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问题 I am filling a 10 x 10 grid of characters from an input file. I need to check if the grid is a square (i.e, has N x N characters, where N <= 10) The input file is such: pitk olpe pkey tope When I print the grid in gdb, I get the following result: $1 = {"pitk\000\000\000\000\366h", "olpe\000\000\001\000\000", "pkey\000\000\000\000\000", "tope\000\000\000\000\000", "\000\344\241\367\377\177\000\000", <incomplete sequence \336>, "\000\377\377\177\000\000\037\355\336", <incomplete sequence \367>,

问题 I get the following error: undefined method `[]' for nil:NilClass The related snippet in line 50: 47: <%=h @contact.date_entered.to_date %></br> 48: Next event: 49: <% next_delayed_todo = @contact.next_delayed_todo %> 50: <% unless next_delayed_todo[:event].nil? %> 52: <%= next_delayed_todo[:event].title %> </br> 回答1: See how you have 3 consecutive lines of nothing but code in your view? That's a sign you should pull it out into a helper, in order to keep your views clean. New view code: <%=h

问题 This question already has answers here : What is a NullPointerException, and how do I fix it? (12 answers) Closed 2 years ago . My insert function public void AddBakim(){ btn_bakimkaydet.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { db.insertBakim("1","2","3"); } }); } My database function public boolean insertBakim(String bAd,String bFiyat,String bTarih){ /*String FK_aID*/ SQLiteDatabase db = this.getWritableDatabase(); ContentValues deger = new

问题 I am trying to see if a user has made a purchase by retrieving the NSUserDefaults value for each product identifier. I save the value when a product is purchased and it is getting set correctly. The key-value pair show up correctly when calling this: NSLog(@"%@", [[NSUserDefaults standardUserDefaults] dictionaryRepresentation]); As this: "com.COMPANY.PRODUCTIDENTIFIER" = 1; But when I try to actually validate that specific key-value it always returns null: for (NSString * productIdentifier in

问题 I'm reworking a Rails 2 website. Right now, I'm getting an error, and I think it's because a value is being submitted as blank instead of .nil. However, my attempts to keep it nil don't seem to be working. I appreciate any help you have to offer. From Model, based on Make blank params[] nil NULL_ATTRS = %w( start_masterlocation_id ) before_save :nil_if_blank protected def nil_if_blank NULL_ATTRS.each { |attr| self[attr] = nil if self[attr].blank? } end View I've got jQuery that adds a value

问题 I'm working on an application in VB6. I came across what seems to be a small issue, however it is annoying and I am unable to fix it. What I'm doing is trying to pass 2 values to a function.... Private Sub cmdSearch2P_Click() Call AxisSearch(2, cboDiagId) End Sub This is the function I'm passing it to... Private Sub AxisSearch(plngAxis As Long, pcbo As ComboBox) What's happening is cboDiagID is a NULL value which the function does not accept. In order for it to work, it needs to be "". I don

问题 This question already has answers here : Cannot retrieve field values from realm object, values are null in debugger (3 answers) Closed 2 years ago . There are my models: public class RChat extends RealmObject { @PrimaryKey private String Id; private RMyTest Test; public RChat() {} } and public class RMyTest extends RealmObject { @PrimaryKey private String myName; public RMyTest() { } } And I'm using like this: mRealm = Realm.getInstance(this); mRealm.beginTransaction(); final RChat chat =

问题 I wish to enable automatic login to my app, yet the problem that is arising is that the service is being started and bound after the automatic login features are being called: 04-28 20:21:09.061 5427-5427/com.example.feastapp I/PersonaManager﹕ getPersonaService() name persona_policy 04-28 20:21:09.081 5427-5427/com.example.feastapp V/AUTO LOGIN TEST﹕ Waiting... 1/5 @ 268919454 04-28 20:21:14.086 5427-5427/com.example.feastapp V/AUTO LOGIN TEST﹕ Waiting... 2/5 @ 268924454 04-28 20:21:19.081

问题 I have a class that contains file handle fHandle that points to an open file. Now, it can be closed by any one of the multiple routines and that is based on dynamic run of the program. To be sure that a file is indeed closed, I put simple snippet in my destructor: if(fHandle!=NULL) fclose(fHandle); . Turns out, if one of the routines had previously closed this file, then the running the destructor snippet causes double free operation and I get **glib detected** error message. How do I make

问题 I am trying to concatenate files using cmake and append a null character( \0 ) at the end of output file. Does anyone know how to append null at the end? The code for concat is : function(cat in_file1 in_file2 out_file) file(READ ${in_file1} CONTENTS) file(WRITE ${out_file} "${CONTENTS}") file(READ ${in_file2} CONTENTS) file(APPEND ${out_file} "${CONTENTS}") endfunction() To append '\0' at the end I've tried following approaches : file(APPEND ${out_file} NULL) file(APPEND ${out_file} "\\0")