Develop Reference

Variable decimal formating in string interpolation

I have looked around for this, but I'm not sure it's possible with string interpolation (I'm using VS2015).
string sequenceNumber = $"{fieldValuePrefix.ToUpper()}{separator}{similarPrefixes + 1:D4}";
Is there any way to make D4 a variable ? Some say yes, some no. Apparently, VS2015 C#6.0 is able to do it.
This works, it will return a string like WMT-0021, depending on fieldValuePrefix (WMT), separator (-) and the value of similarPrefixes (20). But I'd like the "D4" part to be a method argument instead of hardcoded in there.
Any ideas ?

You can, but you have to use explicit ToString call like this:
string format = "D4";
string sequenceNumber =
$"{fieldValuePrefix.ToUpper()}{separator}{(similarPrefixes + 1).ToString(format)}";

How to concatenate two values into text box in c#?

I have two values, I want to cast these values into a text box. The way I tried is mentioned below
string time="00";
int Result ="02";
textresult.Text=result+' '+time;//first way error result
textresult.Text=(CAST(Result AS varchar(50))+' '+CAST(time AS varchar(50)))//second way..syntax error.
I need output as 02:00 format in text box. Please suggest a way to solve this????

Try this:-
string time = "00";
int Result = 02;
textresult.Text=Result.ToString("D2") + ":" + time;

Try below.
textresult.Text=string.Format("{0}:{1}",Result.ToString("D2"),time);
Your code reports syntax error because there is. It seems you are using C# like sql syntax!

This might help.
string time="00";
int Result =02;
textresult.Text = String.Format("{0}:{1}",Result.ToString("D2"),time);
Fiddle link

How to check if a MaskedTextBox is empty from a user input?

I'm using a MaskedTextBox, with the following short date Mask: "00/00/0000".
My problem is that I wanna know when the control is empty:
if (string.IsNullOrEmpty(maskedTextBox1.Text))
{
DataTable dt = function.ViewOrders(Functions.GetEid);
dataGridView2.DataSource = dt;
}
It's not working, when maskedTextBox1 looks empty (and I'm sure it is), the if statement doesn't detect that it is null or Empty.

You can simply use:
maskedTextBox1.MaskCompleted
Or
maskedTextBox1.MaskFull
properties to check if user has entered the complete mask input or not.

I know this is old but I would first remove the mask and then check the text like a normal textbox.
maskedTextBox.TextMaskFormat = MaskFormat.ExcludePromptAndLiterals;
//...Perform normal textbox validation

I just faced this problem. I Needed the Masked Value, but also needed send empty string if the user didn't introduced any data in one single step.
I discovered the property
MaskedTextProvider.ToDisplayString so I use the MaskedTextbox with:
maskedTextBox.TextMaskFormat = MaskFormat.ExcludePromptAndLiterals;
BUT I always read the text from:
maskedTextBox.MaskedTextProvider.ToDisplayString()
This way, if the user has not introduced text in the control Text property will be empty:
maskedTextBox.Text == string.Empty
And when you detect the string is not empty you can use the full text including literals for example:
DoSomething((maskedTextBox.Text == string.Empty) ? maskedTextBox.Text: maskedTextBox.MaskedTextProvider.ToDisplayString());
or
DoSomething((maskedTextBox.Text == string.Empty) ? string.Empty: maskedTextBox.MaskedTextProvider.ToDisplayString());

If you set the property maskedTextBox.TextMaskFormat = MaskFormat.ExcludePromptAndLiterals then the TypeValidationCompleted event validation will not work. To test if the short date maskedtextbox is empty you could just use:
if (maskedTextBox1.Text == " / /")
{
...;
}

Did you try trim.
if(string.IsNullOrEmpty(maskedTextBox.Text.Trim())

What logic are you trying to accomplish with the if statement? As it is right know, you are saying:
If the textbox is empty, set source of datagridview2 + to ViewOrder data. I'm not sure what your trying to do but I think you want the info to load if you have a date. to fix this all you have to do is add ! in the if statement which would make the if statement mean, if there is text in textbox then run code.
if( !(string.IsNullOrEmpty(maskedTextBox2.Text)))

In case of Telerik masked textbox which does not have MaskCompleted or MaskFull, a tricky solution would be this:
the mask always contain a charachter like this: "_" we check masked text box by this:
if (textbox1.Text.Contains("_"))
{
MessageBox.Show("Please enter the correct numbers!","Error",MessageBoxButtons.OK,MessageBoxIcon.Stop);
return;
}
if the text box is full, then it does not contain "_".

