Re: bitmap background issue and resources - C# Discussion Boards

bitmap background issue and resources

3-Feb-05 8:37

If your XML file does not change, then I don't see why this would differ. You should really be using an XPath to find the node you want though, this way is incredibly clunky.

If the document was not fully loaded, it would not be valid XML, and none of this would work.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

Aviv Halperin3-Feb-05 0:48

Aviv Halperin

3-Feb-05 0:48

Hi,
I have 2 questions regarding bitmaps:

1)I have a small bitmap (16/16 pixels) that I'm using in my application.
I need to set its background to transparent.

When I use the code

MyBitmap.MakeTransparent(Color.White);

all the white pixels become blue instead of transparent!!!

Does anyone know whats going on here?

2) Is it possible to save a bitmap as part of the C# project and open it this way instead of installing the bitmap file and opening in the file way:
string bmpPath = @"c:\MyBitmap";
Bitmap MyBitmap= new Bitmap(bmpPath);

Thanks.

avivhal

Judah Gabriel Himango3-Feb-05 5:03

Judah Gabriel Himango

3-Feb-05 5:03

It is highly recommended that white and black not be used as transparent colors. Microsoft recommends using magenta (255, 0, 255) or green (0, 255, 0).

I don't know that transparent white is the cause of your problem, though. Worth a try anyway, that is, until Heath comes along and gives you a better answer than I can.

Tech, life, family, faith: Give me a visit.
Judah Himango

Aviv Halperin3-Feb-05 6:48

Aviv Halperin

3-Feb-05 6:48

Thanks, but I tried gray before and got same result.

avivhal

Christian Graus3-Feb-05 8:41

3-Feb-05 8:41

1. TRy creating an imageattributes class instance and setting the transparent key on that. I didn't know bitmaps had a MakeTransparent method, I've never used it.

2. Yes, absolutely. Just make the bitmap part of your project, then change it's properties so that it is an embedded resource. Then you can load it as a resource, using code like this:

		private static Bitmap GetImageFromResources(string name)<br />
		{<br />
			// get a reference to the current assembly<br />
			Assembly a = Assembly.GetExecutingAssembly();	<br />
<br />
			string my_namespace = a.GetName().Name.ToString();<br />
<br />
			Bitmap image = new Bitmap(a.GetManifestResourceStream(my_namespace + "." + name));<br />
<br />
			return image;<br />
		}

Put that functions somewhere and call it to load your bitmaps. The name can need qualification by namespace, depending on where in the project it is.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

Aviv Halperin3-Feb-05 22:57

Aviv Halperin

3-Feb-05 22:57

Thanks.
I changed the code a bit since it did not work properly.
My code is:

public static Bitmap GetImageFromResources(string name)
{
// get a reference to the current assembly
System.Reflection.Assembly a = Assembly.GetExecutingAssembly();

string my_namespace = a.GetName().Name.ToString();//not needed since return assembly name

string[] ResourceNames = a.GetManifestResourceNames();
string ImageFullName="";

for(int i=0 ; i < ResourceNames.Length ; i++)
if(ResourceNames[i].ToUpper().IndexOf(name.ToUpper()) != -1)
{
ImageFullName = ResourceNames[i]; break;
}

Bitmap image =
new Bitmap(a.GetManifestResourceStream(/*my_namespace + "." +*/ ImageFullName));

return image;
}

Problem was that a.GetName().Name.ToString(); does not return the name space in which the code is running but rather the assembly name.

Thanks again.

avivhal

ODBC Programming

Adnan Siddiqi2-Feb-05 23:45

Adnan Siddiqi

2-Feb-05 23:45

Hello

I need help for the following:

1)Retrieve DSN list in Combo Box
2)After Selecting the DSN,select the Database
3)After Selection of Database,it list down all tables and their associated fields

-Is it possible?kindly guide me

Thanks
-adnan

Re: ODBC Programming

Heath Stewart3-Feb-05 0:17

3-Feb-05 0:17

You can create interop assemblies (RCWs, or Runtime Callable Wrappers) for both the ADODB and MSDASC libraries and use the same functionality other applications use to select and edit data links (DSNs). See my previous post at http://www.codeproject.com/script/comments/forums.asp?msg=841196&forumid=1649&XtraIDs=1649&searchkw=DataLinksClass&sd=11%2F15%2F1999&ed=2%2F3%2F2005#xx841196xx[^] for details.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

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Multi-monitor

SquallBlade2-Feb-05 23:19

SquallBlade

2-Feb-05 23:19

Is it possible to see how many monitors there are connected to your pc and how to draw on them with second display not as extended desktop.

The goal is to see a application in fullscreen on second monitor but if the program stops that the screen turns black.

I have found some GDI examples for C++ but not what i was expecting. I want to enable and disable the second display through code and not by using a application or a windows setting.

Please help me,

Squall Blade

Re: Multi-monitor

Heath Stewart2-Feb-05 23:23

2-Feb-05 23:23

Lookup the Screen class in the .NET Framework SDK. You can get the number of display devices using Screen.AllScreens.Length, and you can draw on a specific screen by using its Screen.Bounds to draw into.

