I think
numeric only behaviour example
Look at Binding.StringFormat. It allows for conversion to DateTime or TimeSpan while specifying a certain string format to define how the user inputs the value, and how the value is displayed.
It sounds like you are looking for a masked text box.
You can fine one on codeplex here...
WPF Toolkit
EDIT.
There is also a datetimeupdown control. Which might be nearer to what you want.
I want that a user only enters numeric data into the textbox in a windows form. How can I achieve this?
The easiest way would be to use a MaskedTextBox (use the Mask property) or a NumericUpDown control. If you really need fine-grained control that these controls do not provide, handle the KeyPress and other appropriate events of the TextBox control as required.
EDIT: Clarified that KeyPress is not the only relevant event, as mentioned by ho1.
What do you want to happen when the user attempts to enter a non-numeric value? Does this matter before a data submission attempt? Without entering your code block every time a key is pressed, I think it'd be cleaner to just let the user enter non-numerics and validate either when the form is submitted and/or when the text box loses focus. Then if validation fails, notify the user of the strict numeric format. This would be less invasive to a user, rather than interrupting.
As for validation, just use either regular expressions or try to parse the text box's text as an integer.
Regular Expression
System.Text.RegularExpressions.Regex.IsMatch(e.KeyChar.ToString(), #"^\d$");
Integer Parse
int validNumbers = 0;
bool isValid = int.TryParse(myTextBox.Text, out validNumbers);
First it depends on what kind of numeric data you want to allow. (Integer, Double, ..., or something app-specific? Like an ISBN or something?)
Short:
The easiest way would be like Ani said, but if you need a more specific way, you should subcribe an matching Event. For Example TextBox.Validating, TextBox.OnLeave, TextBox.OnTextChange... depends on when you want to test the matching.
Than you can test in the Eventhandler whatever you want, even RegEx would be possible for complex alphanumeric data.
PS: You should really have a look at http://msdn.microsoft.com/en-us/library/system.windows.forms.control.validating.aspx