c# - Getting a NullpointerException on my code -

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मुझे इस कोड पर एक Nullpointer मिल रहा है: 

  सार्वजनिक शून्य InsertImportantMsg (स्ट्रिंग msg, डेटटाइम टूडे, इंट दृश्य) {connection.Open (); स्ट्रिंग क्वेरी = "अपडेट करें IMPORTANTMESSAGE SET MESSAGES = ': msg', DATETIME = ': toDay'," + "LABELVISIBILITY = ': दृश्यमान'"; Connection.CreateCommand (); Cmd.CommandText = query; Cmd.Parameters.Add (": msg", msg); Cmd.Parameters.Add (": toDay", आज); Cmd.Parameters.Add (": दिखाई", दृश्यमान); Cmd.ExecuteNonQuery (); }

विशेष रूप से इस रेखा पर: 

  cmd.CommandText = query;

मैं पैरामीटर सही पास कर रहा हूँ क्या मेरे अपडेट स्टेटमेंट में कुछ गड़बड़ है, मुझे पता नहीं है?

(मुझे पता है कि कोड को पकड़ने की कोशिश में होना चाहिए, लेकिन यह अभी भी उद्देश्य पर है, इसलिए इसे न देखें) < / P>

धन्यवाद

अपवाद का तत्काल कारण यह है कि आप haven ' टी असाइन किया गया सीएमडी मान। कार्यान्वयन ऐसा हो सकता है कि 

  सार्वजनिक शून्य InsertImportantMsg (स्ट्रिंग msg, दिनांकटाइम toDay, int दृश्यमान) {connection.Open (); // उपयोग करने में IDisposable रखें ... (var cmd = connection.CreateCommand ()) {// पढ़ने योग्य सीएमडी के लिए क्वेरी की क्वेरी करें। कॉमांड टेक्स्ट = @ "अद्यतन IMPORTANTMESSAGE SET MESSAGES =: msg, - & lt; - आप डॉन ' टी यहाँ apostrophes की जरूरत है ... DATETIME =: toDay, LABELVISIBILITY =: दृश्यमान "; Cmd.Parameters.Add (": msg", msg); Cmd.Parameters.Add (": toDay", आज); // TODO: यह चेक करें - ओरेकल बूलीयन का समर्थन नहीं करता है SQL cmd.Parameters.Add (": दिखाई", दृश्यमान); cmd.ExecuteNonQuery (); }}

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