If I do this:
string path = "\\myServer\myFile.txt"
I get a compilation error. So I do this:
string path = #"\\myServer\myFile.txt"
Altought the output of path in QUICK WATCH of Visual Studio is:
\\\\myServer\myFile.txt
Is there any clean way to avoid the problem of this 4 backslashes?
Although the output of path is:
\\\\myServer\myFile.txt
No, it's not. The value you might see in the debugger would be
\\\\myServer\\myFile.txt
which is just the debugger escaping the value for you.
The value of the string has a double backslash at the start, and a single backslash in the middle. For example:
Console.WriteLine(#"\\myServer\myFile.txt");
will print
\\myServer\myFile.txt
It's important to differentiate the actual content of the string, and some format seen in the debugger.
If you want to express the same string in code without using a verbatim string literal (that's the form starting with #) you can just escape each backslash:
string path = "\\\\myServer\\myFile.txt";
Again, the actual value there only has a total of three backslashes. For example:
string path1 = "\\\\myServer\\myFile.txt";
string path2 = #"\\myServer\myFile.txt";
Console.WriteLine(path1 == path2); // true
They're different literals representing the same string content.
string path = #"\\" will not create a string with 4 backslashes. It might look like that in the debugger, but try to Debug.WriteLine() it: there's only 2.
No, you have the choise between
string test = #"\\myServer\myFile.txt";
or
string test = "\\\\myServer\\myFile.txt";
Both contains \\myServer\myFile.txt
Related
I'm completely a junior here. I have tried something like
save a path and file string in a file like:
c:\aaa\bbb\text.txt
then I need to read again as path but I get c:\aaa\bbb\text.txt from streamreader, but I need c:\\\aaa\\\bbb\\\text.txt
Can anyone help me?
I think you might be confusing string literals with a string.
Say I write var myString = "\\" or var myString = #"\", this will show in the debugger as \\, because the debugger will format it as a literal. But if print it to the console, a file, or press the magnifying glass next to the string in the debugger, it will be shown as \, because that is the actual string value. See also verbatim string literal
So, if you do myStreamWriter.Write("c:\\aaa\\bbb\\text.txt");, you will be actually saving the string c:\aaa\bbb\text.txt, and that is also the string that will be read back.
However I fail to understand why you would want three slashes, I can only assume the OP thinks the escaping is done multiple times.
In order to be able to read a file in asp.net, the file path must be written in this:
1.
C:\\yung\\Desktop
returns
however, the string that the fileUpload get returns is
2.
C:\yung\Desktop
After reading the comments i have this code:
string FilePath = FileUploadPublicInfo.PostedFile.FileName;
System.IO.StreamReader file = new System.IO.StreamReader(FilePath);
string line = File.ReadLines(FilePath.ToString()).Skip(4).ToString();
TextBox1.Text = line.ToString();
But now its giving this error:
System.Linq.Enumerable+<SkipIterator>d__30`1[System.String]
How to solve this problem?
Thank you.
I'm not so sure I understand the question, but I think you are looking for string.Replace:
string DoubleSlash(string singleSlash)
{
return singleSlash.Replace(#"\", #"\\");
}
The reason backslashes disappear is that C# compiler treats slashes in string literals as a special "escape" character. Because of this treatment, backslash needs to be encoded as two slashes in a regular string literal.
C# offers two ways of inserting backslashes the way you need:
Use verbatim literals - prefix it with "at" sign, i.e. #"C:\\yung\\Desktop", or
Double each slash - put two slashes for each slash in the result: C:\\\\yung\\\\Desktop
Ok, i have manage to solve this problem, turns out it was not reading anything.
This is the code that i finally get:
This is to retrieve the File's path, using this, would give the file path will double slash, so there is not a need for Replace(#"\",#"\")
string FilePath = FileUploadPublicInfo.PostedFile.FileName;
Then read the specified file
System.IO.StreamReader file = new System.IO.StreamReader(FilePath);
If you know which line you specifically want, this retrieves the 5th line
string line = File.ReadLines(FilePath.ToString()).Skip(4).First().ToString();
Thank you so much for your help...
