Search Results

Search found 10366 results on 415 pages for 'const char pointer'.

Page 203/415 | < Previous Page | 199 200 201 202 203 204 205 206 207 208 209 210  | Next Page >

• How to Populate a 'Tree' structure 'Declaratively'

  - by mackenir

  I want to define a 'node' class/struct and then declare a tree of these nodes in code in such a way that the way the code is formatted reflects the tree structure, and there's not 'too much' boiler plate in the way. Note that this isn't a question about data structures, but rather about what features of C++ I could use to arrive at a similar style of declarative code to the example below. Possibly with C++0X this would be easier as it has more capabilities in the area of constructing objects and collections, but I'm using Visual Studio 2008. Example tree node type: struct node { string name; node* children; node(const char* name, node* children); node(const char* name); }; What I want to do: Declare a tree so its structure is reflected in the source code node root = node("foo", [ node("child1"), node("child2", [ node("grand_child1"), node("grand_child2"), node("grand_child3" ]), node("child3") ]); NB: what I don't want to do: Declare a whole bunch of temporary objects/colls and construct the tree 'backwards' node grandkids[] = node[3] { node("grand_child1"), node("grand_child2"), node("grand_child3" }; node kids[] = node[3] { node("child1"), node("child2", grandkids) node("child3") }; node root = node("foo", kids);

  Read the article

• Compile C++ in Visual Studio

  - by Kasun

  Hi All.. I use this method to compile C++ file in VS. But even i provide the correct file it returns false. Can any one help me... This is class called CL class CL { private const string clexe = @"cl.exe"; private const string exe = "Test.exe", file = "test.cpp"; private string args; public CL(String[] args) { this.args = String.Join(" ", args); this.args += (args.Length > 0 ? " " : "") + "/Fe" + exe + " " + file; } public Boolean Compile(String content, ref string errors) { if (File.Exists(exe)) File.Delete(exe); if (File.Exists(file)) File.Delete(file); File.WriteAllText(file, content); Process proc = new Process(); proc.StartInfo.UseShellExecute = false; proc.StartInfo.RedirectStandardOutput = true; proc.StartInfo.RedirectStandardError = true; proc.StartInfo.FileName = clexe; proc.StartInfo.Arguments = this.args; proc.StartInfo.CreateNoWindow = true; proc.Start(); //errors += proc.StandardError.ReadToEnd(); errors += proc.StandardOutput.ReadToEnd(); proc.WaitForExit(); bool success = File.Exists(exe); return success; } } This is my button click event private void button1_Click(object sender, EventArgs e) { string content = "#include <stdio.h>\nmain(){\nprintf(\"Hello world\");\n}\n"; string errors = ""; CL k = new CL(new string[] { }); if (k.Compile(content, ref errors)) Console.WriteLine("Success!"); else MessageBox.Show("Errors are : ", errors); }

  Read the article

• C++ Template problem adding two data types

  - by Sara

  I have a template class with an overloaded + operator. This is working fine when I am adding two ints or two doubles. How do I get it to add and int and a double and return the double? template <class T> class TemplateTest { private: T x; public: TemplateTest<T> operator+(const TemplateTest<T>& t1)const { return TemplateTest<T>(x + t1.x); } } in my main function i have void main() { TemplateTest intTt1 = TemplateTest<int>(2); TemplateTest intTt2 = TemplateTest<int>(4); TemplateTest doubleTt1 = TemplateTest<double>(2.1d); TemplateTest doubleTt2 = TemplateTest<double>(2.5d); std::cout << intTt1 + intTt2 << /n; std::cout << doubleTt1 + doubleTt2 << /n; } I want to be able to also do this std::cout << doubleTt1 + intTt2 << /n;

