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Hi I am new to c# and learning a lot lately. My question relates to classes. Say I create a class then fill it with my parameters and a constructor, do I need a method for functionality in the class or do classes not always need functionality. Just a general question.
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Are you asking this more from a language-lawyer point of view (having no methods is of course allowed by the language) or more from a design point of view, eg how useful is a class with no methods?
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Properties are kinda like methods. A class could be nothing more than a data bag. He could use a struct instead, but why bother?
".45 ACP - because shooting twice is just silly" - JSOP, 2010
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You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
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When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013
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Depends on what you are storing in the struct, and what you are doing with it.
Using struct and class - what's that all about?[^] explains it, I think (even if it is blowing my own trumpet).
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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The only hard and fast rules as far as what to use are enforced by the compiler. Everything else are just guidelines. 
".45 ACP - because shooting twice is just silly" - JSOP, 2010
-
You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
-
When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013
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A class does not even need an (explicit) constructor. Any data members of such a class will be initialized with the default value for their type. If you make all the data members 'public', you may access them by name.
However, writing classes this way is IMO an abuse of the language. Just because it can be done does not mean that it should be done.
As usual, every rule has its exceptions; there are some cases when this is just what you need.
If you have an important point to make, don't try to be subtle or clever. Use a pile driver. Hit the point once. Then come back and hit it again. Then hit it a third time - a tremendous whack.
--Winston Churchill
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Classes don't always need methods. Suppose that you have a data model that represents a user.
public class Name
{
public string Name { get; set; }
public int Department { get; set; }
public DateTime BirthDate { get; set; }
}This model is perfectly fine. It's generally considered good practice to separate out the retrieving of the data from the model, so you might have a separate class that is responsible for retrieving the data and populating the name*. That might look something like this:
public class Users
{
private IEnumerable<User> users;
public IEnumerable<User> Users { get { return users; } }
public void LoadUsers()
{
users = new List<User>();
using (DataAccess dal = new DataAccess())
{
IDataReader reader = dal.GetValuesFromStoredProcedure("GetUsers");
while (reader.Read())
{
User user = new User();
dal.Populate(user.Name, "Name");
dal.Populate(user.Department, "Department");
dal.Populate(user.BirthDate, "DOB");
users.Add(user);
}
}
}
}A little bit of explanation about that last method before you get worried. DataAccess is the name of a class I have that allows me to do a lot of common SQL data operations - I prefer having my own version, rather than relying on things like Entity Framework. The methods you see being called in there are responsible for retrieving values from a stored procedure, then using that to populate a list of users.
*I meant to add this earlier. Even though the data model class doesn't visibly have methods because you have exposed properties here, the internal code that is created from this has methods because a property internally translates to separate get and set methods; so, Name becomes get_Name() and set_Name(string value) internally.
This space for rent
modified 11-Jan-17 6:07am.
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You don't need to create "methods" for your new class; though you will always have some by default because every class ultimately inherits from class "Object"; and "object" has a few built-in methods like ToString() and GetType().
"(I) am amazed to see myself here rather than there ... now rather than then".
― Blaise Pascal
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Hi all,
How to multiple tabs open and close click on buttons.
Actually i want to this scenario :
1.Dynamically add some tab items in browser [ Click on Add button ]
2.Dynamically close all browser tab items ,still open remaining single tab item.[ Click on Close button]
How its possible in Java Script or C#.
Thanks,
A.Aniruddhan
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Aniruddha.A wrote: 1.Dynamically add some tab items in browser
<a href="/path.html" target="_blank">Click me</a>
This code will open the content in a new tab. As for JavaScript, you cannot open a new tab because that is user preference and he gets to do that, such as CTRL + Click. JavaScript gets to open a new tab only, unless a browser-specific feature allows such,
var win = window.open('www.google.com', '_blank');
win.focus();
Code from: http://stackoverflow.com/a/11384018/1762944, but browser can still control this.
Aniruddha.A wrote: .Dynamically close all browser tab items ,still open remaining single tab item.
