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Ravi thanks for your post, as mentioned in my post, I am not familier with custom controls programming. Need some guidance/tutorial/sample, anything get me started...
Thanks
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See this[^] link. I believe there's a sample you can download.
The actual task is quite simple: you create a User Control (Add New Item | User Control) which is essentially a canvas on which you can drag any number of controls (a la a Form ).
/ravi
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Hi Ravi-ji,
That example shows creating a UserControl; please see my last post on this thread which quotes the MS DataGridView Program Manager (several years ago) on using UserControls in the DataGridView. I'd appreciate your opinion on whether the ... to my mind ... limitations described there would rule out the kind of usage that Ahmed may want.
Also appreciate your opinion on my hypothetical proposal to try and use a sub-classed TextBox (a Component) in a DataGridView TextBox Column.
thanks, Bill
“The best hope is that one of these days the Ground will get disgusted enough just to walk away ~ leaving people with nothing more to stand ON than what they have so bloody well stood FOR up to now.” Kenneth Patchen, Poet
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Yeah, I also posted a link to the PM's post
BillWoodruff wrote: hypothetical proposal to try and use a sub-classed TextBox (a Component) in a DataGridView TextBox Column. I think it might be better to subclass a DataGridViewTextBoxColumn [^]. What do you think?
/ravi
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Ravi thanks for link with sample....I will try it...and let u guys posted....
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And here[^] is a full solution at MSDN.
/ravi
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A question I think you will need to answer here is whether or not a UserControl can be used in the DataGridView in a way that is satisfactory to you. Some years ago the DataGridView Program Manager at Microsoft wrote this:
"There is no recommended way to do this. The DataGridView only supports hosting a user control as an editing control when a cell is in edit mode. Regarding shared rows/cells. When a row becomes unshared the grid raises the RowUnshared event. To unshare a row, the grid calls the row's clone method which in turn clones all its cells.
For a databound grid, the cells to not get their values set since the cells do not store any data -- the underlying datasource stores the data. In the SetValue and GetValue code for a cell it checks to see if the cell/column/grid is databound and if so just retrieves or sets the value to the datasource. This is why you do not get a SetValue call with values as the grid is being displayed. The cell's GetValue method will be called as the grid is being displayed, so maybe you can use that?" Another possibility ... which I am not sure will work ... is the idea of sub-classing a TextBox but putting a Label, or Button, inside it which you can wire-up to get the Click Event.
Yes, you can create such a composite Component; I have done so, and used it successfully. But, the question is: will the DataGridView allow you to put such a sub-classed TextBox in one of its TextBox Columns ?
If someone here with more experience with the DataGridView can answer the question if such a sub-classed Component can be used, I'll be happy to post an example.
“The best hope is that one of these days the Ground will get disgusted enough just to walk away ~ leaving people with nothing more to stand ON than what they have so bloody well stood FOR up to now.” Kenneth Patchen, Poet
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Ravi thanks again for all links....and thanks BillWoodRuff I will appreciate if u can post the sample....
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I have no idea if this is usable in a DataGridView in place of the TextBox normally used in a TextBox Column, but it was fun to write. Once you get a feeling for how easy it is to make new Controls (UserControls), or sub-class existing Controls (make Components), you can develop hybrids for special purposes very easily. The "craft" in it is getting the alignments and re-sizing right.