  Read the article

• How to convert "0" and "1" to false and true

  - by Chris

  I have a method which is connecting to a database via Odbc. The stored procedure which I'm calling has a return value which from the database side is a 'Char'. Right now I'm grabbing that return value as a string and using it in a simple if statement. I really don't like the idea of comparing a string like this when only two values can come back from the database, 0 and 1. OdbcCommand fetchCommand = new OdbcCommand(storedProc, conn); fetchCommand.CommandType = CommandType.StoredProcedure; fetchCommand.Parameters.AddWithValue("@column ", myCustomParameter); fetchCommand.Parameters.Add("@myReturnValue", OdbcType.Char, 1). Direction = ParameterDirection.Output; fetchCommand.ExecuteNonQuery(); string returnValue = fetchCommand.Parameters["@myReturnValue"].Value.ToString(); if (returnValue == "1") { return true; } What would be the proper way to handle this situation. I've tried 'Convert.ToBoolean()' which seemed like the obvious answer but I ran into the 'String was not recognized as a valid Boolean. ' exception being thrown. Am I missing something here, or is there another way to make '1' and '0' act like true and false? Thanks!

  Read the article

• Guru of the Week 2 no match for the operator==

  - by Adam

  From Guru of the Week 2. We have the function: string FindAddr(const list<Employee> l, string name) { for( list<Employee>::const_iterator i = l.begin(); i != l.end(); i++) { if( *i == name ) // here will be compilation error { return (*i).addr; } } return ""; } I added dummy Employee class to that: class Employee { string n; public: string addr; Employee(string name) : n(name) {} Employee() {} string name() const { return n; } operator string() { return n; } }; And got compilation error: error: no match for ‘operator==’ in ‘i.std::_List_iterator<_Tp>::operator* [with _Tp = Employee]() == name’ It works only if add operator== to Employee. But, Herb Sutter wrote that: The Employee class isn't shown, but for this to work it must either have a conversion to string or a conversion ctor taking a string. But Employee has a conversion function and conversion constructor as well. GCC version 4.4.3. Compiled normally, g++ file.cpp without any flags. There should be implicit conversion and it should work, why it doesn't?

  Read the article

• How do I cover unintuitive code blocks?

  - by naivedeveloper

  For some reason, I'm having a hard time trying to cover the block of code below. This code is an excerpt from the UNIX uniq command. I'm trying to write test cases to cover all blocks, but can't seem to reach this block: if (nfiles == 2) { // Generic error routine } In context: int main (int argc, char **argv) { int optc = 0; bool posixly_correct = (getenv ("POSIXLY_CORRECT") != NULL); int nfiles = 0; char const *file[2]; file[0] = file[1] = "-"; program_name = argv[0]; skip_chars = 0; skip_fields = 0; check_chars = SIZE_MAX; for (;;) { /* Parse an operand with leading "+" as a file after "--" was seen; or if pedantic and a file was seen; or if not obsolete. */ if (optc == -1 || (posixly_correct && nfiles != 0) || ((optc = getopt_long (argc, argv, "-0123456789Dcdf:is:uw:", longopts, NULL)) == -1)) { if (optind == argc) break; if (nfiles == 2) { // Handle errors } file[nfiles++] = argv[optind++]; } else switch (optc) { case 1: { unsigned long int size; if (optarg[0] == '+' && posix2_version () < 200112 && xstrtoul (optarg, NULL, 10, &size, "") == LONGINT_OK && size <= SIZE_MAX) skip_chars = size; else if (nfiles == 2) { // Handle error } else file[nfiles++] = optarg; } break; } } } Any help would be greatly appreciated. Thanks.

  Read the article

• streaming xml pretty printer in C/C++ using expat or libxml2?

