Home Forums WPF controls Xceed DataGrid for WPF Scrolling grid content when dragging vertical scrollbar thum

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    #21621 |

    I noticed that dragging the vertical scrollbar’s thumb button doesn’t really scroll the grid content. Scroll operation occurs only after I release mouse button.

    However, some samples (like “Xceed.Grid.Samples.DataBinding.exe”) from the “Bin\.NET\” directory do show such behavior.

    I wonder how would I make the dataGridControl scrollable by (at least vertical) scrollbar thumb dragging?

    Imported from legacy forums. Posted by Alexander (had 5999 views)

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    The Xceed.Grid.Samples.DataBinding is a showcase for the <i>Xceed Grid for .NET</i> product and not the <i>Xceed DataGrid for WPF</i>.

    We decided to make the scrolling only when the Thumb was “dropped” to prevent the performance hit, inherent to WPF, when generating large amount of visual items (in other words, scrolling while dragging the thumb would have caused lags, which we found even more bothering).

    There is a way to restore the “live” scrolling with the DataGrid control (if this is truly important for you); however, it will be at the expense of some grouping functionalities.

    Let me know if you still want to know how to do it.

    Imported from legacy forums. Posted by Marcus [Xceed] (had 1153 views)

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    First it is great to see a commercial release of a WPF control. I posted about it on an Avalon MSDN forum last night. It had 27 views this morning.

    I was curious how you would implement scrolling and expected the scrolling behavior that you currently have due to performance reasons. I think that the best approach between performance and navigational help would be to have a “tool tip” so that when you are scrolling you can see the contents of a single cell hovering over the scroll bar. The tool tip could display the cell from the row that will be the top row when you release the mouse, or perhaps the row that would be in the middle might be better.

    Imported from legacy forums. Posted by Stage (had 556 views)

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    Thank you for your interest as well as for your kind words…

    I think you have a great idea there (cell’s tool tip), it has been noted, and we’ll see what we can do for upcoming releases.

    Keep posting your suggestions and/or comments, we appreciate every one of them.

    Imported from legacy forums. Posted by Marcus [Xceed] (had 428 views)

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    Thanks Marcus,
    How bad would it influence the grouping capabilities? Would the grouping loose the advantage of UI virtualization like existing Microsoft’s WPF ListView control?
    What I want is to give users some visual feedback when dragging the scroll thumb.
    The alternative to content scrolling (and realizing/derealizing a lot of DataRow objects) might be some triggers or animations added to DataRow’s style that would change colors and/or opacity etc. when thumb dragging is detected. Any idea how my Xceed.Wpf.DataGrid.DataGridControl derived class could obtain the “dragging” state of the scroll thumb?

    Imported from legacy forums. Posted by Alexander (had 611 views)

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    Unfortunately yes, the workaround would have you revert to the MS Grouping (which does not have any UI virtualization).

    What I can tell to help you is that when dragging the thumb, the offset properties of the ScrollViewer’s are changing live, at the same time, the ScrollChanged event from the ScrollViewer is triggered live. The offset parameters of IScrollInfo from the ItemsPanel also gets updated live.

    You could somehow hook to the ScrollChanged event and apply some animation/transform onto whatever fits your need.

    Imported from legacy forums. Posted by Marcus [Xceed] (had 684 views)

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    Thanks Marcus,
    I’ll try that

    Imported from legacy forums. Posted by Alexander (had 328 views)

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    Are you planning on fixing this? This is a deal blocker for us.

    We had a flowsheet control that we ourselves implemented and the performance was abysmal. It was easy for us to blame it all on WPF. Then I got ahold of it, spent some time on low hanging fruit, then rewrote most of the core engine, and it now scrolls close to real time.

    Imported from legacy forums. Posted by Ed (had 752 views)

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    Good news, you can obtain the fix here : http://download3.xceedsoft.com/Packages/3.2.7559.11410/XceedComponents.exe

    Imported from legacy forums. Posted by Matt (had 6060 views)

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    all that did was download a bunch of examples onto my computer, and when I used the libraries in the Bin folder I had the same issue with scrolling. can you please explain how this is the fix? Thanks

    Imported from legacy forums. Posted by ImaDragonrider (had 313 views)

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    The most obvious coding change that is required is that ItemScrollingBehavior should be set to Immediate rather than Deferred.

    Imported from legacy forums. Posted by Derek (had 2874 views)

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