c# - Func and lambda question -

-

i have declaration of

void test (func<bool> f)

i have method bool getitem(string id)

i can call test ( ()=>getitem("123")), why?

i suppose can check need 1 string parameter.

func<bool> expects function returns bool. func<t1> has 1 output argument, func<t1, t2> takes function input t1 , output t2. each successive version allows additional input argument, final generic type being type of output argument.

ex.: func<string, string, bool> able invoke bool dostuff(string s1, string s2)

quick edit clarify: test( () => getitem("123")) works because start of lambda declaration exposes no input arguments, , getitem returns boolean.


Comments

Post a Comment

Popular posts from this blog

android - Spacing between the stars of a rating bar? -

-
ho can set spacing beween stars? thats ratingbar: ratingbar = (ratingbar) inflater.inflate(r.layout.ratingbar, null); ratingbar.setlayoutparams(new layoutparams(layoutparams.wrap_content, layoutparams.wrap_content)); the layout: <?xml version="1.0" encoding="utf-8"?> <ratingbar xmlns:android="http://schemas.android.com/apk/res/android" style="@style/mystyle" android:layout_alignparentright="true" android:layout_height="19dp" android:layout_width="wrap_content" android:numstars="5"> </ratingbar> the style: <style name="mystyle" parent="@android:style/widget.ratingbar"> <item name="android:progressdrawable">@drawable/android_r2_ratingstar_yellow</item> <item name="android:indeterminatedrawable">@drawable/android_r2_ratingstar_grey</item> </style> thanks, cheers you have
Read more

aspxgridview - Devexpress grid - header filter does not work if column is initially hidden -

-
i'm using devexpress grid , i'm trying 'country' column display header filter properly: <dx:gridviewdatacolumn caption="country" fieldname="countryname" showincustomizationform="true" visible="false"> <settings allowheaderfilter="true"/> </dx:gridviewdatacolumn> if 'country' column set visible='true', header filter displayed should(it shows value option list). however, want 'country' column hidden, available in customization window(like in code above). in case, when column dragged outside customization window , grid , header filter clicked, javascript error encountered: element null element.addeventlistener(eventname, func, true); is known bug? there workarounds? set aspxgridview.settings.showheaderfilterbutton property true resolve problem. the following markup works fine me (i using dxperience 10.1.7): <asp:accessdatasource id="accessda
Read more

c# - How to execute a particular part of code asynchronously in a class -

-
i creating speech recognition engine that's going respond user commands.i have created button enable , disable speech recognition per user convenience.i have used dispose() of speech engine disable speech recoginition.here code private void button1_click(object sender, routedeventargs e) { engineon = !engineon; if (engineon) { speechengine = speech.createspeechengine(); //speech class creates , returns new speech engine. speechengine.audiolevelupdated += new eventhandler<audiolevelupdatedeventargs>(speechengine_audiolevelupdated); // use system's default microphone speechengine.setinputtodefaultaudiodevice(); speechengine.loadgrammar(new dictationgrammar()); // start listening speechengine.recognizeasync(recognizemode.multiple); } else { speechclass.myengine.dispose(); } } but disposal of speech obj
Read more