  - by Mark Zeren

  I have a library that outputs xml without whitespace all on one line. In some cases I'd like to pretty print that output. I'm looking for a BSD-ish licensed C/C++ library or sample code that will take a raw xml byte stream and pretty print it. Here's some pseudo code showing one way that I might use this functionality: void my_write(const char* buf, int len); PrettyPrinter pp(bind(&my_write)); while (...) { // ... get some more xml ... const char* buf = xmlSource.get_buf(); int len = xmlSource.get_buf_len(); int written = pp.write(buf, len); // calls my_write with pretty printed xml // ... error handling, maybe call write again, etc. ... } I'd like to avoid instantiating a DOM representation. I already have dependencies on the expat and libxml2 shared libraries, and I'd rather not add any more shared library dependencies.

  Read the article

• VC9 C1083 Cannot open include file: 'boost...' after trying to abstract an include dependency

  - by ronivek

  Hey, So I've been working on a project for the past number of weeks and it uses a number of Boost libraries. In particular I'm using the boost::dynamic_bitset library quite extensively. I've had zero issues up until now; but tonight I discovered a dependency between some includes which I had to resolve; and I tried to do so by providing an abstract callback class. Effectively I now have the following: First include... class OtherClassCallback { public: virtual int someOtherMethod() const = 0; }; class SomeClass { public: void someMethod(OtherClassCallback *oc) { ... oc->someOtherMethod(); ... } }; Second include... #include "SomeClass.h" class SomeOtherClass : public OtherClassCallback { public: int someOtherMethod() const { return this->someInt; } }; Here is the issue; ever since I implemented this class I'm now getting the following error: fatal error C1083: Cannot open include file: 'boost/dynamic_bitset/dynamic_bitset.hpp': No such file or directory Now I'm getting no other compiler errors; and it's a pretty substantial project. My include paths and so on are perfect; my files are fully accessible and removing the changes fixes the issue. Does anyone have any idea what might be going on? I'm compiling to native Windows executables in VS9. I should confess that I'm very inexperienced with C++ in general so go easy on me if it's something horribly straightforward; I can't figure it out.

  Read the article

• c++ specialized overload?

  - by acidzombie24

  -edit- i am trying to close the question. i solved the problem with boost::is_base_and_derived In my class i want to do two things. 1) Copy int, floats and other normal values 2) Copy structs that supply a special copy function (template T copyAs(); } the struct MUST NOT return int's unless i explicitly say ints. I do not want the programmer mistaking the mistake by doing int a = thatClass; -edit- someone mention classes dont return anything, i mean using the operator Type() overload. How do i create my copy operator in such a way i can copy both 1) ints, floats etc and the the struct restricted in the way i mention in 2). i tried doing template <class T2> T operator = (const T2& v); which would cover my ints, floats etc. But how would it differentiate from structs? so i wrote T operator = (const SomeGenericBase& v); The idea was the GenericBase would be unsed instead then i can do v.Whatever. But that backfires bc the functions i want wouldnt exist, unless i use virtual, but virtual templates dont exist. Also i would hate to use virtual I think the solution is to get rid of ints and have it convert to something that can do .as(). So i wrote something up but now i have the same problem, how does that differentiate ints and structs that have the .as() function template?

  Read the article

• Why do I need to close fds when reading and writing to the pipe?

  - by valentimsousa

  However, what if one of my processes needs to continuously write to the pipe while the other pipe needs to read? This example seems to work only for one write and one read. I need multi read and write void executarComandoURJTAG(int newSock) { int input[2], output[2], estado, d; pid_t pid; char buffer[256]; char linha[1024]; pipe(input); pipe(output); pid = fork(); if (pid == 0) {// child close(0); close(1); close(2); dup2(input[0], 0); dup2(output[1], 1); dup2(output[1], 2); close(input[1]); close(output[0]); execlp("jtag", "jtag", NULL); } else { // parent close(input[0]); close(output[1]); do { read(newSock, linha, 1024); /* Escreve o buffer no pipe */ write(input[1], linha, strlen(linha)); close(input[1]); while ((d = read(output[0], buffer, 255))) { //buffer[d] = '\0'; write(newSock, buffer, strlen(buffer)); puts(buffer); } write(newSock, "END", 4); } while (strcmp(linha, "quit") != 0); } }

