Problem in editing xml file through Dom parser.

[wysota]

If a file is 10 bytes long and you seek to the beginning and write 8 bytes, the file will remain to be 10 bytes long -- you will only modify the first 8 bytes, leaving the last two unchanged. If you want to discard the remaining bytes, you need to truncate the file.

[Niamita]

but i did not seek the file at the time of editing. Have you look at the xml file which generate after editing it.
Please give me some sample code.
Thanks.

[wysota]

I have already said everything I had to say, you have all info you need, just make proper use of it -- this is not kindergarden. Analyze your own code and reach your own conclusions. I can only repeat -- if you want to have the file be shorter than it was before, you need to truncate the file. This is general programming knowledge, nothing related to Qt or even C++.

[ChrisW67]

but i did not seek the file at the time of editing.

Sure you did...

root1.appendChild(statement);
file->seek(0);
static int i =1;
table->setRowCount(i);

root1.appendChild(statement);
file->seek(0);
static int i =1;
table->setRowCount(i);

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The whole approach needs revision IMHO. Assuming the XML file is fairly small, the process is:

• Read the whole document in the DOM from disc or create an "empty" DOM document if no file exists yet
• Create/modify the document in the DOM using the relevant methods and whatever UI
• Write the whole DOM document back to disc overwriting the old file if one exists.

No fiddling about with read/write files or trying to update in-situ. You should be able to draw solid dividing lines between the three elements.

[wysota]

...and truncate the file if you intend to write less than the previous content of the file.