As mentioned earlier, you do not get to chose this, unless you control the browser-specific API such as Chrome API for tabs — chrome.tabs - Google Chrome and you would then have an extension in the browser that does all of this — and is still not possible through a web application. If you want to create an extension for this, you can refer that documentation I provided and learn how to manage the tabs from your extension. Extensions can have buttons that you can use.
The sh*t I complain about
It's like there ain't a cloud in the sky and it's raining out - Eminem
~! Firewall !~
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Hi
I have been successfully using Lev's assembly for extracting EXIF data from my jpeg photos. I am particularly interested in the GPS data. Unfortunately I get an error when trying to use the code on Adobe DNG files. Can anyone tell me if a more recent source file is available which supports DNG files?
Best
Grahame
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As you are asking about an article from a member who doesn't look to be active here any more, I would suggest that you look for an alternative to this library. You might find something that suits you here[^].
This space for rent
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Thanks Pete. I had a brief look and though it doesn't explicity mention DNG files, I will further investigate. Thank you!
Grahame
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With the author being active, you stand a much better chance of there being enhancements.
This space for rent
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Using VS2015.
I'm trying to write some code that gives a list a solutions, and when clicked, opens that solution in the CURRENT instance of VS.
So far I have this:
public static class AutomateVS
{
[DllImport("ole32.dll")]
private static extern int CreateBindCtx(uint reserved, out IBindCtx ppbc);
public static DTE GetDTE(int processId)
{
string progId = "!VisualStudio.DTE.14.0:" + processId.ToString();
object runningObject = null;
IBindCtx bindCtx = null;
IRunningObjectTable rot = null;
IEnumMoniker enumMonikers = null;
try
{
Marshal.ThrowExceptionForHR(CreateBindCtx(reserved: 0, ppbc: out bindCtx));
bindCtx.GetRunningObjectTable(out rot);
rot.EnumRunning(out enumMonikers);
IMoniker[] moniker = new IMoniker[1];
IntPtr numberFetched = IntPtr.Zero;
while (enumMonikers.Next(1, moniker, numberFetched) == 0)
{
IMoniker runningObjectMoniker = moniker[0];
string name = null;
try
{
if (runningObjectMoniker != null)
{
runningObjectMoniker.GetDisplayName(bindCtx, null, out name);
}
}
catch (UnauthorizedAccessException)
{
}
if (!string.IsNullOrEmpty(name) && name.Contains("!VisualStudio.DTE.14.0:"))
{
rot.GetObject(runningObjectMoniker, out runningObject);
break;
}
if (!string.IsNullOrEmpty(name) && string.Equals(name, progId, StringComparison.Ordinal))
{
Marshal.ThrowExceptionForHR(rot.GetObject(runningObjectMoniker, out runningObject));
break;
}
}
}
finally
{
if (enumMonikers != null)
{
Marshal.ReleaseComObject(enumMonikers);
}
if (rot != null)
{
Marshal.ReleaseComObject(rot);
}
if (bindCtx != null)
{
Marshal.ReleaseComObject(bindCtx);
}
}
return (DTE)runningObject;
}
}
}
and use it like this
var process = System.Diagnostics.Process.GetCurrentProcess();
var id = process.Id;
_envDTE = AutomateVS.GetDTE(id);
if (_envDTE != null)
{
_envDTE.Solution.Open(solutionFile);
}
But it opens in the wrong VS instance. I need it to open in the instance my app is running in.
Anyone know what's wrong?
Thanks
If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.
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Kevin Marois wrote: But it opens in the wrong VS instance. I need it to open in the instance my app is running in.
In the wrong instance or in a new instance? Because that is what happens, if you even double click a new file to be opened in Visual Studio.
To open a file in a specific version you would require to have a Visual Studio extension, that communicates with Visual Studio to know where to load the file and then it will load the file there.
If you are interested in Visual Studio extensions, go to this link and get to know how you can develop a simple extension that does this for you.
The sh*t I complain about
It's like there ain't a cloud in the sky and it's raining out - Eminem
~! Firewall !~
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I created program where when user checks checkbox edit text is enabled, but when I check any of checkboxes nothing happens!!!