  Read the article

• C++ trouble with pointers to objects

  - by Zibd

  I have a class with a vector of pointers to objects. I've introduced some elements on this vector, and on my main file I've managed to print them and add others with no problems. Now I'm trying to remove an element from that vector and check to see if it's not NULL but it is not working. I'm filling it with on class Test: Other *a = new Other(1,1); Other *b = new Other(2,2); Other *c = new Other(3,3); v->push_back(a); v->push_back(b); v->push_back(c); And on my main file I have: Test t; (...) Other *pointer = t.vect->at(0); delete t.vect->at(0); t.vect->erase(t.vect->begin()); if (pointer == NULL) { cout << "Nothing here.."; } // Never enters here..

  Read the article

• problem with converting simple code from Winform to silverlight app.

  - by Sara

  Hi. I have this code for window form application and I have been attempting to convert it to a Silverlight application but it does not work!. There is a Textbox and I attached KeyDown event handler to it. when the user press the arrow key ( left or right) while the focus on the textbox, it will write . or -. When it is window form i used e.KeyCode and Keys.Right and its works great but when it is silverlight I used e.Key and key.Right and the program doesn't work good because the arrows do the 2 functions moving and write ./-. How I can work this out in Silverlight? (My English not good) The code ( window form): private void textBox1_KeyDown(object sender, KeyEventArgs e) { if (sender is TextBox) { TextBox textBox = (TextBox)sender; if (e.KeyCode == Keys.Left || e.KeyCode == Keys.Right) { e.Handled = true; char insert; if (e.KeyCode == Keys.Left) { insert = '.'; } else { insert = '-'; } int i = textBox.SelectionStart; textBox.Text = textBox.Text.Insert(i, insert.ToString()); textBox.Select(i + 1, 0); } } } (and Silverlight): private void textBox1_KeyDown(object sender, KeyEventArgs e) { if (sender is TextBox) { TextBox textBox = (TextBox)sender; if (e.Key == Key.Left || e.Key == Key.Right) { e.Handled = true; char insert; if (e.Key == Key.Left) { insert = '.'; } else { insert = '-'; } int i = textBox.SelectionStart; textBox.Text = textBox.Text.Insert(i, insert.ToString()); textBox.Select(i + 1, 0); } } } I don't understand, is there huge different effect between using Keycode/Keys and Key/Key or because something else?

  Read the article

• C++: Copy contructor: Use Getters or access member vars directly?

  - by cbrulak

  Have a simple container class: public Container { public: Container() {} Container(const Container& cont) //option 1 { SetMyString(cont.GetMyString()); } //OR Container(const Container& cont) //option 2 { m_str1 = cont.m_str1; } public string GetMyString() { return m_str1;} public void SetMyString(string str) { m_str1 = str;} private: string m_str1; } So, would you recommend this method or accessing the member variables directly? In the example, all code is inline, but in our real code there is no inline code. Update (29 Sept 09): Some of these answers are well written however they seem to get missing the point of this question: this is simple contrived example to discuss using getters/setters vs variables initializer lists or private validator functions are not really part of this question. I'm wondering if either design will make the code easier to maintain and expand. Some ppl are focusing on the string in this example however it is just an example, imagine it is a different object instead. I'm not concerned about performance. we're not programming on the PDP-11

  Read the article

• insert data using sqlite issue on iphone ( not reflecting on table)

