Re: Preventing filedestruction after saving richtextbox contents at program end - C# Discussion Boards

Re: Preventing filedestruction after saving richtextbox contents at program end

24-Jan-09 23:31

Hi all,

the last operation of my program is to store the contents of a richtextbox to a file.
Often the contents of the file will be destroyed.
Saving by hand (button) never destroys the contents.
So it seems that the saving task (asynchronious ???) will be finished too soon at the end of my program.
I inserted a sleeptime to prevent the destruction an to give the savetask the time it needs but that's no solution steadily.

How can I detect, the end of the savetask of the richtextbox before finishing the program ?

tnx
Frank

Wendelius25-Jan-09 0:05

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 0:05

Since the saving can be performed in numerous ways, it's impossible to pinpoint the problem without seeing the code. One reason could be that you don't close the stream, but as said, please post the code.

The need to optimize rises from a bad design.My articles[^]

fracalifa25-Jan-09 0:26

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 0:26

I am simply using the safefile method of the richtextbox control, that's all.

rtxt.SaveFile(Application.StartupPath + "\\log.rtf");

and rtxt is from type System.Windows.Forms.RichTextBox

I did'nt found a method for the RTB like .flush or .close to finish the stream securely.

tnx

DaveyM6925-Jan-09 0:32

DaveyM69

25-Jan-09 0:32

Try this in your FormClosing event handler:

using (System.IO.Stream stream = new System.IO.FileStream(
    Application.StartupPath + @"\log.rtf", System.IO.FileMode.Create))
{
    rtxt.SaveFile(stream, RichTextBoxStreamType.RichText);
}

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

Re: Preventing filedestruction after saving richtextbox contents at program end

fracalifa25-Jan-09 0:59

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 0:59

Thank you,

that sounds good, I will try this.

tnx Frank

Wendelius25-Jan-09 0:35

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 0:35

That should work fine but at which point are you calling this? Is the contents of rtxt possibly destroyed?

The need to optimize rises from a bad design.My articles[^]

fracalifa25-Jan-09 0:56

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 0:56

I call the method as last instruction in the method main[].

tnx frank

Wendelius25-Jan-09 1:02

Re: Preventing filedestruction after saving richtextbox contents at program end

25-Jan-09 1:02

At that point you won't have anything to save. Use FormClosed event instead and save the contents of the control in that event.

The need to optimize rises from a bad design.My articles[^]

DaveyM6925-Jan-09 0:07

DaveyM69

25-Jan-09 0:07

Works fine for me. Where are you calling the SaveFile method from (which event - FormClosing?). Which overload of SaveFile are you using?

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

Data binding

half-life24-Jan-09 22:42

24-Jan-09 22:42

Hi,

i've bounded a TextBox, DateTimePicker and NumericUpDown to a database Via a BindingSource
the thing is that when i change one of the values nothing happens

here is the ButtonClickEvent that should Update the DB

private void button1_Click(object sender, EventArgs e)
{
    t_AppTableAdapter.Update(dataSet2.T_App.Rows[0]);
    dataSet2.AcceptChanges();
}

where do i go wrong??

Have Fun
Never forget it

Wendelius25-Jan-09 0:03

25-Jan-09 0:03

First, set a breakpoint to

t_AppTableAdapter.Update(dataSet2.T_App.Rows[0]);

and check the RowStates and that they are Modified.

If the RowState isn't set, the problem is most likely in binding.

Also the Update method takes a datatable or a datarow array as a parameter. Now you pass only one row. If you want to update all the modifications in the datatable, call:

t_AppTableAdapter.Update(dataSet2.T_App);

The need to optimize rises from a bad design.My articles[^]

half-life25-Jan-09 0:40

25-Jan-09 0:40

Thanks ,

the DataRowState remains "unchanged"
do u know what could be the problem in the bindingsource???

Smile | :)

Have Fun
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Wendelius25-Jan-09 0:51

25-Jan-09 0:51

First you could check that just after modifying a value in a control, the datatable contains the change (and the rowstate is Modified). If the modification is not reflected correctly to the datatable, your control binding isn't correctly.

