How to convert innertext? - c#

Hello I retrieve data from webbrowser control by use getelementbyid.
var element = webbrowser.document.getelementbyid(something);
i have a problem is cant convert to double which can convert to string.
i want to know about convertion to be double. it's can possible?
i tried already but ...
Input string was not in a correct format.
What's wrong?

Use value of html element.
Try this,
double d = double.Parse(webbrowser.document.getelementbyid(something).value);

I assume you're trying to do something like this;
string innerHtml = webbrowser.Document.GetElementById(something).InnerHtml;
double value;
if(Double.TryParse(innerHtml, out value))
{
// value is now populated
};

You could use
double d;
string element = webbrowser.document.getelementbyid(something).Value;
if (Double.TryParse(element, out d))
{
// Conversion succesful: in d you find your number
}
Take a look at Double.TryParse syntax.

After retrieving the value in string form, you should use Double.TryParse to parse it as a double, e.g.:
double number;
if (Double.TryParse(webbrowser.document.getelementbyid(something), out number))
{
// ... do something useful with 'number' ...
}

Related

How to convert reader.Read string to currency format in c#?

I built the below code, trying to convert reader[BalanceAmt] to a currency, i.e. $23,456.78. I can't seem to get it to work. It's still returning "23456.782" Any ideas?
while (reader.Read())
{
string MyNum = reader["BalanceAmt"].ToString();
String.Format("{0:#,###0}", MyNum);
BalanceBox.Text = (MyNum);
}
If reader["BalanceAmt"] returns a string then to get your numeric formatting to work, you need to convert it into a number before converting it to currency - i.e.
var myNum = Convert.ToDecimal(reader["BalanceAmt"]);
BalanceBox.Text = myNum.ToString("C");
Note the "C" currency format specifier argument passed into the decimal.ToString method - see MSDN Decimal.ToString Method Documentation.
The Convert.ToDecimal method will throw an exception if reader["BalanceAmt"] contains anything that Convert.ToDecimal is unable to cope with (non-numeric characters).
You might want to put a try..catch around this, or if you don't want an exception to be thrown, use Decimal.TryParse inside an if check:
var balanceAmt = reader["BalanceAmt"];
if (decimal.TryParse(balanceAmt, out var myNum))
{
BalanceBox.Text = myNum.ToString("C");
}
while (reader.Read())
{
BalanceBox.Text = reader["BalanceAmt"].ToString("c");
}
In your code String.Format("{0:#,###0}", MyNum); MyNum never changes...only formatted.
Please use this:
BalanceBox.Text = String.Format("{0:#,###0}", Convert.ToDouble(MyNum));

Convert double to string, keep format - C#

Hi all. I have a double number (Ex: 0.000006). I want convert it to string type. But result is "6E-06". I dont want it, i want 0.000006".Thanks you so much
double a = 0.000006;
string resultString = a.toString();
I don't know many number after "." character
It's simple that if you want to show a number as exactly as what it looks, we can cast it to decimal and use the default ToString() like this:
var s = ((decimal)yourNumber).ToString();
//if yourNumber = 0.00000000000000000000000006
//just append the M after it:
var s = (0.00000000000000000000000006M).ToString();
Please check this article and find the format which suits your needs: http://www.csharp-examples.net/string-format-double/
Looks like this one is good enough:
String.Format("{0:0.00}", 123.4567);
Use String.Format() with the format specifier.
double a = 0.000006;
string formatted = String.Format("{0:F6}", a);
Try with the Roundtrip 'R' format specifier:
double a = 0.000006;
string resultString = a.ToString("R");
Double Rate_USD = Convert.ToDouble(txtRateUsd.Text);
string Rate_USD = txtRateUsd.Text;

