Re: C# Windows Application seems to be not responding! - C# Discussion Boards

load combobox from xml [modified]

7-May-07 2:47

Create a BackgroundThread for processing the file. If you are storing the data read from the file in memory, make sure it does not consume too much ( Check the return value of FileStream.Read which returns the number of bytes read and add them to a "long totalBytesRead = 0;" variable each time as "totalBytesRead += bytesRead" and check:

if(totalBytesRead <= (1024*1024*50)) // more than 50 MB
{
ReadMore();
}
else
{
ProcessCurrentData();
CleanMemory(); // reset the read buffer forexample
}

And don't forget Application.DoEvents(); method Wink | ;)

Hope this helps...

Planker5-May-07 3:48

5-May-07 3:48

I am trying to load a list of number in a combobox, it seems to be reading the xml file elements but it is reading my numbers as the index for the combobox

here is my xml file data that is is reading

<Days>21, "21"</Days>
<Days>20, "20"</Days>
<Days>19 19</Days>
<Days>18</Days>
<Days>17</Days>
<Days>16</Days>
<Days>15</Days>
<Days>14</Days>
<Days>13</Days>
<Days>12</Days>
<Days>11</Days>
<Days>10</Days>

all i get is a blank drop down list, if you want to see the code let me know but the code is working to read the other elements and filling text boxes

-- modified at 9:53 Saturday 5th May, 2007

CPallini5-May-07 6:23

CPallini

5-May-07 6:23

Well, as you guessed, posting relevant code will be helpful.
BTW your XML file doesn't seem very elegant, for instance, in:

<br />
<Days>21,"21"</Days><br />

you enclose two pieces of info inside a single item. Maybe it is not a good idea.

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Planker5-May-07 6:45

5-May-07 6:45

xtr = new XmlTextReader(filename);

while (xtr.Read())
{
if (xtr.NodeType == XmlNodeType.Element)
{
if (xtr.LocalName.Equals("Days"))
{
this.cbodays.Items.Add(xtr.Value);
}
}
}
the <Days>21,"21"</Days> was just test data, I was trying to use the <Days>20</Days> but that gave me just the blank drop down box, so i was wondering if it just took my numbers and made them the index of the combobox so I put a few different data formats in the XML file to see if that made any difference

I have used a switch statement to check for XmlNodeType.Element and gives same results, if I change .equals("days") to an name that is not in the file I just get one blank drop down, currently it looks like it see that there are the right number of records but no data in the drop down

Rob

CPallini5-May-07 8:57

CPallini

5-May-07 8:57

Planker wrote:
this.cbodays.Items.Add(xtr.Value);

Substitute xtr.Value with xtr.ReadElementString() in the above line.

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Planker5-May-07 11:39

5-May-07 11:39

Thank you, that worked. is there a reason that xtr.Value works for text boxes and you need readelementstring for combobox?

CPallini5-May-07 11:55

CPallini

5-May-07 11:55

No, there isn't. I think that xtr.Value doesn't work for text boxes too. But I must test it...tomorrow...maybe!

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Planker6-May-07 18:44

6-May-07 18:44

thank you for your help, wondering if you could answer a question about writing back to the xml file.
I think you are right, I looked at my other code again and i was using ReadString

I am getting an error at run time on this line of code

newDayIndex.InnerXml = index.ToString();

here is how i'm doing all the xml code

XmlTextReader reader = new XmlTextReader(C_strFileName);
XmlDocument doc = new XmlDocument();
doc.Load(reader);
reader.Close();
XmlNode oldIndex;
XmlElement root = doc.DocumentElement;
oldIndex = root.SelectSingleNode("/config/Days_Index");
XmlElement newDayIndex = doc.CreateElement("Days_Index");
newDayIndex.InnerXml = index.ToString();
root.ReplaceChild(newDayIndex, oldIndex);
doc.Save(C_strFileName);

AFSEKI7-May-07 2:53

7-May-07 2:53

1) You should first correct these:

<days>21, "21"
<days>20, "20"

2) Then check if it you are really reading the values from the XML file correctly.

3) Use Convert.ChangeType(...) to convert the values you read to a specific type if you want.

4) Update ComboBox.DataSource Property with the list of values you read ( check out MSDN Library for ComboBox.DataSource Property on how to add specific, custom data sources to ComboBox )

Hope this helps...

Planker7-May-07 4:03

7-May-07 4:03

Thanks for the info, i got the loading of the combobox working, i am not trying to figure out how to save the changes back to the xml file if the user changes the value.

AFSEKI7-May-07 22:45

7-May-07 22:45

I know that you are not trying to save back the user modified values to the XML file. What I suggest using Convert is to give you the ability to store the datatype of the object(what ever you create) as a string value and then convert it to what you want. You may also write a custom type converter or implement iSerializable interface or add XmlAttributes to your fields for which you want to serialize.

Planker8-May-07 1:20

8-May-07 1:20

yes I am trying to save back the user modified values. I'm updating a config file so when the program is shutdown the changed value is read the next time the program is run.

AFSEKI8-May-07 21:07