integer - int? c#, used in ref, what exactly is it -

-

एक किडी, बिड्डी प्रश्न हो सकता है लेकिन

मैं एक "आउटपुट" पैरामीटर को पास करने की कोशिश कर रहा था सी शार्प का उपयोग करते हुए एक संग्रहीत कार्यविधि और जब तक मैं निम्नलिखित वाक्यविन्यास का उपयोग कर "आउटपुट" चर को पारित नहीं कर पा रहा था: 

  int? ROWID = 0; ADAPTER.INSERT (वेल 1, वैल 2, रेफरी ROWID);

हालांकि समस्या का हल हो गया है, मुझे अभी समझ में नहीं आ रहा है कि, जब मैं एक सामान्य "इंट" में मान को पकड़ने की कोशिश करता हूं, तो यह एक रूपांतरण त्रुटि देता है

<पूर्व> पूर्ण परिणाम = ROWID; // सही नहीं है

तो, मुझे क्या करना है: 

  int परिणाम = (int) ROWID; // सही

क्या वास्तव में "int?" मतलब?

int? एक nullable int है पढ़ें।

वैसे, यदि आप संपूर्ण गाइड नहीं पढ़ते हैं, तो कम से कम अपने ROWID चर पर HasValue और Value गुणों की जांच करें।


Comments

Post a Comment

Popular posts from this blog

java - Is there an object like a "Set" that can contain only unique string values, but also contain a count on the number of occurrences of the string value? -

-
There is an object like "set" in Java that can contain only unique string values, but it also includes a count Is the number of string value in number? This idea is simple. A data set, ALA ... ABBCCC I will set the text of each line set- I want to add to the object every time a non-unique text is added to the set, I also want to show a numeric value associated with the set to show how often it was added. So if I run it on the above data then set output will be something like this: A: 1B: 2C: 3 Any ideas? Maps & lt; String, integer & gt; add public null (strings) {if (map.containsKey (s)) {map.put (s, map.get (s) + 1); } And {map.put (S, 1); }}
Read more

MVP, design question -

-
I am working on an MVP designated application and there are some design questions: I presenter how to communicate while writing code in the layer Should go between different presenters / ideas? Let's say I have a window window with a window viewer and I want to set the window title on the window from the second window. I have a title-setter on the window view, which wraps the actual Gui title. Should I call the title-setter directly on the scene (window viewer.tit = "title") or should I wrap the view title as the presentation title setter (window-creator.tit = "title")? Ask yourself how you will test it? If you do a window presentation. View. Tight = "Title", how can you test that the presenter is setting the title?
Read more