c# Convert.ToDouble format exception error

I'm trying to convert this string to double
Convert.ToDouble("1.12");
and this is the output
System.FormatException was unhandled.
Should I do something like this?
public static double ConvertToDouble(string ParseVersion)
{
double NewestVersion;
try
{
NewestVersion = Convert.ToDouble(ParseVersion);
}
catch
{
ParseVersion = ParseVersion.Replace('.', ',');
NewestVersion = Convert.ToDouble(ParseVersion);
}
return NewestVersion;
}
ConvertToDouble("1.12");
Or is there an easier solution?
double.Parse will use the current culture by default. It sounds like you want the invariant culture:
double d = double.Parse("1.12", CultureInfo.InvariantCulture);
EDIT: Just to be clear, obviously you shouldn't use this if you're trying to parse text entered by a user in a different culture. This is for use when you've received data in the invariant culture (as most machine-to-machine data text-based formats are) and want to enforce that when parsing.
You don't have to replace . to ,.. however a better way is to use the .net TryParse method like:
double d;
if (double.TryParse("your string data", out d)
{
Console.WriteLine(d);
}
Edit: Also note that by replacing . by , you are getting a wrong results, for instance 1.12:
double d = double.Parse(1.12);//d will equals to 1.12
double d = double.Parse(1,12);//d will equals to 112.0
Convert.ToDouble uses Double.Parse internally. If you are unsure of the culture context, you should use an overload of Double.Parse precising the culture:
double d = double.Parse("1.12", CultureInfo.InvariantCulture);
Keep in mind, this problem can depend on where the input string comes from. If it is read from a database as an object, you might solve your problem by keeping it as an object and using Convert.ToDouble() as follows:
public double Double_fromObject(object obj)
{
double dNum = 0.0;
if (obj.ToString() != string.Empty) // the Convert fails when ""
{
try
{
dNum = Convert.ToDouble(obj);
}
catch (SystemException sex)
{
// this class's error string
LastError = sex.Message;
}
}
return (dNum);
}

C# > Convert string to double when input=""

I would like to convert a string to double (very basic question isn't it ?)
string input = "45.00000";
double numberd = Double.Parse(input, CultureInfo.InvariantCulture);
=> my code works and I am very happy.
However I may have the following
string input = "";
double numberd = Double.Parse(input, CultureInfo.InvariantCulture);
In this case my code does not work and I get a Exception error ;(
I wonder how I can manage such situation. Ideally when I get this I would like to have my variable numberd equal to null.
Can anyone help me ?
Thx
Microsoft recommends using the Tester-Doer pattern as follows:
string input = "";
double numberd;
if( Double.TryParse(input, out numberd) )
{
// number parsed!
}
Use a Double for parsing, but a Double? for storing the value, perhaps?
Double number;
string input = ""; // just for demo purpose, naturally ;o)
Double? nullableNumber =
Double.TryParse(input, NumberStyles.Any, CultureInfo.InvariantCulture, out number)
? (Double?)number
: null;
// use nullableNumber
Primitive types like double cannot be null. You can have a nullable version with double? but, Double.Parse does not return a double? (just a plain double).
You could use Double.TryParse and check the return condition and set a double? to null accordingly if that would suit better.
Why not just catch the exception and set your variable?
double numberd;
try {
numberd = Double.Parse(input, CultureInfo.InvariantCulture);
} catch (System.FormatException e)
numberd = 0.0;
}
Alternatively, you can use Double.TryParse
Add an if statement comparing strings or surround with try/catch block.
Assuming you aren't worried about other invalid values besides empty strings, here's a simple one-liner:
Double? numberd = (input.Length == 0) ? null : (Double?)Double.Parse(input, CultureInfo.InvariantCulture);
mzabsky was on the right path, however his solution won't build and you shouldn't hard-code empty string - it's better to check the length of a string.
How about
Double? numberd = String.IsNullOrEmpty(str) ? null : Double.Parse(str)
In my application, I am parsing CSV files and I want these empty strings to be zero so I return 0.0 instead of null and it's all good.
5 more

How to Parse a String to Double

Here is my string
20.0e-6
I'm parsing it like
String Ans=Double.Parse("20.0e-6")
Now i'm getting the result like 2E-05
But the required output should be like
0.00002
How to get this?
The result of Double.Parse is a Double, not a string. You need to output a string from the double, using ToString.
You should also use an overload of Double.Parse that has a NumberStyles parameter. Using the Float value allows exponent notation:
string Ans=Double.Parse("20.0e-6", NumberStyles.Float).ToString("0.#####");
If you don't want to risk exceptions (InvlidCastException for example), you can use TryParse:
Double res;
if (Double.TryParse("20.0e-6", NumberStyles.Float,
CultureInfo.InvariantCulture ,res))
{
string Ans = res.ToString("0.#####");
}
It's the same number, but if you want to modify the output of the string, use a formatter on your ToString()
http://msdn.microsoft.com/en-us/library/dwhawy9k.aspx
So
String Ans=Double.Parse("20.0e-6").ToString("0.0####")
One way to get the result you want is to use String.Format as follow:
double x = 20.0e-6;
string y = string.Format("{0:0.######}",x);
Console.WriteLine(y);
Given your example, this outputs the value 0.00002
EDIT
I've just realised that this is actually the opposite of your question so in the aim of keeping the answer useful i'll add the following:
Given a string, you can parse as double and then apply the same logic as above. Probably not the most elegant solution however it offers another way to get the result you want.
string x = "20.0e-6";
var y = double.Parse(p);
Console.WriteLine(String.Format("{0:0.######}",y));

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