I believe the MaskedTextBox, (MTB), using the mask “00/00/0000” is an incorrect string to use for testing its emptiness. This is because the MTB is not like a normal textbox, and the short date mask must be used to determine its string value.
Let’s assume you have a MTB name mskDateOfBirth on your form. In order to test its emptiness, a statement like the following is needed
if (mskDateOfBirth.MaskedTextProvider.ToDisplayString() == "__/__/____")
{
// Do something when true
}
else
{
// Do something when false
}
I have tested this out using Visual Studio 2019 and it works fine. Hope this is helpful.

If the empty value is " / /", declare a constant for it:
const string EmptyDateInput = " / /";
And then later you can repeatedly use it to compare:
if (maskedTextBox1.Text == EmptyDateInput)
{
}

I test this concept and was success in in the following syntax
if( maskedtextbox_name.MaskkedTextProvider.ToDisplayString() == "__-__-____")
{
// Your function;
}

Adding two values from database together

How would i be able to add 2 parameter together?
i have this following code but it dont seem to work
balanceDB = readdata[("balance"+"overdraftLimit")].ToString();

balanceDB = (readdata["balance"] + readdata["overdraftlimit"]).ToString();
This is assuming that you will do the casts. If you don't have casts in your code you need to do something like:
balanceDB = (Convert.ToDouble(readdata["balance"].ToString()) + Convert.ToDouble(readdata["overdraftlimit"])).ToString();
Adjust to fit whatever data type is necessary for these two fields.

Considering that balanceDB is a string. Have you tried this:
balanceDB = readdata["balance"].ToString() + readdata["overdraftLimit"].ToString();

I assume you are trying to do this with a DataReader, right?
You will need to read in each column separately, and concat them together. The code below assumes you are working with strings. If they are integers, or some other type, you need to cast accordingly
balanceDB = readdata["balance"].ToString() + readdata["overdraftlimit"].ToString();

I assume that readdata is a DataTable/datareader and what you want is to add values of balance and overdraftLimit.
int balanceDB;
balanceDB = (Convert.ToInt32(readdata["balance"])+Convert.ToInt32(readdata["overdraftLimit"]));
Supposed the value of balance =1 and overdraftLimit=1 then balanceDB will be equals to 2
Or if you just need to concatenate the two strings:
string balanceDB;
balanceDB = readdata["balance"].ToString()+readdata["overdraftLimit"].ToString();
balanceDB will be equals to 11.
Regards

How to affect formatting of dynamically created label text in c#

I think this should be a pretty easy question to answer but I can't seem to figure it out.
I am adding text to labels from a sqldatasource in c#. All of that works, but I want to be able to format the text. I want to 1) be able to change the format to 0.00 (instead of a string of decimals) and I would also like to be able to add words before the text. I assume I need to somehow use the string.format command but can't figure out how to work it in. Any help would be greatly appreciated. Here's my code below:
DataView dvSql = (DataView)DeskSummary.Select(DataSourceSelectArguments.Empty);
foreach (DataRowView drvSql in dvSql)
{
Desk.Text = drvSql["Deskname"].ToString();
MarginLabel.Text = drvSql["margin"].ToString();
CurrentCI.Text = drvSql["comp_index_primarycomp"].ToString();
WalMartCurrentCI.Text = drvSql["comp_index_walmart"].ToString();
ForecastMargin.Text = drvSql["margin_forecast"].ToString();
WalMartForecastCI.Text = drvSql["comp_index_walmart_forecast"].ToString();
ForecastCI.Text = drvSql["comp_index_primarycomp_forecast"].ToString();
}

You can pass the format argument to the ToString() method like so:
MarginLabel.Text = drvSql["margin"].ToString("0.00");
However, as you said you wanted to prepend some text. Therefore, I recommend:
MarginLabel.Text = String.Format("Prepended text {0:0.00}", drvSql["margin"]);
Note: I just picked one of your labels; I'm not sure which ones get special formatting treatment.

use the
string.Format("This is a before text {"0"},your param)
// you can add as many variables and {""} string literals as you need just make sure that you separate the variables with a ","

Here is the code
string stringNumber = "5123.34214513";
decimal decimalNumber = Decimal.Parse(stringNumber);
string output = String.Format("Your text: {0:0.00}", decimalNumber);
Console.WriteLine(output); //Your text: 5123.34
This works if the column is of type string

String.Format() will do what you need for prepending/appending text values,
string.Format("prepend text {"0"} append text", paramString)
But if you want to actually format the value you are getting back from SQL, then you would need to use String.Format() on that value as well as possibly some RegEx expressions and/or .ToUpperCase or .ToLowercase for your capitalization... something like.
var capitalizedString = paramString.subStr(0,1).ToUppercase + paramString.subStr(1, paramstring.Length);
string.Format("Prepended text {"0"} plus appended text", capitalizedString);