using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
namespace March17_StateTracking
{
public partial class TBEllipse : TextBox
{
private readonly Label tLabel;
public Label TheLabel { set; get; }
public TBEllipse()
{
InitializeComponent();
tLabel = new Label();
TheLabel = tLabel;
tLabel.Text = "…";
tLabel.FlatStyle = FlatStyle.Flat;
tLabel.BorderStyle = BorderStyle.None;
tLabel.BackColor = Color.Gainsboro;
tLabel.TextAlign = ContentAlignment.TopRight;
tLabel.Margin = new Padding(0, 0, 0, 0);
tLabel.AutoSize = true;
Controls.Add(tLabel);
tLabel.Left = Width - tLabel.Width;
tLabel.Show();
tLabel.Anchor = AnchorStyles.Right | AnchorStyles.Top | AnchorStyles.Bottom;
tLabel.MouseClick += tLabel_MouseClick;
tLabel.MouseHover += tLabel_MouseHover;
}
public TBEllipse(IContainer container)
{
container.Add(this);
InitializeComponent();
}
private void tLabel_MouseClick(object sender, MouseEventArgs e)
{
tLabel.BackColor = Color.Gainsboro;
}
private void tLabel_MouseHover(object sender, EventArgs e)
{
tLabel.BackColor = Color.Lime;
}
}
} After creating an instance of this ... you can test it by drag-dropping it from the ToolBox to a Form after it is compiled ... you can subscribe to the Click Event of the Label. Here's an example of creating an instance in code and adding it to a Form's ControlCollection when a Button on the Form is clicked:
private void TestTBEllipse_Click(object sender, EventArgs e)
{
TBEllipse testTBEllipse = new TBEllipse();
testTBEllipse.Text = "some text";
this.Controls.Add(testTBEllipse);
testTBEllipse.Location = new Point(400,400);
testTBEllipse.TheLabel.Click += TheLabel_Click;
}
private void TheLabel_Click(object sender, EventArgs e)
{
MessageBox.Show("ellipsis label clicked");
}
“The best hope is that one of these days the Ground will get disgusted enough just to walk away ~ leaving people with nothing more to stand ON than what they have so bloody well stood FOR up to now.” Kenneth Patchen, Poet
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Why not just add a column of buttons next to the text column. The simplest and easiest way to do this would be to add an unbound DataGridViewButtonColumn to the DataGridView in the DataBindingComplete event and then handle the CellContentClick event to respond to button clicks.
Sample event handlers for a DataGridView 'dgv' on a Form 'Form1'
int buttonColumnIndex;
public Form1() {
InitializeComponent();
dgv.CellContentClick += new DataGridViewCellEventHandler(dgv_CellContentClick);
dgv.DataBindingComplete += new DataGridViewBindingCompleteEventHandler(dgv_DataBindingComplete);
}
private void dgv_DataBindingComplete(object sender, DataGridViewBindingCompleteEventArgs e) {
DataGridViewButtonColumn bc = new DataGridViewButtonColumn();
bc.Name = "ButtonColumn";
bc.HeaderText = "";
bc.UseColumnTextForButtonValue = true;
bc.Text = "Edit";
bc.AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells;
buttonColumnIndex = dgv.Columns.Add(bc);
dgv.Columns[buttonColumnIndex].DisplayIndex = 0;
}
private void dgv_CellContentClick(object sender, DataGridViewCellEventArgs e) {
if (e.ColumnIndex == buttonColumnIndex) {
MessageBox.Show(String.Format("Edit button clicked on row {0}", e.RowIndex));
}
}
Alan...
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Thanks Alan, I am at present using button column. Actually this textbox with button idea is the inspiration from some popular Accounting softwares. They use in variety of there data entry forms, like for e.g Invoice, when user enter line item, there is column ProductID, when user enters ProductID column he/she can directly enter Product ID or use the ellipse button to show a lookup form. This looks cool, so I thought may be there are some ways we can do it in C# winforms, and by the look of all posts here I am now sure there are more then one ways.
Thanks to all for helping me..I am trying to learn to create custom control, and if there is no success I will stick to button column approach.
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The area of a normal polygon can be calculated using the shoelace formula however one of its limitations is that it must not be complex. I am trying to calculate this given an array of co-ordinates. For the example points:
2,2
1,1
0,2
1,3
1,0
I have been able to construct a script which returns any valid interception points, in the above case this was:
1,1
It then reprints the points in order (including the interception points) in an array with an additional column which is equal to one if the point was added due to it being a valid interception point. This turned out to be:
2,2,0
1,1,0
0,2,0
1,3,0
1,1,1
1,0,0
Now the interception co-ordinate is added in the correct spot to the array of co-ordinates. The task which I am having problems with is being able to calculate the area of a self intercepting polygon. I understand that a complex polygon may be broken up into several simple polygons but do not know how you could write code to do this, or if knowing the interception point the area can be calculated without splitting it up. Any help would be appreciated, Cheers.
I have tried using the logic that four lines will point away from the interception and if you know two of them are connected by another line then that area must be one of the enclosed areas but for more complex polygons (which have multiple intercepts) this does not always work.