  - by prajakta

  i can insert my data but i cant show them on my table view ..i did [tableview reload data] but of no success here is my code -(void)gButtonTapped:(id)sender { NSLog(@"right nav bar button is hit%@ ",storePaths); //[self readAnimalsFromDatabase2]; appDelegate = (DatabaseTestAppDelegate *)[[UIApplication sharedApplication] delegate]; sqlite3 *database; sqlite3_stmt *compiled_statement1; if(sqlite3_open([storePaths UTF8String], &database) == SQLITE_OK) { //const char *sqlStatement = NSString *newQuery = [NSString stringWithFormat:@"insert into cat_tbl (cat_id,names,imgs) values ('12','test1','r.png')"]; // NSString *newQuery = [NSString stringWithFormat:@"select * from list_tbl"]; const char *sql = [newQuery cStringUsingEncoding:NSASCIIStringEncoding]; NSLog(@"update query is %@",newQuery); if(sqlite3_prepare_v2(database, sql, -1, &compiled_statement1, NULL) == SQLITE_OK) { int result = sqlite3_step(compiled_statement1); sqlite3_reset(compiled_statement1); NSLog(@"result %d", result); if(result != SQLITE_ERROR) { int lastInsertId = sqlite3_last_insert_rowid(database); NSLog(@"x %d", lastInsertId); } } } sqlite3_finalize(compiled_statement1); sqlite3_close(database); [tabelView reloadData];// this is also not working }

  Read the article

• Compare two variant with boost static_visitor

  - by Zozzzzz

  I started to use the boost library a few days ago so my question is maybe trivial. I want to compare two same type variants with a static_visitor. I tried the following, but it don't want to compile. struct compare:public boost::static_visitor<bool> { bool operator()(int& a, int& b) const { return a<b; } bool operator()(double& a, double& b) const { return a<b; } }; int main() { boost::variant<double, int > v1, v2; v1 = 3.14; v2 = 5.25; compare vis; bool b = boost::apply_visitor(vis, v1,v2); cout<<b; return 0; } Thank you for any help or suggestion!

  Read the article

• C++ OOP - Can you 'overload a cast' <- hard to explain in 1 sentence

  - by Brandon Miller

  Well, the WinAPI has a POINT struct, but I am trying to make an alternative class to this so you can set the values of x and y from a constructor. /** * X-Y coordinates */ class Point { public: int X, Y; Point(void) : X(0), Y(0) {} Point(int x, int y) : X(x), Y(y) {} Point(const POINT& pt) : X(pt.x), Y(pt.y) {} Point& operator= (const POINT& other) { X = other.x; Y = other.y; } }; // I have an assignment operator and copy constructor. Point myPtA(3,7); Point myPtB(8,5); POINT pt; pt.x = 9; pt.y = 2; // I can assign a 'POINT' to a 'Point' myPtA = pt; // But I also want to be able to assign a 'Point' to a 'POINT' pt = myPtB; Is it possible to overload operator= in a way so that I can assign a Point to a POINT? Or maybe some other method to achieve this? Thanks in advance.

  Read the article

• HashMap Memory Leak because of Dynamic Array

  - by Jake M

  I am attempting to create my own HashMap to understand how they work. I am using an array of Linked Lists to store the values(strings) in my hashmap. I am creating the array like this: Node** list; Instead of this: Node* list[nSize]; This is so the array can be any size at runtime. But I think I am getting a memory leak because of how I am doing this. I dont know where the error is but when I run the following simple code the .exe crashes. Why is my application crashing and how can I fix it? Note: I am aware that using a vector would be much better than an array but this is just for learning and I want to challenge myself to create the hashmap using a 'Dynamic' Array. PS: is that the correct term(Dynamic Array) for the kind of array I am using? struct Node { // to implement }; class HashMap { public: HashMap(int dynSize) { *list = new Node[dynSize]; size = dynSize; for (int i=0; i<size; i++) list[i] = NULL; cout << "END\n"; } ~HashMap() { for (int i=0; i<size; i++) delete list[i]; } private: Node** list; // I could use a vector here but I am experimenting with a pointer to an array(pointer), also its more elegant int size; }; int main() { // When I run this application it crashes. Where is my memory leak? HashMap h(5); system("PAUSE"); return 0; }