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editText2 = (EditText) findViewById(R.id.editText_symbols);
editText3 = (EditText) findViewById(R.id.editText_numbers);
editText4 = (EditText) findViewById(R.id.editText_lowercase);
editText5 = (EditText) findViewById(R.id.editText_uppercase);
editText2.setEnabled(false);
editText3.setEnabled(false);
editText4.setEnabled(false);
editText5.setEnabled(false);
}
public void checkCheckBox(View view)
{
boolean checked = (((CheckBox)view).isChecked());
switch (view.getId())
{
case R.id.checkBox_uppercase:
if(checked)
editText2.setEnabled(true);
else
editText2.setEnabled(false);
break;
case R.id.checkBox_lowercase:
if(checked)
editText3.setEnabled(true);
else
editText3.setEnabled(false);
break;
case R.id.checkBox_numbers:
if(checked)
editText4.setEnabled(true);
else
editText4.setEnabled(false);
break;
case R.id.checkBox_symbols:
if(checked)
editText5.setEnabled(true);
else
editText5.setEnabled(false);
break;
}
}
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Pavlex4 wrote: nothing happens
Maybe because this is not C#?
Speed of sound - 1100 ft/sec
Speed of light - 186,000 mi/sec
Speed of stupid - instantaneous.
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Instead of flooding these forums with every issue you face, why not try to do some actual debugging of your code first? Also, the above code is not C#, it is Android Java.
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How to do this in Java Android Development?
var _pass = new string(
Enumerable.Repeat(_chars, _len)
.Select(s => s[_rnd.Next(s.Length)])
.ToArray());
modified 8-Jan-17 10:38am.
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First, learn Java.
Second, learn C#.
Then translate the one to the other.
We are not here to do your work for you. And since you are clearly trying to get by without thinking for yourself - your other questions are clear evidence of that - I for one am not prepared to do any more for you. Pull your finger out, learn your subject(s) and start thinking.
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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The best way to translate this is for you to sit down and work out what this code is currently doing. Once you know what this is doing, it becomes a lot easier to translate it into a different language.
This space for rent
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It was always a weird way to do it, certainly took me a minute more time to read than it should. This is particularly offensive since it has a side-effect in code that pretends to be all "pure" and "elegant" and "look at me I'm using enumerables I'm so hip".
What it really does is make a string from _len random characters from _chars, so just implement that however makes the most sense. Which in Java is probably this:
char[] temp = new char[_len];
for (int i = 0; i < temp.length; i++)
temp[i] = _chars[_rnd.nextInt(_chars.length)];
String _pass = String.valueOf(temp);
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1.- When I use the Visual Studio debugger, if the form is large I can not see the code below. How to hide the form?
2.- I have read that I can stop the execution in the debugger (F9) and that I can press Interrupt, Modify a line and Continue. But he will not let me interrupt. How is made? Because now I have to stop the execution and start again.
Thanks
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If you have two monitors, which you should, then drag the form into one monitor and observe the debugging in the other monitor(the one with the VS IDE running). This works for most forms and website debugging.
I have never needed to interrupt a debugging session....ever. Not to say that someone out there doesn't need to do this. I just isolate the code that needs to be debugged, and set breakpoints there, or start from the beginning of the code path, if I need to broaden my scope.
What I do is set a breakpoint close to where the action that I want to observe is going to take place and then run the application. use F10 to advance line by line, and F11 to step into methods. If you need to observe a collection or object variable then just right click on the variable and select Quick Watch...
Go to Youtube and search for .net VS debugging tips and how to videos, if you think that would help you learn more about this.
Edit: You can also use "Run to cursor" if you want to skip sections of code and not have to debug the code line by line. Just place your cursor somewhere further in the code path, and then right click and select run to cursor. I use this a lot to jump over loops or to skip larger areas of code that I don't need to see.
You can also drag the yellow arrow on the left side of the code viewer to a desired code path that has already executed, and repeat "most" code execution again, if needed. This is not good for all scenarios because variables and values can change during the first pass of the code execution. I use this sometimes when debugging Unit Tests, and I want to run the test again without stepping out of the debugger instance.
Also, look into conditional expressions when debugging as well - where applicable.
modified 8-Jan-17 3:36am.
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