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Hello Guys,
I am Developing an Application in Visual Studio 2012 to get some heat transfer parameters as output with some temperature/area inputs. The equations that I want to code in for getting a "heat Transfer Coefficient" are non-linear in nature with cube roots and fourth roots. Such equations can be solved in a single line of code in Mathematica or Matlab but Visual Studio I dont know how can I solve them and return the value. Any help will be appreciated. A sample of such equations in one variable is listed below:
[2*[T+298]^3 + 1.2 * (T-298)^1/3]* [T-298]= [338-T]/0.2
I have to solve for T.
Thank you in Advance.
Nadish
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I'd try an interative approximation: start with some value for T, calculate the formula, change T a little, calculate again, compare the results, and decide for another approximation of T, till you think your result is sufficiently "exact".
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Is it the Fully Qualified Type Name?
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I think the basic idea for the syntax of a "generic" parameter in .NET is that it can be any group-of-glyphs (set of characters) that meaningfully serve as a "place-holder" that will hold, at run-time, any valid .NET Type.
A convention that has developed, and which is used in many books about C# .NET ... though I am not sure it has ever been formalized in the C# language specification ... is to use single characters like "T," and "U," etc., for generic parameter names.
In terms of the syntax of the .NET Types you pass to some Method that receives generic parameters, I think whether or not you must use a fully qualified Type Name depends on the name-scope context in effect at the moment you wish to pass the Type.
So, if you have valid "using" statements in effect, then you can just pass the current valid variable name by itself; if the context does not already provide the ability to use the current name alone, then you must use the fully qualified Type name. Hopefully, you would get a compile-time error if you did not include all the required access syntax for any variable.
Am I understanding what you are asking here correctly ?
“The best hope is that one of these days the Ground will get disgusted enough just to walk away ~ leaving people with nothing more to stand ON than what they have so bloody well stood FOR up to now.” Kenneth Patchen, Poet
modified 17-Mar-14 2:13am.
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BillWoodruff wrote: Am I understanding what you are asking here correctly ?
Nope, but that's because I didn't explain to well.
Let me elaborate.
If I have a Generic class Generic<T> and two normal classes ClassA and ClassB that can be used as Generic<ClassA> and Generic<ClassB> .
How does the Generic<T> class (or actually the compiler) tell the two classes apart? What does the compiler use to identify a class?
The reason that I was asking is that I was trying to use generics with dynamically created classes.
Which of course doesn't work, because the compiler doesn't know about those classes at compile time.
So today the question is merely of academic value to me. But atleast I've learned how to create a class at runtime.
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The clue is in the IL. Consider this assembly:
namespace JorgenQuestion
{
class Program
{
static void Main(string[] args)
{
Chooser<ClassA> chooser = new Chooser<ClassA>();
Chooser<ClassB> chooser2 = new Chooser<ClassB>();
}
}
public class ClassA
{
}
public class ClassB
{
}
public class Chooser<T>
{
}
} Now, the IL that's produced out for the Program class is this:
.class private auto ansi beforefieldinit JorgenQuestion.Program
extends [mscorlib]System.Object
{
.method public hidebysig specialname rtspecialname instance void .ctor () cil managed
{
IL_0000: ldarg.0
IL_0001: call instance void [mscorlib]System.Object::.ctor()
IL_0006: ret
}
.method private hidebysig static void Main (
string[] args
) cil managed
{
.entrypoint
.locals init (
[0] class JorgenQuestion.Chooser`1<class JorgenQuestion.ClassA> chooser,
[1] class JorgenQuestion.Chooser`1<class JorgenQuestion.ClassB> chooser2
)
IL_0000: nop
IL_0001: newobj instance void class JorgenQuestion.Chooser`1<class JorgenQuestion.ClassA>::.ctor()
IL_0006: stloc.0
IL_0007: newobj instance void class JorgenQuestion.Chooser`1<class JorgenQuestion.ClassB>::.ctor()
IL_000c: stloc.1
IL_000d: ret
}
} As you can see, the newobj statements are instantiating the correct classes.
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That's fascinating, Pete: thanks !
I am trying to imagine a real-world scenario in which using the type of generic Classes in this example would be useful, but drawing a blank. Any ideas ?
“The best hope is that one of these days the Ground will get disgusted enough just to walk away ~ leaving people with nothing more to stand ON than what they have so bloody well stood FOR up to now.” Kenneth Patchen, Poet
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I can't come up with anything either.
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Thanks for confirming.
I wish I could give you an extra upvote for doing it by example.
My knowledge map sadly says "Here be monsters" where it should say IL.
So that's added on my todo list.
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