  Read the article

• std::stringstream GCC Abnormal Behavior

  - by FlorianZ

  I have a very interesting problem with compiling a short little program on a Mac (GCC 4.2). The function below would only stream chars or strings into the stringstream, but not anything else (int, double, float, etc.) In fact, the fail flag is set if I attempt to convert for example an int into a string. However, removing the preprocessor flag: _GLIBCXX_DEBUG=1, which is set by default in XCode for the debug mode, will yield the desired results / correct behavior. Here is the simple function I am talking about. value is template variable of type T. Tested for int, double, float (not working), char and strings (working). template < typename T > const std::string Attribute<T>::getValueAsString() const { std::ostringstream stringValue; stringValue << value; return stringValue.str(); } Any ideas what I am doing wrong, why this doesn't work, or what the preprocessor flag does to make this not work anymore? Thanks!

  Read the article

• C++ -- Why should we use operator -> to access member functions of a SmartPtr?

  - by q0987

  Hello all, The question is given in the last two lines of code. template<class T> // template class for smart class SmartPtr { // pointers-to-T objects public: SmartPtr(T* realPtr = 0); T* operator->() const; T& operator*() const; T* Detach( void ) { T* pData = pointee; pointee = NULL; return pData; } private: T *pointee; ... }; class TestClass {} SmartPtr<TestClass> sPtr(new TestClass); TestClass* ptrA = sPtr->Detach(); // why I always see people use this method to access member functions of a Smart pointer. We can use sPtr-> b/c we have defined operator->() in SmartPtr. TestClass* ptrB = sPtr.Detach(); // Question: Is this a valid C++ way? If not, why? Thank you

  Read the article

• How to support comparisons for QVariant objects containing a custom type?

  - by Tyler McHenry

  According to the Qt documentation, QVariant::operator== does not work as one might expect if the variant contains a custom type: bool QVariant::operator== ( const QVariant & v ) const Compares this QVariant with v and returns true if they are equal; otherwise returns false. In the case of custom types, their equalness operators are not called. Instead the values' addresses are compared. How are you supposed to get this to behave meaningfully for your custom types? In my case, I'm storing an enumerated value in a QVariant, e.g. In a header: enum MyEnum { Foo, Bar }; Q_DECLARE_METATYPE(MyEnum); Somewhere in a function: QVariant var1 = QVariant::fromValue<MyEnum>(Foo); QVariant var2 = QVariant::fromValue<MyEnum>(Foo); assert(var1 == var2); // Fails! What do I need to do differently in order for this assertion to be true? I understand why it's not working -- each variant is storing a separate copy of the enumerated value, so they have different addresses. I want to know how I can change my approach to storing these values in variants so that either this is not an issue, or so that they do both reference the same underlying variable. It don't think it's possible for me to get around needing equality comparisons to work. The context is that I am using this enumeration as the UserData in items in a QComboBox and I want to be able to use QComboBox::findData to locate the item index corresponding to a particular enumerated value.

  Read the article

• c++ STL vector is not acccepting the copy constructor

  - by prabhakaran

  I wrote a code ( c++,visual studio 2010) which is having a vector, even I though copy const is declared, but is still showing that copy const is not declared Here the code #include<iostream> #include<vector> using namespace std; class A { public: A(){cout << "Default A is acting" << endl ;} A(A &a){cout << "Copy Constructor of A is acting" << endl ;} }; int main() { A a; A b=a; vector<A> nothing; nothing.push_back(a); int n; cin >> n; } The error I got is Error 1 error C2558: class 'A' : no copy constructor available or copy constructor is declared 'explicit' c:\program files\microsoft visual studio 10.0\vc\include\xmemory 48 1 delete Anybody please help me

  Read the article

• how to Clean up(destructor) a dynamic Array of pointers??

