Is there a chance to imprive Python for .net to let "System.Windows.Forms.Form().Controls" be indexable?

[1989lzhh]

Hi,

here  is the code:

import clr

clr.AddReference("System.Windows.Forms")

from System.Windows.Forms import Form,Application,Button

form=Form()

form.Controls.Add(Button())

print form.Controls[0] #this code didnt work with an error say "not indexable object"

but this worked in ironpython,it seems in ironpython it treats the "form.Controls" as an list like object 

I can only get the form.Controls value use the "form.Controls.get_Item(0)" in the python for .net

So is there a chance to imprive Python for .net to have that characteristic?

thanks

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[Barton]

Yes, this is well worth looking into. I may be able to get to this this weekend.
Thank you.

On 8/31/2011 10:30 PM, 刘振海 wrote:

Hi,

here  is the code:

import clr

clr.AddReference("System.Windows.Forms")

from System.Windows.Forms import Form,Application,Button

form=Form()

form.Controls.Add(Button())

print form.Controls[0] #this code didnt work with an error say "not indexable object"

but this worked in ironpython,it seems in ironpython it treats the "form.Controls" as an list like object 

I can only get the form.Controls value use the "form.Controls.get_Item(0)" in the python for .net

So is there a chance to imprive Python for .net to have that characteristic?

thanks

_________________________________________________
Python.NET mailing list - [hidden email]
http://mail.python.org/mailman/listinfo/pythondotnet

_________________________________________________
Python.NET mailing list - [hidden email]
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[Barton]

Very interesting;
Apparently, Microsoft doesn't think that it is a useful thing to index directly into a System.Windows.Forms.Control.ControlCollection Class.
The collection is still iterable in versions above 2.0, but the class no longer supports indexing. So:

>>> print form.Controls[0]         # works in pythondotnet built on .NET 2.0 on prior.
<System.Windows.Forms.Button object at 0xaa8bc6c>
>>>

for ctrl in form.Controls:
    print ctrl    # works in .NET 3.0 and above.


Compare
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.controlcollection_properties.aspx
with
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.controlcollection_properties%28VS.80%29.aspx
and you'll see that all ICollection and IList properties have been removed.

Reasons why are a good topic for future discussion.

On 8/31/2011 10:30 PM, 刘振海 wrote:

Hi,

here  is the code:

import clr

clr.AddReference("System.Windows.Forms")

from System.Windows.Forms import Form,Application,Button

form=Form()

form.Controls.Add(Button())

print form.Controls[0] #this code didnt work with an error say "not indexable object"

but this worked in ironpython,it seems in ironpython it treats the "form.Controls" as an list like object 

I can only get the form.Controls value use the "form.Controls.get_Item(0)" in the python for .net

So is there a chance to imprive Python for .net to have that characteristic?

thanks

_________________________________________________
Python.NET mailing list - [hidden email]
http://mail.python.org/mailman/listinfo/pythondotnet

_________________________________________________
Python.NET mailing list - [hidden email]
http://mail.python.org/mailman/listinfo/pythondotnet

[Barton]

Here's a snippet that may help a little if you really need to get at a control that has been added to a parent control:

import clr
import System
clr.AddReference("System.Windows.Forms")
from System.Windows.Forms import Form, Button

myBtnName = "button1"

form1 = Form()

def AddButton(form, btnName):
    btn = Button()
    btn.Name = btnName
    btn.Text = "Click Me"
    form.Controls.Add(btn)

AddButton(form1, myBtnName)

ctrls = form1.Controls.Find(myBtnName, False)
btn = ctrls[0]
if isinstance(btn, Button):
    print repr(btn)
    print btn.Name

System.Windows.Forms.Application.EnableVisualStyles()
System.Windows.Forms.Application.Run(form1)



On 9/2/2011 8:17 PM, Barton wrote:

Very interesting;
Apparently, Microsoft doesn't think that it is a useful thing to index directly into a System.Windows.Forms.Control.ControlCollection Class.
The collection is still iterable in versions above 2.0, but the class no longer supports indexing. So:

>>> print form.Controls[0]         # works in pythondotnet built on .NET 2.0 on prior.
<System.Windows.Forms.Button object at 0xaa8bc6c>
>>>

for ctrl in form.Controls:
    print ctrl    # works in .NET 3.0 and above.


Compare
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.controlcollection_properties.aspx
with
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.controlcollection_properties%28VS.80%29.aspx
and you'll see that all ICollection and IList properties have been removed.

Reasons why are a good topic for future discussion.

On 8/31/2011 10:30 PM, 刘振海 wrote:

Hi,

here  is the code:

import clr

clr.AddReference("System.Windows.Forms")

from System.Windows.Forms import Form,Application,Button

form=Form()

form.Controls.Add(Button())

print form.Controls[0] #this code didnt work with an error say "not indexable object"

but this worked in ironpython,it seems in ironpython it treats the "form.Controls" as an list like object 

I can only get the form.Controls value use the "form.Controls.get_Item(0)" in the python for .net

So is there a chance to imprive Python for .net to have that characteristic?

thanks

_________________________________________________
Python.NET mailing list - [hidden email]
http://mail.python.org/mailman/listinfo/pythondotnet

_________________________________________________
Python.NET mailing list - [hidden email]
http://mail.python.org/mailman/listinfo/pythondotnet

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[1989lzhh]

Hi Barton,

Thanks for your reply,I really appriciate!

