how to Call a function with string variable?

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is it possible to call a function at runtime with the string variable??

I created a form in which one textBox and a Button. In my code i Created a function name is CallMe(). I want when the textBox text is "CallMe()" and then the button clicked, that function automatically Call...

Thanks in Advance.....

Posted 14-Jan-13 3:25am

JayantaChatterjee

Updated 14-Jan-13 3:27am

v2

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Comments

Sandeep Mewara 14-Jan-13 9:28am

Not clear. Please re-phrase/elaborate.

David_Wimbley 14-Jan-13 9:28am

Your question is not very clear, what platform is this? Asp.net? Winforms? WPF?

It should be a matter of attaching a click event to the button, whether its Winforms/WPF/Asp.net but it would be nice to know for sure what platform.

JayantaChatterjee 14-Jan-13 9:34am

the platform is winforms..

JayantaChatterjee 14-Jan-13 9:38am

I mean, if at runtime i type "CallMe()" in textBox and then Clicked the button, the function automatically which name match that variable value.....
Please Help me..............

4 solutions

Solution 1

I think you mean that if the user types the name of a function in the textbox and presses a button, that the text he typed should be treated as code and executed, yes?

If so, then it is possible, but I would very strongly recommend against it. What if what they type is

File.Delete(@"%USERPROFILE%\*.*");

Would it be a good idea to execute that? And there are much, much worse things they could do...

Please, think again about what you want to do - there are some programs you shouldn't let your mates get anywhere near...

Posted 14-Jan-13 3:40am

OriginalGriff

Comments

JayantaChatterjee 14-Jan-13 9:43am

I appreciate your suggestion...
but i want to call function which i defined in my code...

Solution 2

This is how to dynamically call a method at runtime.

C#

Type type = Type.GetType(type);
object obj = Activator.CreateInstance(type);
MethodInfo method = type.GetMethod("YourMethodNameGoesHere");
method.Invoke(obj, null);

I just hammered that out real quick, not sure if it works but should point you in right direction

To call with parameters

C#

object[] paramsArray = new object[] { "Im A String Param" };
methodInfo.Invoke(method, paramsArray);

Posted 14-Jan-13 3:45am

David_Wimbley

Updated 14-Jan-13 4:02am

v3

Comments

JayantaChatterjee 14-Jan-13 9:53am

I'm getting error ->

Type type=Type.GetType(type);//The best overloaded method match for 'System.Type.GetType(string)' has some invalid arguments

can u tell me which directive I use for MethodInfo???

David_Wimbley 14-Jan-13 10:00am

Unless you post your code i have no idea what your type is, its Namespace.Classname.

JayantaChatterjee 14-Jan-13 10:03am

My Code is ->

private void okBtn_Click(object sender, EventArgs e)
{
Type type = Type.GetType(type);
object obj = Activator.CreateInstance(type);
MethodInfo method = type.GetMethod(textBox1.Text);
method.Invoke(obj, null);
}
private void CallMe()
{
MessageBox.Show("In Call Me..");
}

David_Wimbley 14-Jan-13 10:03am

Can you post your namespace/classname?

JayantaChatterjee 14-Jan-13 10:06am

using System;
My namespaces -:
using System.Windows.Forms;
using System.Reflection;

Error is -: Type type=Type.GetType(type);//The best overloaded method match for 'System.Type.GetType(string)' has some invalid arguments

David_Wimbley 14-Jan-13 10:08am

No i mean the namespace of your App.

Example

namespace DavidWimbley.Application.App
{
public class DavidsClass
{
public void DavidsMethod
{

}
}
}

Then your line would need to be "DavidWimbley.Application.App.DavidsClass" for your type

JayantaChatterjee 14-Jan-13 10:08am

My Class Name is -: Form1

JayantaChatterjee 14-Jan-13 10:11am

sorry ...

my Namespace is -: ForPrintPre

David_Wimbley 14-Jan-13 10:16am

So your line should be Type type=Type.GetType("ForPrintPre.Form1");

JayantaChatterjee 14-Jan-13 10:24am

Now the error move to here -:

method.Invoke(obj, null);//Object reference not set to an instance of an object.

JayantaChatterjee 14-Jan-13 11:04am

object obj = this.GetType().InvokeMember(textBox1.Text, BindingFlags.InvokeMethod | BindingFlags.Public | BindingFlags.Static, null, null, null);

I found this code ,but at the runtime i getting error that "Method 'ForPrintPre.Form1.CallMe()' not found."

My Namespace is -:ForPrintPre.
Class Name is -: Form1.

Please Help Me ......

David_Wimbley 14-Jan-13 11:05am

You need to make sure your CallMe method is public, not private...right now according to what you posted above your CallMe method is private.

JayantaChatterjee 14-Jan-13 11:12am

I change the access specifier from private to public ..
still I'm getting same error .... :-(

JayantaChatterjee 14-Jan-13 11:17am

My code is -:

using System;
using System.Windows.Forms;
using System.Reflection;

namespace ForPrintPre
{
public partial class dynamicMethodCall : Form
{
public dynamicMethodCall()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
object obj = this.GetType().InvokeMember(textBox1.Text, BindingFlags.InvokeMethod | BindingFlags.Public | BindingFlags.Static, null, null, null);
}
public void CallMe()
{
MessageBox.Show("In Call Me Method.");
}
}
}

David_Wimbley 14-Jan-13 11:18am

Ok ill take a look give me a bit

Solution 4

Hello
i Got Your Query You Want Whent You enter Text In textbox means Function Name And Click Button it will Invoke Your Function.

So'

For this You Can Click button curser transfer your btn Event
then you check What you type in your textbox and invoke your function like:-

CallMe()

and
perform your function.
but also know your function call back your button click event .

Posted 18-Jan-13 22:07pm

rizwan muhammed khan gouri

Comments

JayantaChatterjee 22-Jan-13 7:24am

I want its totaly depend on users input(Dynamically) invoked function...

rizwan muhammed khan gouri 22-Jan-13 7:44am

Use principle of thread

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David_Wimbley · Accepted Answer · 2013-01-14T05:28:00

I ran this and it will call the ShowMessage method on click from the button1 event

C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Reflection;

namespace WindowsFormsApplication4
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }


        public static void ShowMessage()
        {
            MessageBox.Show("Called Me Dynamically!");
        }

        private void button1_Click(object sender, EventArgs e)
        {
            object obj2 = typeof(Form1).GetMethod("ShowMessage").Invoke(null, null);
        }
    }
}

how to Call a function with string variable?

4 solutions

Solution 3

Solution 1

Solution 2

Solution 4

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