I need to send the value I receive from the model with this link, the proposalName field must be in quotes.How can I do it?
Here is my service url.
string path = string.Format("{ProposalId:{proposalId},ProposalName:{"proposalName"},VendorId:{vendorId}}",
Uri.EscapeDataString(proposalId.ToString()),
Uri.EscapeDataString(proposalName),
Uri.EscapeDataString(vendorId.ToString()));
You can simply put quotes around by escaping the quotes, like this -
string path = string.Format("{{0},ProposalName:\"{1}\",VendorId:{2}}",
Uri.EscapeDataString(proposalId.ToString()),
Uri.EscapeDataString(proposalName),
Uri.EscapeDataString(vendorId.ToString()));
As per your updated question, if you need to pass double quotes in URL, you need to encode it to %22
You can also use URI which allows a lot of flexibility with urls. For example -
Uri myUri = new Uri("http://google.com/search?hl=en&q=\"query with quotes\"");
Going with your example - Replace EscapeDataString with Uri.EscapeUriString. It will escape the chracter to form a valid URL. " will get replaced by %22
Some suggestions here and here-
Your problem exactlly in the {"1"} part. The double quotation mark " should be outside the {}, not inside them.
here is the fixed code.
string path = string.Format("{{0},ProposalName:\"{1}\",VendorId:{2}}",
Uri.EscapeDataString(proposalId.ToString()),
Uri.EscapeDataString(proposalName),
Uri.EscapeDataString(vendorId.ToString()));
or
string path = string.Format(#"{{0},ProposalName:""{1}"",VendorId:{2}}",
Uri.EscapeDataString(proposalId.ToString()),
Uri.EscapeDataString(proposalName),
Uri.EscapeDataString(vendorId.ToString()));
and if you are using C# 6 then you can write it as following
string path = $"{Uri.EscapeDataString(proposalId.ToString())},ProposalName:\"{Uri.EscapeDataString(proposalName)}\",VendorId:{Uri.EscapeDataString(vendorId.ToString())}";
This might do the trick for you
\"{1}\"
instead of
{"1"}
because you can put \ symbol to indicate escape sequence followed by a reserved characters
So
string.Format("{{{0},ProposalName:\"{1}\",VendorId:{2}}}",
I think escaping the quotes and placing them outside the brackets will work:
"{{0},ProposalName:\"{1}\",VendorId:{2}}"
Depending on the C# version, you can also do it like this, which I often think is an easier and cleaner way to do it:
string path = $"{proposalId},ProposalName:\"{proposalName}\",VendorId:{vendorId}";
You have two problems:
Wrong quotation (should be outside the braces {...} and escaped)
Incorrect { and } escape: {{ means just a single '{' in a formatting string
Should be
string path = string.Format("{{{0},ProposalName:\"{1}\",VendorId:{2}}}",
please, notice
escaped quotations \" which are outside {1}
tripled curly braces{{{ and }}}
Edit: in your edited question you have the same errors:
string format =
"http://mobile.teklifdosyam.com/VendorReport/GetListProposalService?&page=1&start=0&limit=10&filter=" +
"{{ProposalId:{0},ProposalName:\"{1}\",VendorId:{2}}}";
string path = string.Format(format,
Uri.EscapeDataString(proposalId.ToString()),
Uri.EscapeDataString(proposalName),
Uri.EscapeDataString(vendorId.ToString()));
please, notice escaped quotations \" which are outside the {1}, double '{{' and tripled '}}}'. When formatting you have to use numbers as place holders: so {"proposalName"} must be changed into {0}
I have :
string Combine = Path.Combine("shree\\", "file1.txt");
string Combine1 = Path.Combine("shree", "file1.txt");
Both gives same result :
shree\file1.txt
What actually happen behind Path.Combine?Which is the best coding practice to do this.please clear my vision.Thanks.