Here is my thought:

在 2011年9月4日 上午3:35，Barton <[hidden email]>写道：

Yes, I agree that the Item Property is still there.
It seems to be exposed ONLY FROM IEnumerator.GetEnumerator() or the Findxxx() functions provided by the class due to its virtual nature:

public virtual Control this [ int index ] { get; }

    I don't think the Item Property isn't exposed due to its virtual nature. I did some test in C#,it turns out that the virtual modified Item property can be accessed by python .net with the index manner .I noticed there is a new function "get_Item"  being add to the instance object. The same new function "get_Item" can be find in the Form().Controls but Form().Controls can not be indexable. It is wield.

I check the source code of python for .net and find this from "classmanager.cs":

                   // Check for indexer

                    ParameterInfo[] args = pi.GetIndexParameters();

                    if (args.GetLength(0) > 0) {

                        Indexer idx = ci.indexer;

                        if (idx == null) {

                            ci.indexer = new Indexer();

                            idx = ci.indexer;

                        }

                        idx.AddProperty(pi);

                        continue;

                    }

Maybe the mechanism of checking for indexer is not perfect?

Thanks!

 

Hope that helps

On 9/3/2011 7:09 AM, 刘振海 wrote:

Hi Barton，

thanks for your reply.

I have check the MSDN documents. It seems the Item properties both exist in .net2.0 and .net4.0 

here is the MSDN for http://msdn.microsoft.com/en-us/library/system.windows.forms.control.controlcollection_properties%28VS.80%29.aspx

	Item[Int32]	Indicates the Control at the specified indexed location in the collection.
	Item[String]	Indicates a Control with the specified key in the collection.

and I get the blew code from C# 

"

public class ControlCollection : ArrangedElementCollection, IList, ICollection, IEnumerable, ICloneable  {

public virtual Control this[int index] { get; }

public virtual Control this[string key] { get; }

"

In C# the Controls support index,So I think It will be intuitive for Controls to support index. 

2011/9/3 Barton <[hidden email]>

Very interesting;
Apparently, Microsoft doesn't think that it is a useful thing to index directly into a System.Windows.Forms.Control.ControlCollection Class.
The collection is still iterable in versions above 2.0, but the class no longer supports indexing. So:

>>> print form.Controls[0]         # works in pythondotnet built on .NET 2.0 on prior.
<System.Windows.Forms.Button object at 0xaa8bc6c>
>>>

for ctrl in form.Controls:
    print ctrl    # works in .NET 3.0 and above.


Compare
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.controlcollection_properties.aspx
with
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.controlcollection_properties%28VS.80%29.aspx
and you'll see that all ICollection and IList properties have been removed.

Reasons why are a good topic for future discussion.

On 8/31/2011 10:30 PM, 刘振海 wrote:

Hi,

here  is the code:

import clr

clr.AddReference("System.Windows.Forms")

from System.Windows.Forms import Form,Application,Button

form=Form()

form.Controls.Add(Button())

print form.Controls[0] #this code didnt work with an error say "not indexable object"

but this worked in ironpython,it seems in ironpython it treats the "form.Controls" as an list like object 

I can only get the form.Controls value use the "form.Controls.get_Item(0)" in the python for .net

So is there a chance to imprive Python for .net to have that characteristic?

thanks

_________________________________________________
Python.NET mailing list - [hidden email]

http://mail.python.org/mailman/listinfo/pythondotnet

_________________________________________________
Python.NET mailing list - [hidden email]
http://mail.python.org/mailman/listinfo/pythondotnet

[Barton]

OK - I'll look into this further. It turns out the .NET 3.5 DOES allow this:

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Button btnCopy;
            Button btn = new Button();
            this.Controls.Add(btn);
            btnCopy = (Button)this.Controls[0];
            bool yes = (btn == btnCopy);
        }
    }
}

On 9/3/2011 8:31 PM, 刘振海 wrote:

Hi Barton,

    I don't think the Item Property isn't exposed due to its virtual nature. I did some test in C#,it turns out that the virtual modified Item property can be accessed by python .net with the index manner .I noticed there is a new function "get_Item"  being add to the instance object. The same new function "get_Item" can be find in the Form().Controls but Form().Controls can not be indexable. It is wield.

I check the source code of python for .net and find this from "classmanager.cs":

                   // Check for indexer

                    ParameterInfo[] args = pi.GetIndexParameters();

                    if (args.GetLength(0) > 0) {

                        Indexer idx = ci.indexer;

                        if (idx == null) {

                            ci.indexer = new Indexer();

                            idx = ci.indexer;

                        }

                        idx.AddProperty(pi);

                        continue;

                    }

Maybe the mechanism of checking for indexer is not perfect?

Thanks!

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Python.NET mailing list - [hidden email]
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