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Lambda's look cool Cool | :cool:

It's either searching through the collection and keeping the result around, or hardcoding them in advance. Attributes that mark a set of fields as a group might be another option, but that would add a bit more complexity.

No, I think I like the lambda better. Would also be cool combined with a regex Smile | :)

Nearly forgot, but that cast in my original query would be redundant, as we'd only need to store labels;

C#

class Form1
{
    IEnumerable<Label> summingLabels; 
    public Form1()
    {
    	InitializeComponent();
	
    	summingLabels =
    		from c in Controls.Cast<Control>().AsQueryable()
    		where c.GetType() == typeof(Label)
    		&& c.Name.StartsWith("label")
    		select c as Label;
    
    	// later on, when you need them
    	foreach(Label l in summingLabels)
    		l.Text = l.Location.ToString();
    }
}

I are Troll Suspicious | :suss:

Or Maybe to make it nicer with no casting and type checking:

C#

summingLabels =
    		from c in Controls.OfType<Label>()
    		where c.Name.StartsWith("label")
    		select c;
    
    	// later on, when you need them
    	foreach(Label l in summingLabels)
    		l.Text = l.Location.ToString();

Yup, works, and more concise and readable Thumbs Up | :thumbsup:

I are Troll Suspicious | :suss:

The correct answer is: don't do that

If you need multiple storage locations (variables) and access them by index, use an array.

If you really have multiple variables (e.g. because they are generated by the VS forms designer), then you can still put those into an array:

Label[] labels = { labela1, labela2, labela3 };

Hear hear!

David Knechtges wrote:
Is there a way to do that?

No, at least if I understand what you want... However, why would you want to do that? What's wrong with:

Label[] labela = { 
 labela0,
 labela1,
 labela2,
 labela3,
};
//...
for (int i=0;i<4;i++)
 labela[i].Text = "something";

modified on Wednesday, September 1, 2010 5:55 PM

This answer was already posted hours ago.

[Forum Guidelines]

You can also try reflection if you really really really really really really really really must do it this way and not using array/collection (depending on a situation).

Don't forget to rate answer, that helped you. It will allow other people find their answers faster.

Try to use this construction:

this.GetType().GetField("variablename")

This should work for c# but better try to avoid such kind of code. Other languages has different RTTI, for example in c/c++ this is impossible at all.

Not sure about the performance implications of FindControl.. But this one is pretty close to what you originally wrote

for (int i=1;i<4;i++)
   (Controls.FindControl("labela" + i.ToString()) as Label).Text = "something";

This is not exactly what you were asking for but is an alternative using binding. This may be overkill for what you are trying to do but it would be more elegant. Bind your labels as you create them to an object of a class that implements INotifyChanged then when you change the property of the object each label will be updated without having to work loops.

http://stackoverflow.com/questions/639894[^]

Dave

Array.ForEach(new Control[] { labela1, labela2, labela3 }, delegate(Control c) { c.Text = "something"; });

How to do this is quite simple, but not obvious since we do not normally think of dimensioning a variable as a control type.

The simplest way (to me) is to dimension an array of labels, Label(1), Label(2) etc. as Label. Then set each member of the array equal to each of the labels you want to control a property for.

Then you can write a loop setting a property of each label in the array as an iterated function, such as:

Dim Label(1) as Label
Dim Label(2) as Label ...

Label(1) = LabelA
Label(2) = LabelB ...

For x = 1 to 5
Label(x).text = "Text " & x
Next

(Sorry, I am an old VB.NET programmer, but the concept is the same in all Big Grin | :-D

)

I think this is what you want, works great for me, and works for the other common controls, too.

take a look at the dictionary class

There has to be tools in Visual Studio 2008 for outlook that we can add to my software to allow us to connect via outlook connection to exchange.... so , which one can do that?

drag and drop a lable whit c#.net

At it's most basic:

Capture the mouse down event. Use the mouse offset while moving the label round. Capture the mouse up event.

I have CDO, it's OCD with the letters in the right order; just as they ruddy well should be

Forgive your enemies - it messes with their heads

My blog | My articles | MoXAML PowerToys | Onyx

Yours is not a question at all.

"I love deadlines. I like the whooshing sound they make as they fly by." (DNA)

Smithers-Jones wrote:
Yours is not a question at all.

