Hi ,
For reference type, you can judge this by the "is" keyword.
For value type, I think you should create a signable table for
suitable conversion, such as
int-value&float-type,int-value&double-type
float-value&double-type,int-value&long-type
and so on,
In you function, you can determine the logic through this table.
Hope this helps,
Best regards,
Jeffrey Tan
Microsoft Online Partner Support
Get Secure! -
www.microsoft.com/security
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--------------------
| From: (e-mail address removed) (CA)
| Newsgroups: microsoft.public.dotnet.languages.csharp
| Subject: Re: Can an object be cast into a certain type?
| Date: 23 Sep 2003 21:40:47 -0700
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|
| Basically what I am trying to do is to develop a generic function at
| the base level class that verifies whether or not the data entries to
| the user interface are valid.
|
| So the base class would have the form:
|
| public abstract class BaseDataEntry
| {
| public bool HasValidType(Type t, Value o);
| public abstract object Value { get; set; }
| }
|
| At the level of the derived class, one would just set the type and
| hopefully the base class function would determine whether or not it is
| valid. I suppose I could override the function at the derived class
| level.
|
| I guess what I am try to prevent is to add an additional else if each
| time I add a new class. The reason why comparing the types directly
| does not work for me is that
|
| float valF = 1.0F;
| bool ret = HasValidType(typeof(double), valF); // should return true
|
| Thanks for taking the time to reply to my post.
|
| Regards
|
| Chris
|
| --------------------------------------------------------
|
| The reason I am reluctant to compare the types directly as suggested
| earlier
| > Use the 'as' syntax for testing if a cast succeeded. If you are like
me, you
| > are trying to minimize the number of try, catch statements.
| >
| > object [] myObjects = new object[6];
| > myObjects[0] = new MyClass1();
| > myObjects[1] = new MyClass2();
| > myObjects[2] = "hello";
| > myObjects[3] = 123;
| > myObjects[4] = 123.4;
| > myObjects[5] = null;
| >
| > for (int i=0; i<myObjects.Length; ++i)
| > {
| > string s = myObjects
as string;
| > Console.Write ("{0}:", i);
| > if (s != null)
| > Console.WriteLine ( "'" + s + "'" );
| > else
| > Console.WriteLine ( "not a string" );
| > }
| >
| > HTH,
| > Eric Cadwell
| > http://www.origincontrols.com
| >
| >
| > | > > Hi,
| > >
| > > I have a function where I would like to test whether an object is of a
| > > certain type. Here is my code so far.
| > >
| > > public bool HasValidType(Type t, object val)
| > > {
| > > try
| > > {
| > > if (t==typeof(double))
| > > {
| > > double x = (double) val;
| > > }
| > > else if (t==typeof(System.DateTime))
| > > {
| > > DateTime x = (DateTime) val;
| > > }
| > return true;
| > > }
| > > catch
| > > {
| > > return false;
| > > }
| > > }
| > >
| > > I guess what I would like is the ability to write a statement of the
| > > form
| > >
| > > try
| > > {
| > > t variable = (t) val;
| > > return true;
| > > }
| > > catch
| > > {
| > > return false;
| > > }
| > >
| > > Can I do this using reflection? I appreciate any help in this matter.
| > > Thanks in advance.
| > >
| > > Chris
|