For examples click "Search comments" directly above this message board to search this forum. We've discussed this many times in the past and I remember even posting a sample or two. It's really not hard to figure out, however, if you read the .NET Framework SDK documentation.

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Software Design Engineer
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Microsoft

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Transparent tabcontrol

Member 8094092-Feb-05 22:54

Member 809409

2-Feb-05 22:54

Hello all happy coders! Smile | :)

I have a problem and would be very happy to get some help.
I have a tabcontrol that I want to make transparent. I can make the tabs transparent but not the tabcontrol. There is no propertie on the tabcontrol that I can use to set the background. HELP!

Thanks!

Best regards!
/Erik

Reflection question

Christian Graus2-Feb-05 18:25

2-Feb-05 18:25

We have an n tiered app with a class that represents objects in our system, and a lot of the properties for that class are sub entities that we define, and so on. Our client is writing a web service that sends us XML, which we use to update our objects, and we're using an approach where we create lists of properties and use reflection in a central method, so that if I pass in an object of type A, and a string that is "B.C.D.E", and an object that is, for example, set to be true, the reflection code gets the B property of A, then uses the returned object to get the C property and so on, until it has D. Then it works out the type of the object being passed in, converts the XML string to that type, and finally uses reflection to set D.E = true.

This all works pretty well, but we have a property which is indexed by an enum, and values for setting properties for the resultant object, for each of the enum values. So, my input string is something like B.C[MyEnum.D].E and once I have an object of type B, I need to get the object returned by referencing the property C, passing in the enum value of D. Does that make sense ? I hope so. My problem is that I can't figure out how, if I have an object, of type B, and "C", "MyEnum" and "D" as string arguments, I can use reflection to end up with the final property, so I can proceed to set it's E property.

In other words, if I have an object, how do I use reflection to retrieve a property which is indexed by an enum value ?

Thanks for any help.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

Robert Rohde2-Feb-05 20:15

Robert Rohde

2-Feb-05 20:15

First to the MyEnum.D part:
You will have to get the Type corresponding to your "MyEnum" string. As you seem to be relatively far I think you can do this yourself Smile | :)

. To get the corresponding value for "D" use the Enum.Parse method -> now you have the indexer argument.

An indexer is internally converted to one or more methods. Those are named with get_Item and set_item. You can see that easily when using a decompiler like Reflector on your program.
To get the values you now cna do the same as when invoking any other method:

<br />
myType.InvokeMember("get_Item", BindingFlags.InvokeMethod, null, myObject, new object[] { myIndexerValue })<br />

Christian Graus3-Feb-05 10:09

3-Feb-05 10:09

Thanks, but it doesn't seem to be working for me. Pls read my reply to Heath for an update on where I am at....

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

Heath Stewart2-Feb-05 23:19

2-Feb-05 23:19

Keep in mind, however, that an indexer is not always the Item property. This can be controlled using the System.Runtime.CompilerServices.IndexerNameAttribute, so you should actually enumerate all properties and find the one with the IndexerNameAttribute, falling back to the Item property.

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Microsoft

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Christian Graus3-Feb-05 10:08

3-Feb-05 10:08

Hi Heath. This is what I have so far

PropertyInfo info = target.GetType().GetProperty(match.Groups[1].Value);
ParameterInfo [] infs = info.GetGetMethod().GetParameters();
target = target.GetType().InvokeMember(info.GetGetMethod().Name, BindingFlags.Public | BindingFlags.Instance | BindingFlags.InvokeMethod, null, target, new object[] { DerivativeCategory.Compilation });

where target is the object that holds the indexed property, and match.Groups[1].Value is the property name. The ParameterInfo object I get in the second line tells me that the get functions has no parameters, so now I'm kind of stuck. Yes, for now I am trying to put in a static value, until I have a ParameterInfo I can get the enum type from to use the string I have in my RegEx match collection.

So I passed in something like:

SublicenceRights.SubLicensedRights.DevelopRights.Derivatives[IPRM.DerivativeCategory.SupplementaryWork].CopyrightOwnerInForegroundIP

and when I got to the point where target is of type DevelopRights, I am getting the Derivatives get method, expecting it to take an instance of the DerivativeCategory enum, but it doesn't.....

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

Christian Graus3-Feb-05 11:00

3-Feb-05 11:00

Thanks again - I've worked it all out. I needed to get the property, then look for the get_Item method on that property. I was expecting I could use the get_PropertyName method.

I'm not clear on how the IndexerNameAttribute works, but I'm going to read up on the MethodInfo.Attributes property, and hopefully all will become clear.

Christian

I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer

Heath Stewart3-Feb-05 11:10

3-Feb-05 11:10

The IndexerNameAttribute lets you change the name of the indexer as languages like VB.NET see it (and when you reflect the Type, of course). By default, the following C# yields an indexer named Item:

public class MyClass
{
  public object this[int index]
  {
    get { return index; }
    set { ; }
  }
}

Lets say that for VB.NET the term "Item" doesn't make as much sense as something else, perhaps "Something" (bad example, but I'm tired today). You can use the IndexerNameAttribute to give it that name when it compiles, such that the same code above yields an indexer named Something (and the getter and setter methods would be get_Something and set_Something, respectively).

The String.Chars property is just such an example.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

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Christian Graus3-Feb-05 11:13