numericupdown reset to 100 automatically - c#

I have a numericupdown in my form and set its maximum value to 2000 although whenever i type a number bigger than 100 in and leave it the value reset to 100 automatically? I try this code to correct that but the behaviour doesn't correct.
private void answer_Enter(object sender, EventArgs e)
{
// Select the whole answer in the NumericUpDown control.
NumericUpDown answerBox = sender as NumericUpDown;
if (answerBox != null)
{
int lengthOfAnswer = answerBox.Value.ToString().Length;
answerBox.Select(0, lengthOfAnswer);
}
}

This code selects all text in the spin box of NumericUpDown control. Why? Because when you use Tab to navigate through controls to NumericUpDown, text will not be selected and input will start in first position. So, if you already have value 5 and type 6, then you will get 65. If all text will be selected, then selected value 5 will be replaces with new value 6.
Resetting value to max value is a default NumericUpDown control behavior. If entered number exceeds allowed maximum, then when you leave NumericUpDown control it's value will be replaces with allowed maximum.
Keep in mind, that actual value of NumericUpDown changed only when you leave control or use arrow keys to change value. When you type in text, value will not change until focus leaves spin box.
Verify to which control you have set Maximum value
NumericUpDown changes his value automatically only if entered value exceeds Maximum or Minimum value of that particular instance. So, it's obvious that your control has Maximum set to 100. Possibly you changed maximum value of some other control.

I haven't done a full analysis of this but I had similar problem when using this code:
<wf:NumericUpDown x:Name="NumericKernalSize" Width="50" Height="22" Visible="True" ValueChanged="NumericKernalSize_ValueChanged" BorderStyle="FixedSingle" Value="201" Minimum="0" Maximum="1000" />
What was happening was that the value = 201 seemed to be exceeding the default maximum of 100 before the maximum value was set to the desired max of 1000.
If you set the maximum before the value, the problem doesn't arise e.g. the following worked for me:-
<wf:NumericUpDown x:Name="NumericKernalSize" Width="50" Height="22" Visible="True" ValueChanged="NumericKernalSize_ValueChanged" BorderStyle="FixedSingle" Minimum="0" Maximum="1000" Value="201"/>
Hope this is of help to someone as it is tricky to catch this problem...
Cheers...

Related

NumericUpDown rejects value

I've got issues with NumericUpDown control. When I try to input a value, the control seems to reject it, despite the value being well withing Minimum and Maximum.
numericField.Hexadecimal = true
numericField.Minimum = 0;
numericField.Maximum = decimal.MaxValue;
Now, when I input FFFFFFF, it works fine. But adding another F will make the control automatically change the value to 0 upon losing focus.
What might be the reason?

How to look for a specific amount of digits within texbox textChanged event in C#?

In my Windows Form Application, I want to implement a feature where the user has to fill in the serial number of a product that is when matched with any product in the database, the product must appear in a grid. I want to do so using textbox textChanged event.
I am confused in figuring out that either I must prevent firing the textChanged event before the textbox value matches any value in the database. Is there any way to make the textbox expect a specific amount of text or number (my serial numbers are going to be fixed length - like 10001, 10002, 10003) before running the remaining code for showing product in the grid?
You can use TextLength property of the TextBox to get length of text. For example:
private void textBox1_TextChanged(object sender, EventArgs e)
{
if (textBox1.TextLength < 5)
return;
//Send query to database
}
Note: As it's also mentioned by Jimi in the comments, it's good idea to set MaxLength of TextBox to prevent entering more text.
Consider the use of a [MaskedTextBox][1]. A MaskedTextBox is similar to a standard TextBox, except you define the format of the input text. This can be anything, letters, numbers, dashes, etc.
In your case you accept only input of five digits.
Use the windows forms designer to add a MaskedTextBox, or add one yourself:
this.maskedTextBox1 = new System.Windows.Forms.MaskedTextBox();
this.maskedTextBox1.Location = ...
this.maskedTextBox1.Size = ...
// etc. Advise: let forms designer do this
// accept only input of five digits:
this.Mask = "00000";
The operator sees an indication of the length of the requested input. It is impossible for the operator to type a non-digit. Event when all five digits are entered, but also while typing (TextChanged), so if desired you can implement autocompletion. You can even get notified if operator presses one invalid key, so you can inform the operator about the error

when hitting enter in text box the value disappearing

I wish to accept maximum two digits to my text box I used this code.
if(textbox1.textlength==1)
{
this.selectNextcontrol((control)sender,true,true,true,true);
}
now the problem is that the text box also accept single value like 6, it is accepting but when I hit enter after placing 6 the value disappearing.
You can set maximum length property of textbox to 2.

Invalid TextBox values gets reset by ComboBox's DataBinding

Situation: A C# Windows Forms application with a TextBox and a ComboBox. AutoValidate is set to EnableAllowFocusChange.
The TextBox represents and is shown as a percentage value e.g. "10 %" which is stored as an int. Both input controls are data bound, the TextBox with a parsing and formatting ConvertEventHandler as well as a Validating CancelEventHandler.
When entering an invalid input like "abc" and leaving the control: My Validation is performed and fails (e.Cancel = true, ErrorProvider ..). And my parsing fails (e.Value stays "abc").
Problem: When I now change the value of the ComboBox and leave it (lost focus/perform validation) or do a ValidateChildren, my format function is called with the last valid percentage value and the wrong input is lost.
Stacktrace: The problem is triggered by a ReportPropertyChanged of the ComboBox and leads to Binding.PushData, FormatObject and OnFormat -> Which calls my format function with the original value.
I want my TextBox to stay invalid and no magical reset. What can I do to prevent a value reset? Or what did I do wrong?
Thanks!

C# /windows forms: linking trackbar and textfield with a factor

linking a trackbar and a textfield is very easy in windows forms.
it is like this:
textBox.DataBindings.Add("Text", trackBar, "Value");
the problem is, that trackbars only allow for integer values but i want to have floating point values.
so i usually just divide the value by 100, since on the trackbar the value is not directly visible to the user.
but in the textbox it is.
so is it possible to link these two with a factor of 100?
thanks!
The line of code you have adds a Binding object to the text box's DataBindings collection.
The Binding class has events called Format and Parse, which you can use to perform the division (the Format event takes a value from the trackbar and formats it for the text box) and the multiplication (the Parse event takes a value from the text box and scales it for the trackbar).
You can use intermediate variables like below:
public double v{set;get;}
public int v100
{
set { v = value / 100D; }
get { return (int)(v* 100D); }
}
and blind them with Controls.
trackBar.DataBindings.Add(new Binding("Value", PtParams, "v100"));
textBox.DataBindings.Add(new Binding("Text", PtParams, "v"));

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