C# Window App : Setting Datasource Dynamically

[pod]

Hello


I have a form which contains several textboxes and comboboxes

I am able to loop through all the controls on this form and set the value (ctl.Text) to the Textboxes

but if I try to set the datasource (ctl.DataSource), I get an error during the build.

(when I type a DOT after ctl, I can see the Text property but not the Datasource one)

Here are my two functions, load_Labels works fine but I can't even build the app when I uncomment the datasource line in the load_DropDowns function

I also tried casting but it doesn't like it either.

If you can find the error in my code, I would really appreciate your feedback

Thanks,

Perry

        void load_Labels()
        {
            try
            {
                int rw = -1;
                string sSQL = @"SELECT * FROM tbl_Label WHERE ynLabel_archive = false   AND intLabel_phase = 1 ORDER BY intLabel_id ASC; "
 
                newDS = classObj.GetDataSet(sSQL);
 
                foreach (Control ctl in this.tabPage1.Controls)
                {
                    if (ctl.Name.IndexOf("_textbox") > 0)
                    {
                        //this sets the Question ID
                        rw = Convert.ToInt32(getQuePos(ctl.Name)) - 1;
                        ctl.Text = newDS.Tables[0].Rows[rw].ItemArray[2].ToString();
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("load_Labels:" + ex.Message);
            }
        }
 
        void load_DropDowns()
        {
            try
            {
                int rw = -1;
                string sSQL = @"SELECT intStatus_id FROM tbl_Status;";
 
                newDS = classObj.GetDataSet(sSQL);
 
                foreach (Control ctl in this.tabPage1.Controls)
                {
                    if (ctl.Name.IndexOf("_combobox") > 0)
                    {
                        ctl.DataSource = newDS.Tables[0];
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("load_DropDowns():" + ex.Message);
            }
        }
 

[Plater]

Those controls don't support the DataSource property.

[mikeyeli]

i say you try a different way of doing the same thing..

Plater is right.
there is no DataSource property for "Control".
so thats the problem.. you must cast it to ComboBox first.
just do it like my example code below:

try:

foreach(object o in this.tabControl1.TabPages[0].Controls)
            {
                if(o is System.Windows.Forms.ComboBox)
                {
                    ((System.Windows.Forms.ComboBox)o).DataSource = getSource().Tables[0];
                }
            }

[pod]

that's exactly what I needed to know, I have not tried it yet but it showed me more on how to program with Objects

Thanks

Perry

i say you try a different way of doing the same thing..

Plater is right.
there is no DataSource property for "Control".
so thats the problem.. you must cast it to ComboBox first.
just do it like my example code below:

try:

foreach(object o in this.tabControl1.TabPages[0].Controls)
            {
                if(o is System.Windows.Forms.ComboBox)
                {
                    ((System.Windows.Forms.ComboBox)o).DataSource = getSource().Tables[0];
                }
            }

[pod]

this works well, I can capture every object (or should I say instance) and set the datasource to it. But I need to capture the name of the instance as well and I can't if I use

foreach(object o in this.tabControl1.TabPages[0].Controls)

could someone tell me how I can capture the name of the instance and still be able to set the datasource ?

Thanks

i say you try a different way of doing the same thing..

Plater is right.
there is no DataSource property for "Control".
so thats the problem.. you must cast it to ComboBox first.
just do it like my example code below:

try:

foreach(object o in this.tabControl1.TabPages[0].Controls)
            {
                if(o is System.Windows.Forms.ComboBox)
                {
                    ((System.Windows.Forms.ComboBox)o).DataSource = getSource().Tables[0];
                }
            }

[Plater]

Use this isntead:

foreach(Control c in this.tabControl1.TabPages[0].Controls)
 

Then you can get at like the .ID or .Name tag to see what they are called.

[mikeyeli]

this works well, I can capture every object (or should I say instance) and set the datasource to it. But I need to capture the name of the instance as well and I can't if I use

foreach(object o in this.tabControl1.TabPages[0].Controls)

could someone tell me how I can capture the name of the instance and still be able to set the datasource ?

Thanks

remember object has no Name property, but ComboBox does, so as simple as before.

C#:

((System.Windows.Forms.ComboBox)o).Name

foreach(object o in this.tabControl1.TabPages[0].Controls)
{
    if(o is System.Windows.Forms.ComboBox)
    {
        string myNameIs = ((System.Windows.Forms.ComboBox)o).Name
        ((System.Windows.Forms.ComboBox)o).DataSource = getSource().Tables[0];
    }
}

if you need to use that combo for several things besides setting the datasource, it would be a real pain typing ((System.Windows.Forms.ComboBox)o) every time, so what you can do is set a variable the onjects reference

C#:

System.Windows.Forms.ComboBox currentCombo = ((System.Windows.Forms.ComboBox)o);

cool huh!?

so now the code would look like :

foreach(object o in this.tabControl1.TabPages[0].Controls)
{
    if(o is System.Windows.Forms.ComboBox)
    {
        System.Windows.Forms.ComboBox currentCombo = ((System.Windows.Forms.ComboBox)o);
        string myNameIs = currentCombo.Name;
        currentCombo.DataSource = getSource().Tables[0];
    }
}

and you can use currentCombo, for anything you want from there on(well before the if "end bracket").

[pod]

Mikeyeli, Yo da Man!

I tried casting it but was using the wrong property, control instead of combobox

Thanks,

Perry :-D



[quote=mikeyeli]remember object has no Name property, but ComboBox does, so as simple as before.

C#:

((System.Windows.Forms.ComboBox)o).Name

.......

[Plater]

Mikeyeli, Yo da Man!

I tried casting it but was using the wrong property, control instead of combobox

You were casting it as an Object, not as a Control, casting as a Control would have given you access to .Name and such.

[pod]

I meant to say that from within the OBJECT foreach LOOP ...

foreach (object obj in this.tabCtl.TabPages[0].Controls)
...I was able to get to the DATASOURCE property.

((System.Windows.Forms.ComboBox)obj).DataSource

But instead of keeping the same casting[i]...to get the NAME property, I used

((System.Windows.Forms.Control)obj).Name ..... within the same foreach loop

I am slowly getting used to the Object way of thinking, I keep stumbling at every step, but with your help, I am getting it.

Thank you both for your help, it is greatly appreciated

Perry :-D

You were casting it as an Object, not as a Control, casting as a Control would have given you access to .Name and such.