xamarin - Can I use C# code to add a call to a command instead of a <Grid.GestureRecognizers>? -

i have code:

<viewcell x:name="co">    <grid verticaloptions="centerandexpand" padding="20, 0">       <grid.gesturerecognizers>          <tapgesturerecognizer command="{binding openpickercommand}" commandparameter="{x:reference copicker}" numberoftapsrequired="1" />       </grid.gesturerecognizers>       <picker x:name="copicker" isvisible="false" horizontaloptions="end" selectedindexchanged="copickerselectedindexchanged" itemssource="{binding order}"></picker>       <label x:name="colabel" horizontaloptions="end"/>    </grid> </viewcell> 

is there way can in c# connect command tapping of cell rather have use xaml <grid.gesturerecognizers> ?

adding gesturerecognizer viewcell big no-no. viewcell exists within listview or tableview have more enough tapped options of own. adding gesturerecognizer might confuse os tap should handle.

your options gesturerecognizer following 3, advise against them in scenario have listview/tableview.

check out of listview/viewcell based alternatives mention below in situation.

---

1. gesturerecognizer - add in code

var tapgesturerecognizer = new tapgesturerecognizer(); tapgesturerecognizer.tapped += (s, e) => {     // handle tap }; mygrid.gesturerecognizers.add(tapgesturerecognizer); 

2. gesturerecognizer - use command

when use mvvm can use command binding in c#:

var tapgesturerecognizer = new tapgesturerecognizer(); tapgesturerecognizer.setbinding (tapgesturerecognizer.commandproperty, "tapcommand"); mygrid.gesturerecognizers.add(tapgesturerecognizer); 

which can bound in xaml:

<grid>     <grid.gesturerecognizers>         <tapgesturerecognizer command="{binding tapcommand}" />     </grid.gesturerecognizers> </grid> 

3. gesturerecognizer - add in xaml have done

<grid>       <grid.gesturerecognizers>          <tapgesturerecognizer command="{binding openpickercommand}" commandparameter="{x:reference copicker}" numberoftapsrequired="1" />       </grid.gesturerecognizers> </grid> 

---

4. viewcell - tapped event

for viewcell have tapped event:

<viewcell height="100" tapped="ontapped">     <viewcell.view>         <stacklayout backgroundcolor="white" >         </stacklayout>     </viewcell.view> </viewcell> 

which can implement in code-behind:

void ontapped (object sender, system.eventargs e) { //your code} 

5. viewcell - tapped command

when using mvvm don't want put lot of business logic in code-behind pages. in case can use behavior convert event command. sample of can found here:

https://github.com/xamarin/xamarin-forms-samples/tree/master/behaviors/eventtocommandbehavior/eventtocommandbehavior

---

6. listview - itemselected

listview has itemselected event. can handled same way viewcell tapped event both event in code-behind or behavior delegate command.

7. listview - selecteditem property

you can bind selecteditem property in view model. on setter can perform custom code.

<listview     itemssource="{binding youritems}"     selecteditem="{binding yourselecteditem, mode=twoway}" > </listview> 

and in code:

string _yourselecteditem; public string yourselecteditem {     { return _yourselecteditem; }     set {         _yourselecteditem = value;         // perform custom functionality     } }