If the first path (shree or shree\\) does not end with a valid separator character (e.g. DirectorySeparatorChar) it is appended to the path before concatenation.
So
string path1 = "shree";
string path2 = "file1.txt";
string combined = Path.Combine(path1, path2);
will result in "shree\file1.txt", while
string path1 = "shree\\";
already contains a valid separator character, so the Combine method will not add another one.
Here you typed two slashes in the string variable (path1). The first one just acts as an escape character for the second one. This is the same as using a verbatim string literal.
string path1 = #"shree\";
More information on the Combine method can be found on MSDN:
http://msdn.microsoft.com/en-us/library/fyy7a5kt.aspx
Use the second one. This way you don't care about what is the directory separator.
What actually happen behind Path.Combine?
It builds you a path... so it's doesn't matter what of those two you will use. but those \\ are redundant.
If you're interested with micro optimization, create a test which of the two is faster.
A string variable str contains the following somewhere inside it: se\">
I'm trying to find the beginning of it using:
str.IndexOf("se\\\">")
which returns -1
Why isn't it finding the substring?
Note: due to editing the snippet showed 5x \ for a while, the original had 3 in a row.
Your code is in fact searching for 'se\\">'. When searching for strings including backslashes I usually find it easier to use verbatim strings:
str.IndexOf(#"se\"">")
In this case you also have a quote in the search string, so there is still some escaping, but I personally find it easier to read.
Update: my answer was based on the edit that introduced extra slashes in the parameter to the IndexOf call. Based on current version, I would place my bet on str simply not containing the expected character sequence.
Update 2:
Based on the comments on this answer, it seems to be some confusion regarding the role of the '\' character in the strings. When you inspect a string in the Visual Studio debugger, it will be displayed with escaping characters.
So, if you have a text box and type 'c:\' in it, inspecting the Text property in the debugger will show 'c:\\'. An extra backslash is added for escaping purposes. The actual string content is still 'c:\' (which can be verified by checking the Length property of the string; it will be 3, not 4).
If we take the following string (taken from the comment below)
" '<em
class=\"correct_response\">a
night light</em><br
/><br /><table
width=\"100%\"><tr><td
class=\"right\">Ingrid</td></tr></table>')"
...the \" sequences are simply escaped quotation marks; the backslashes are not part of the string content. So, you are in fact looking for 'se">', not 'se\">'. Either of these will work:
str.IndexOf(#"se"">"); // verbatim string; escape quotation mark by doubling it
str.IndexOf("se\">"); // regular string; escape quotation mark using backslash
This works:
string str = "<case\\\">";
int i = str.IndexOf("se\\\">"); // i = 3
Maybe you're not correctly escaping one of the two strings?
EDIT there's an extra couple of \ in the string you are searching for.
Maybe the str variable does not actually contain the backslash.
It may be just that when you mouse over the variable while debugging, the debugger tooltip will show the escape character.
e.g. If you put a breakpoint after this assignment
string str = "123\"456";
the tooltip will show 123\"456 and not 123"456.
However if you click on the visualize icon, you will get the correct string 123"456
Following code:
public static void RunSnippet()
{
string s = File.ReadAllText (#"D:\txt.txt");
Console.WriteLine (s);
int i = s.IndexOf("se\\\">");
Console.WriteLine (i);
}
Gives following output:
some text before se\"> some text after
17
Seems like working to me...
TextBox2.Text = TextBox1.Text.IndexOf("se\"">")
seems to work in VB.
DoubleQuotes within a string need to be specified like "" Also consider using verbatim strings - So an example would be
var source = #"abdefghise\"">jklmon";
Console.WriteLine(source.IndexOf(#"se\"">")); // returns 8
If you are looking for se\">
then
str.IndexOf(#"se\"">")
is less error-prone. Note the double "" and single \
Edit, after the comment: it seems like the string may contain ecaping itself, in which case in se\"> the \" was an escaped quote, so the literal text is simply se"> and the string to use is Indexof("se\">")