Sure it is. It says question in the title. Roll eyes | :rolleyes:

I have CDO, it's OCD with the letters in the right order; just as they ruddy well should be

Forgive your enemies - it messes with their heads

My blog | My articles | MoXAML PowerToys | Onyx

If a question at all, it's a questionable question. Smile | :)

[Forum Guidelines]

Start here[^] if you're using WPF, or here[^] if you're building WinForms. There's code-examples for multiple .NET languages, and you can select the .NET version that you need by clicking the link at the top of the page.

--edit;
As an additional remark, not as criticism, but to help you get a better answer sooner; it would have helped if you had put the phrase "Drag and Drop" in the "subject"-line of your post. A few hints on your current environment (VB.NET, C++, .NET 1.1, .NET 4) are usually helpful too.

I are Troll Suspicious | :suss:

You didn't post a question at all.

But, if you want to know how to do it, read my article on the subject, here[^].

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

(i posted this incorrectly to quick answers. I am reposting this here)

I am working on my first C# SQL project. A simple checkbook register.

I referred to the CodeProject article:

Using the DataGrid Control Using the DataGrid Control[^]

I added a datagridview control to my form and set the data source as my checkbook register in SQL Express.

I am able to see all the checkbook entries when I run the form.

My first attempt at updating the sql table is generating a compile error.

The error is:
cannot convert from 'System.Data.DataSet' to 'FirstCheckBookInSQL.CheckBookManagementDataSet.CheckbookUSBPersonalDataTable'

I've been researching this for 3 days, but I'm just not making sense of what I am seeing.

Can someone help please!
Thank you.
Mark

My code in Form1.cs:

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.Data.SqlClient;

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

        }

        
        private void Form1_Load(object sender, EventArgs e)
        {
            // TODO: This line of code loads data into the 'checkBookManagementDataSet.CheckbookUSBPersonal' table. You can move, or remove it, as needed.
            this.checkbookUSBPersonalTableAdapter.Fill(this.checkBookManagementDataSet.CheckbookUSBPersonal);
        }

        private void TBDbutton_Click(object sender, EventArgs e)
        {

            DataSet myChangedDataSet = this.checkBookManagementDataSet.GetChanges();
            if (myChangedDataSet != null)
            {
                // get how many rows changed

// this is the line I am having trouble with:
                int modifiedRows = this.checkbookUSBPersonalTableAdapter.Update(myChangedDataSet);

                //MessageBox.Show("Database has been updated successfully: " +
                //modifiedRows + " Modified row(s) ", "Success");
                this.checkBookManagementDataSet.AcceptChanges();
                myChangedDataSet.AcceptChanges();

            }

            MessageBox.Show("no data changed");
        }
    }
}
</pre>

You didn't "incorrectly" post this to Q&A, I think the answer from CG was suggesting that you might want to use the Message facility at the end of the article you referenced, rather than raise a new general question thread. However, since the article is about the use of a standard .NET component a general question is perfectly valid. Don't worry about CG - Quantas probably sucks again! And don't worry about that, CG is well known for sucky things...

The first thing I would say is: since you are doing a winforms project, I would avoid using DataGrid and use DataGridView instead - it's a little more advanced, and a bit easier to play with.

However, the error you are gettign is a bit specific:

cannot convert from 'System.Data.DataSet' to 'FirstCheckBookInSQL.CheckBookManagementDataSet . CheckbookUSBPersonalDataTable'

with your code

int modifiedRows = this.checkbookUSBPersonalTableAdapter.Update(myChangedDataSet);

What it means is "Update expects a DataTable, you are providing a CheckbookUSBPersonalDataTable. Please give me a DataTable instead".
When you defined CheckbookUSBPersonalDataTable, did you derive it from DataTable? Or does it contain a DataTable and you forgot to refer to it? Because if not, then you cannot supply it to the Update method.

Real men don't use instructions. They are only the manufacturers opinion on how to put the thing together.

I actually meant to say I added a DataGridView control to the form. My bad.

The only code I personally wrote was what I copied into my post. Any other code for creating DataTables, DataSet, DataAdapters, etc. was generated by VS2008.

What's weird is that intellisence is looking for a DataSet parameter being passed to the Update function.

I would think a DataTable would be more restrictive since that's only a single table, whereas the DataSet would include a collection of my tables correct?

I putzed around trying a datatable argument in the Update function, but since I didn't know what I was doing, I didn't have much success.

Mark Smile | :)