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Hello All,
I have an app which has a treeview, and I would like to perform a unique action when the user double clicks a leaf node of the tree. I handled the double click event, but this doesn't tell me much. How do I get to the actual tree node (if any) that the user double clicked on?
Thanks
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Thanks.
But, the problem that I am having is that the dobule click handler is called anytime the user double clicks anywahere in the tree, whether or not the user actually double clicked on a tree node. If I click off in the empty space of the control, the handler is called. The selected node property has a node in it, but I don't have any way to know if that node was actually double clicked.
Aaron
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Try handling the AfterSelect event instead. You can do something like the following:
private void treeView1_AfterSelect(object sender, System.Windows.Forms.TreeViewEventArgs e)
{
TreeNode node = e.Node as TreeNode;
if(node != null)
{
MessageBox.Show(node.Text);
}
}
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Yes, but this will be called if I single click the tree node, won't it? Basically, I need to perform two different actions if the user double clicks a tree node, and if they simply select it (by moving the keyboard, or clicking on it with the mouse). If the double click event args had some more info in them, like mouse coordinates, it would help me figure out if the user actually double clicked a node, or off in space.
My only other thought is to also handle mouse down events, save the corrdinates from these, and use them in the handler to doube click to figure out where the double click happened. This seems pretty messy, surely, there's a cleaner way to do this?
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The GetNodeAt[^] member will tell you the node at a specific point location.
But looking at the docs for DoubleClick[^] event, the TreeView is not supposed to raise a Click or DoubleClick event if the click is not over a node (see below the table before the example.)
-- LuisR
Luis Alonso Ramos
Intelectix - Chihuahua, Mexico
Not much here: My CP Blog!
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Well, the documentation says that it will not, but if I set a breakpoint in the handler for the double click event, and double click somewhere off in the margin of the control (not over a node), the handler is called. The double click event does not contain any mouse location info to use with GetNodeAt. I suppose maybe I could also have a handler for MouseDown, or MouseUp, and save these coordinates for use in the handler for double click, but that seems kind of ugly.
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Hi all..
this is my first post here..
I'm working on a dictionary for the pocket pc platform.. using .NET CF..
the dictionary is 140,000 words..
ofcourse using Ado.net would run my 128mb ram pocke pc "out of memory"(whether it's xml or readline() with a text file)..
so i tried writing the words to an ordinary text file..
it was like 7mb. i thought that using readline() and ArrayList or String array would do just fine... but this was also not efficient...
it will take about 70seconds to load on 400mhz,128 ram..
my question is.. is there any faster way??
i don't want to use c++ as i'm trying to do all my programs in .Net..
Regards,
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You should check this out:
Its a good site, and if I remember it correctly, that would potentially help you sort out your words. I recognize that that wont help your memory problem though, so I would propose something like this:
Keep them in the external file (I suppose you dont really have a choice seeing as you cant load them into memory). Then, on the first time you load the dictionary (also when you make changse but I will let you figure that out) you can document the spot in the file that they are.
How do you find a word? Keep a subset in memory with this algorithm. When you obtain the closest match, go to wherever you need to, and from there search throught the file.
This is just a guess as to how you could do it thought, Im sure there are much better ways,
Luck,
Jim
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Uhhh... What site?
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Wow, it goes to show how baaaaad I am at HTML!
The site was this: http://ciips.ee.uwa.edu.au/~morris/Year2/PLDS210/opt_bin.html
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first a disclaimer: I have zero experience with PDA apps (Im used to Server Apps where I can almost rely on there be more memory than I could use  )
Just wanted to throw an idea out to you, maybe its something you could investigate. It strikes me that what you need is some form of index - so that you can start by making some sort of educated guess as to where the word is.. then you can load a subset of the entire dictionary into memory and search through that for the correct word.
So lets assume you have all the words/meanings in a text file, separated by a newline.
aardvark - An animal
antelope - Another animal
bird - A flying animal
branch - Where birds make their nests
bukakke - er, not suitable
cat - A feline animal
When you install your application, or update your dictioanry data, you could also update/install smaller textfile with an index of where each starting letter begins and ends.. for the above this would be
a, 0, 1
b, 2, 4
c, 5, 5
etc
Now, when you start your app load up the index for future use. When somebody enters a word to lookup, grab the first letter of the word, and query your "index" for the starting and ending location for that letter. Now load up the dictionary data but only store in memory the lines between start->end. Now enumerate this smaller list until you find the right word.
Not sure if this helps but thought it may give you some extra things to think about
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This was the site I was talking about (for ref in my response to this).
http://ciips.ee.uwa.edu.au/~morris/Year2/PLDS210/opt_bin.html
What J4amieC is proposing is in essence similar to what I am saying. Sadly, if you are doing a lot of things really quickly with this dictionary (eg, you were writing a word document!) this would be far too slow! At least, if your memory were really small. Having a read call every time would be pretty taxing. By having this 'weighted tree' you could likely keep a local copy in RAM (as it could be quite small). Thats not to say you couldnt keep a copy of J4amieCs approach in there too. The nice thing is that his is a lot easier Also, you dont need to calculate the weights the first time through.
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Message Closed
-- modified 22-Dec-14 16:55pm.
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Sorry, can you explain what that restriction was a little better? I dont understand you.
As for speed in accessing the indexed files, dont forget that you can cache them too  So if you have a listing that you access all of the time then you might consider building up a cache of those words. Hell, you could even have two caches... a bus... a microprocessor...
^^
Jim
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i can get pixel information using bitmap.getpixel(..) function.
How can i add a semi-trasnsparen color (blue transparent 50%) over another color, that is:
Color myFirstColor = Color.Red;
myFirstColor += Color.FromARGB(50, 0, 0, 255);
That is how can i get a new color got putting over the original color (RED) the new one Blue transparent at 50%?
Thanks
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Christian Graus made a beautiful series of articles on just this topic. Search the articles for "Image Processing" and ye shall find that which ye seeks.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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I'm watching but i've founded nothing about ever if i use pointers.
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I don't understand what your post was supposed to mean. Perhaps in English next time?
The techniques are covered in the code. You'll have to adapt them to your environment.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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i have two projects in my c# solution and i want to pass an event from a form in the 1st project (a dll) to a class in the 2nd project (the program).
but the declaration
public delegate void SomeEventHandler();
in the receiving class is obviously not visible to the sending one, so i cant declare a
public event SomeEventHandler Some;
does anyone have an idea how to do this?
thanks a lot,
frank
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Regex(@"[_A-Za-z]+[A-Za-z]\w*") Can it be improved ?
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improved to do....?
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I want to make it smaller and faster.
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Once again, what does this expression DO?
Smaller and faster is directly influenced by the quality of the data that this expression is supposed to parse. If the incoming data is tight and follows formatting rules properly, then you can probably relax the expression a bit. But if the data is messy, your expression is going to have to be written to deal with that mess.
So, unless you get more specific about what this expression is supposed to do and with what quality of data, there's nothing we can do to help you.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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It finds all the words which start with _ or letter and contains only _ letters numbers.
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