C# Reflection, Creating Instance from string

Question

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I have many Forms...and also I have a string that contain name of Form that must be Show...
for Example...I have TObjectForm and ApplianceForm
and string str = "ApplianceForm"
I need to create this form using this string that contain name of form that must be opened...
I use this...

C#

Type type = Type.GetType(typeName);
Form item = (Form)Activator.CreateInstance(type);

but it is error ArgumentNullException...but my string -> typeName is for example "ApplianceForm"...but it is error...

Posted 16-Feb-12 9:50am

SilenthillpH

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2 solutions

Solution 1

You can use this:

C#

object oform;
oform = System.Reflection.Assembly.GetExecutingAssembly().CreateInstance("
[namespace].[formname]");
((Form)oform).Show();

replace the namespace with your application/form namespace and [formname] with the name of your form.

Posted 16-Feb-12 10:20am

aidin Tajadod

Comments

SilenthillpH 16-Feb-12 16:27pm

still a NullReference Exception...oform is null...I don't know why ?
I use this..
Type type = Type.GetType(typeName, true);
Form item = (Form)Activator.CreateInstance(type);
item.ShowDialog();

and it is still error...it can't load this type
//Additional information: Could not load type 'TObjectForm' from assembly 'HouseDataBase, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.

aidin Tajadod 16-Feb-12 16:38pm

what about the code if posted. do you still getting error? are you entring the right NameSpace?

SilenthillpH 16-Feb-12 16:51pm

no...stil error..
http://clip2net.com/s/1Bn1b
http://clip2net.com/s/1Bn1D
http://clip2net.com/s/1Bn1U
http://clip2net.com/s/1Bn2f
http://clip2net.com/s/1Bn2Y
http://clip2net.com/s/1Bn3t
http://clip2net.com/s/1Bn3G
....I don't know why.... ?

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SilenthillpH · Accepted Answer · 2012-02-16T11:34:00

Solution 2

C#

string formTypeFullName = string.Format("{0}.{1}", this.GetType().Namespace, typeName);
Type type = Type.GetType(formTypeFullName, true);
Form item = (Form)Activator.CreateInstance(type);
item.ShowDialog();

type name need full name like this -> HouseDataBase.TObjectForm

Posted 16-Feb-12 11:34am

SilenthillpH

Comments

Abhi261989 19-Nov-14 13:41pm

thanx