c# - Save an Image/Bitmap from hidden panels -

i have tabcontrol 4 tabs, , every tab contains panel. want save panels 1 click, can save panel in front.

do know way ?

bitmap eins = new bitmap(p1.width, p1.height); eins.save(".string."+1+".jpg",system.drawing.imaging.imageformat.jpeg); 

i don't see filling bitmap.

this should work panels, no matter tabpage on:

foreach (panel px in new panel[] { p1, p2, p3, p4 } )     using (bitmap bmp = new bitmap(px.clientsize.width, px.clientsize.height))     {         px.drawtobitmap(bmp, px.clientrectangle);         bmp.save(somefolder + px.name + ".jpg", system.drawing.imaging.imageformat.jpeg);     } 

in fact work if panels actually invisible , not in 1 of hidden tabpages !

of course must make sure panels have unique , filename compliant names..

update: know have controls inside panel , not graphics draw , maybe backgroundimage, can understand problems had..

unfortunately tabpages have nasty way of hiding embedded controls.

so wrote little helper routine doesn't cause more blink of main form going inactive , back..:

void savehiddencontrol(control ctl, string filename) {     control originalparent = ctl.parent;      form fff = new form();     fff.opacity = 0;     ctl.parent = fff;     fff.show();     system.drawing.imaging.imageformat fmt = system.drawing.imaging.imageformat.jpeg;     if (filename.tolower().endswith(".png")) fmt = system.drawing.imaging.imageformat.png;     using (bitmap bmp = new bitmap(ctl.clientsize.width, ctl.clientsize.height))     {         ctl.drawtobitmap(bmp, ctl.clientrectangle);         bmp.save(filename, fmt);     }     ctl.parent = originalparent;     fff.close(); } 

here result:

note how form transparent , yet lets panel drawtobitmap fine, including image, ellipse , 2 controls , independent of form.size ..!

update2 , here function dosn't blink @ all, @ least if panel indeed not visible:

void savehiddencontrol(control ctl, string filename) {     control originalparent = ctl.parent;     int oldleft = ctl.left;     ctl.left = 22222;  // way outside     ctl.parent = this;     system.drawing.imaging.imageformat fmt = system.drawing.imaging.imageformat.jpeg;     if (filename.tolower().endswith(".png")) fmt = system.drawing.imaging.imageformat.png;     using (bitmap bmp = new bitmap(ctl.clientsize.width, ctl.clientsize.height))     {         ctl.drawtobitmap(bmp, ctl.clientrectangle);         bmp.save(filename, fmt);     }     ctl.parent = originalparent;     ctl.left = oldleft; } 

this moves panel onto main form way right, won't show. saves , moves back. of course should check if panel indeed on hidden tabpage or else blink; in case original routine do..