If the modification is visible in the datatable, then I would suspect that you call either AcceptChanges or RejectChanges somewhere before you call the DataAdapter.Update.

Also it could be possible that you have binded a datatable to the controls, but you are actually trying to save a different datatable (a copy?).

The need to optimize rises from a bad design.My articles[^]

half-life25-Jan-09 1:20

25-Jan-09 1:20

Thanks

but the thing is that the modification is visible,

i can see the dataset.table.rows[0].itemarray[0...].values changing before and after i call the update method and the acceptchanges method Frown | :(

i do not call updatechanges(), certainly not rejectchanges() Before the update method

what do u mean by a copy?? of the datatable,
i've created it once and been using it all along (via the wizard... Add DataBase...)

i think i'm missing somthing maybe in the basics of the concept
Frown | :(

but yet again thanks alot for the help Smile | :)

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Wendelius25-Jan-09 1:34

25-Jan-09 1:34

Ok.

I'm a bit confused since in your earlier post you said that the rowstate was not modified before calling update? So are these correct observations:
- you change the data using a control
- immediately after that, your datatable contains a record with RowState = Modified
- when you come to the point where you call adapter's Update, your datatable doesn't have a record which is Modified?

Also remember that if your datatable contains more than one record, you originally updated only the row at index 0 (t_AppTableAdapter.Update(dataSet2.T_App.Rows[0]);) maybe the record you modified using UI isn't that record. For that reason you should always call t_AppTableAdapter.Update(dataSet2.T_App);

When I wrote about the copy, I meant that is it possible that you actually have two different datatables. Changes are made to one datatable but update is called using another. But if you're sure that you have only one datatable, then this won't be an issue.

The need to optimize rises from a bad design.My articles[^]

half-life25-Jan-09 1:51

25-Jan-09 1:51

Here is the symptom step by step

1. i change the value of a textbox bound to column in table (this table has only 1 Row)
2. before i call the adapter's update method i can see that value has been cahnged in the dataset.
3. after i finish the update the rowstate still stays unchanged, only after i call the acceptchanges the rowstate changes but yet no affect on the *.mdb tables

the dataset is updated but not the data base itself

Frown | :(

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Wendelius25-Jan-09 1:57

25-Jan-09 1:57

The dataadapter calls AcceptChanges when modifications are done so you don't have to call it. Based on those observations, I would guess that the dataadapter isn't trying to update the record.

Two questions:
- have you set adapter's UpdateCommand and if so, what's it like or
- do you rely on the mechanism that UpdateCommand is automatically generated

The need to optimize rises from a bad design.My articles[^]

half-life25-Jan-09 2:11

25-Jan-09 2:11

i rely on the mechanism that UpdateCommand is automatically generated, Why?

iv'e tried to change it and also checked the query before, using the Execute Query Button and it worked fine
until the update method was called in code and this exception came along :
"ERROR [HY104] [Microsoft][ODBC Microsoft Access Driver]Invalid precision value"

so i kind'a backed away from the change

Smile | :)

and again thanks for the help Smile | :)

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Wendelius25-Jan-09 2:23

25-Jan-09 2:23

half-life wrote:
i rely on the mechanism that UpdateCommand is automatically generated, Why?

In order for this to work, you must have a key column in the datatable and the select command must be created using SqlCommandBuilder or OleDbCommandBuilder. Otherwise it won't work.

So you could check that the dataset contains key definition for your datatable.

half-life wrote:
ERROR [HY104] [Microsoft][ODBC Microsoft Access Driver]Invalid precision value

If this is generated by a update command you explicitely supplied, there's propably some mismatch in the columns versus parameter values.

The need to optimize rises from a bad design.My articles[^]

half-life25-Jan-09 2:54

25-Jan-09 2:54

THANKS

i'll try it

and again thank alot for the help and patience Smile | :)

Have Fun
Never forget it

Wendelius25-Jan-09 2:59