PrefetchToFolder bug

[zontick]

I try download tiles with new version mapwingis 4.6.9.1 and remarked what after some minets of downloading function begin save empty files. They have png header, but have empty data.

Then i try 4.6.9.0 and get same result.
Next version 4.5.9 where tiles save without extension. Download tiles, change extension and get empty tiles.
Back on version 4.9.3.4 and get normal tiles.

[pmeems]

I'm a bit confused by the version numbers you're using. I'm assuming their typos.
As I understand it:

• The current latest version v4.9.6.1 is fetching empty tiles.
• v4.9.5 is also fetching empty tiles
• v4.9.3.4 is getting correct files

Is this only happening with OSM data or also with other tile providers?

[pmeems]

Can you also show the code your using so I can debug it?

[pmeems]

I created my own unit test and can't reproduce the empty tiles:

Perhaps it is a flaw on the server, which is sending back a wrong image?
Or is the empty tile perhaps an error response? Can you change the extension to txt and open it in a text editor?

[zontick]

You right about versions, it is was my typos.
This is part of code. I try only google provider.
On level 11 get half empty tiles. From level 12 get all empty tiles.

            int iCountTile=0;
            int ilevel=0;
            Extents ext = new Extents();
             ext.SetBounds(30, 10, 0, 45, 50, 0);
            int iTileProv = (int)tkTileProvider.GoogleMaps;
             string sDir = @"G:\TileTest";
            for (ilevel = 1; ilevel <= 14; ilevel++)
            {
                iCountTile = axMap1.Tiles.PrefetchToFolder(ext, ilevel, iTileProv, sDir, ".png", null);
            }

This is empty tile

[pmeems]

Could you try OSM or Bing?

Since MW5 we no longer support Google Maps because they changed their license.
It is no longer allowed to use their tiles in non-webbased applications.
Most likely that is the cause of your problems.

[zontick]

Bing map do not work.
I try OSM and looks like it work, but speed of downloading is unreal slow.
Then got empty tiles I use machine with OS win7 x64, now I try it on another machine with win10 x64, and get no empty tiles but crashes application. It is happens about the same time of work then must be empty tiles downloads.
Then I try OpenCycleMap end get same crash.
Then i back on version 4.9.3.4 and no empty tiles and crashes.
Can you try this code on you machine with google or OpenCycleMap?

[pmeems]

Using GoogleHybrid I can reproduce the creation of the invalid PNG-files.
I've created https://mapwindow.atlassian.net/browse/MWGIS-126 for this and will investigate this further.