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Firstly, don't do it like that! Never concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Always use Parameterized queries instead.
When you concatenate strings, you cause problems because SQL receives commands like:
SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood' The quote the user added terminates the string as far as SQL is concerned and you get problems. But it could be worse. If I come along and type this instead: "x';DROP TABLE MyTable;--" Then SQL receives a very different command:
SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable; Which SQL sees as three separate commands:
SELECT * FROM MyTable WHERE StreetAddress = 'x'; A perfectly valid SELECT
DROP TABLE MyTable; A perfectly valid "delete the table" command
And everything else is a comment.
So it does: selects any matching rows, deletes the table from the DB, and ignores anything else.
So ALWAYS use parameterized queries! Or be prepared to restore your DB from backup frequently. You do take backups regularly, don't you?
Secondly, if I do much what you have there, it works fine:
listView1.Items.Clear();
listView1.Items.Add("aaa");
listView1.Items.Add("bbb");
listView1.Items.Add("acc");
listView1.Items.Add("ddd");
int itemCount = 0;
foreach (ListViewItem item in listView1.Items)
{
if ((itemCount++ & 1) == 0) item.BackColor = Color.Red;
}
So start by checking with the debugger exactly what is happening - at a guess, you have no items loaded into your ListView but without being able to run your code through the debugger and with your data available, we can't tell.
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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佳能相机怎么得到焦距,[How to get the focal length of Canon camera]
int focallength = MainCamera.GetInt32Setting(PropertyID.FocalLength);
返回错误属性不可用 [Return error attribute is not available]
[Google translate]
modified 13-Mar-19 2:51am.
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This is an English language site, and we can only respond to questions in that language. Please use Google Translate (if available in China, I don't know what your government allows you behind the Great Firewall).
I have modified your question.
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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The focal length isn't a property of the camera so you can't retrieve it - it's embedded in the image instead. Have a look at Canon EDSDK Tutorial in C#[^] to see how to get this.
This space for rent
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First of all, thank you for your answer. I looked at the link you gave me, used the demo inside, and returned the error not supported.I hope you can help me Solve the problem。
The code is as follows:
ErrorCode err;
IntPtr inStream;
err = CanonSDK.EdsCreateFileStream(filename, FileCreateDisposition.OpenExisting, FileAccess.Read, out inStream);
IntPtr imgRef;
err = CanonSDK.EdsCreateImageRef(inStream, out imgRef);
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how to add multiple drop down in excel file. suppose i have n number of questions and for each question can have different number of answers. So i want to create drop down for answers
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Does this have anything to do with C#? If so please add the details to your question.
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yes, using c# i am trying to create excel file. suppose i am creating question paper, which can have different questions and each question will have set of different answers. so for one set of answers i want drop down
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Is it enough methods for capture and report JavaScript errors on web page on computer and mobile devices?
window.onerror = function (msg, url, lineNo, columnNo, error) {
return true;
};
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Wrong forum - this is for C#, as it says at the top of the page...
Try here: JavaScript Discussion Boards[^]
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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What results do you think following code produces:
SizeF size = new SizeF(100.12f, 50.34f);
string result1 = Convert.ToString(size, CultureInfo.InvariantCulture);
string result2 = Convert.ToString(size, CultureInfo.GetCultureInfo("en-US"));
string result3 = size.ToString();
string result4 = FormattableString.Invariant($"{size}"); {Width=100.12, Height=50.34} , of course!?
But, alas, the result is always:
{Width=100,12, Height=50,34} with a decimal comma instead of a decimal point.
As a side note: "{" + string.Format(CultureInfo.InvariantCulture, "Width={0},Height={1}", size.Width, size.Height) + "}" returns the expected result.
That happens on my Windows 7 machine with a German OS.
Now I am a little confused...
I know that there's a SizeFConverter , but that would make things too complicated. I have a function which receives an object , converts that to a string and transfers the string to a different machine where the value should be parsed to a SizeF again.
(This post could also fit into the "Weird and Wonderful" category...
Oh sanctissimi Wilhelmus, Theodorus, et Fredericus!
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Convert.ToString doesn't have a specific overload that takes a SizeF, so it goes to the default Object version.
SizeF does not support IConvertable or IFormattable, so Convert.ToString doesn't really know what to do with it!
So it ends up just calling value.ToString which uses the default formatting for the machine and ignores the format you provided.
See the reference source and you'll see what I mean: Reference Source[^]
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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modified 11-Mar-19 8:29am.
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Thanks - so this is a good fit for the Weird and Wonderful!
Oh sanctissimi Wilhelmus, Theodorus, et Fredericus!
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You're welcome!
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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Useful ? ^]
if the problem is transmitting the float value independently of local culture settings, serialization to binary, xml,json >?
cheers, Bill
«Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information?» T. S. Elliot
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At the moment I have Visual Studio 2012 and Visual Studio 2015 installed on my computer.
I wanted to know if there is any reason I should keep these older versions on my computer as I want to install Visual Studio 2017; I have a limited amount of space on the C drive.
Am I likely to loose the code I have written? Is older code backward compatible?
Is it possible to install Visual Studio on a different hard drive with more space as my C drive is a
SSD drive with less space than my other hard drives.
Brian
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I have 2013, 2015, and 2017 on mine, and every project written in an earlier version has opened OK in later ones - so in theory you should be OK.
But ... two things:
1) VS2017 is a little flaky, especially compared to VS2013 - I've had it crash out and had to reinstall to fix the problems a couple of times. This is why I'm still doing the bulk of my work on 2013 - it wastes far, far too much time fixing the IDE! Not everybody is getting these problems however, so you may be lucky.
2) I'd strongly recommend that VS is installed on your SSD, not a HDD - the performance improvement is considerable (particularly with 2017, where the boot speed alone is significantly slower than 2013)
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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Thanks for the advice Griff.
I've heard of this happening to some updated program.
Out of interest what operating system do you use?
Brian
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Win10 V1803 Build 17134.590
The latest problem was that it would lock up when you tried to open any .CS file, A "repair install" (which is a reinstall under a new name) solved the problem, but threw away all my settings, templates, ...
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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I just wondered as it might be related to Windows 10. I use Windows 8.1
Still not good when it makes you feel frustrated and causes you more work.
If there is not many extra features or improvements then perhaps it's better to stay with the 2015 version like you say. I wonder if there are updates for Visual Studio 2017?
Brian
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Yes - but my version is up to date!
Microsoft is not fond of fixing bugs ...
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
AntiTwitter: @DalekDave is now a follower!
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Hi,
I want to get a copy of the line in foreach brackets. But since the copyline is the reference type, the line is also changing.
foreach ( var line in Lines)
{
var copyline= new LineTable();
copyline = line;
copyline.Id = 0;
copyline.InvoiceHeaderId = newHeaderId;
var lineResponse = _service.InsertLine(copyline);
if (lineResponse.Success)
{
line.UpdatedTime = DateTime.Now();
}
Already below that lines return value is true
System.Object.ReferenceEquals(line, copyline) return value of this code
Thanks for your answers
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