  - by Ahmed Sharara

  Is that Destructor is enough or do I have to iterate to delete the new nodes?? #include "stdafx.h" #include<iostream> using namespace std; struct node{ int row; int col; int value; node* next_in_row; node* next_in_col; }; class MultiLinkedListSparseArray { private: char *logfile; node** rowPtr; node** colPtr; // used in constructor node* find_node(node* out); node* ins_node(node* ins,int col); node* in_node(node* ins,node* z); node* get(node* in,int row,int col); bool exist(node* so,int row,int col); //add anything you need public: MultiLinkedListSparseArray(int rows, int cols); ~MultiLinkedListSparseArray(); void setCell(int row, int col, int value); int getCell(int row, int col); void display(); void log(char *s); void dump(); }; MultiLinkedListSparseArray::MultiLinkedListSparseArray(int rows,int cols){ rowPtr=new node* [rows+1]; colPtr=new node* [cols+1]; for(int n=0;n<=rows;n++) rowPtr[n]=NULL; for(int i=0;i<=cols;i++) colPtr[i]=NULL; } MultiLinkedListSparseArray::~MultiLinkedListSparseArray(){ // is that destructor enough?? cout<<"array is deleted"<<endl; delete [] rowPtr; delete [] colPtr; }

  Read the article

• What is the purpose of the QAbstractButton::checkStateSet() method?

  - by darkadept

  I'm writing my own 4 state button and I'm not quite sure what to put in the checkStateSet() method, if anything. Here is what I've got so far: SyncDirectionButton::SyncDirectionButton(QWidget *parent) : QAbstractButton(parent) { setCheckable(true); setToolTip(tr("Click to change the sync direction")); _state = NoSync; } void SyncDirectionButton::paintEvent(QPaintEvent *e) { static QPixmapCache::Key noneKey; static QPixmapCache::Key bothKey; static QPixmapCache::Key leftKey; static QPixmapCache::Key rightKey; QPainter p(this); QPixmap pix; if (checkState() == SyncLeft) { if (!QPixmapCache::find(leftKey, &pix)) { pix.load(":/icons/sync-left.png"); leftKey = QPixmapCache::insert(pix); } } else if (checkState() == SyncBoth) { if (!QPixmapCache::find(rightKey, &pix)) { pix.load(":/icons/sync-right.png"); rightKey = QPixmapCache::insert(pix); } } else if (checkState() == SyncRight) { if (!QPixmapCache::find(bothKey, &pix)) { pix.load(":/icons/sync-both.png"); bothKey = QPixmapCache::insert(pix); } } else if (checkState() == NoSync) { if (!QPixmapCache::find(noneKey, &pix)) { pix.load(":/icons/application-exit.png"); noneKey = QPixmapCache::insert(pix); } } p.drawPixmap(0,0,pix); } SyncDirectionButton::DirectionState SyncDirectionButton::checkState() const { return _state; } void SyncDirectionButton::setCheckState(DirectionState state) { setChecked(state != NoSync); if (state != _state) { _state = state; } } QSize SyncDirectionButton::sizeHint() const { return QSize(180,90); } void SyncDirectionButton::checkStateSet() { } void SyncDirectionButton::nextCheckState() { setCheckState((DirectionState)((checkState()+1)%4)); }

  Read the article

• Problem with SqlLite database in Qt SDK 1.0.2

  - by Risino

  Hi I have a problem with SqlLite database. Here is my code: void incomeDialog::on_add_pushButton_clicked() { int a = ui->income_lineEdit->text().toInt(); int b = ui->other_lineEdit->text().toInt(); int c = (a+b); db = QSqlDatabase::addDatabase("QSQLITE"); db.setDatabaseName("money.db"); QSqlQuery query(db); query.exec("create table Income" "(Month TEXT, Payment NUMBER, Other NUMBER, Together NUMBER)"); query.prepare("INSERT INTO Income values (?,?,?,?)"); query.addBindValue(ui->comboBox->currentText()); query.addBindValue(ui->income_lineEdit->text().toInt()); query.addBindValue(ui->other_lineEdit->text().toInt()); query.addBindValue(c); query.exec(); } I use qt sdk 1.0.2. After building shows errors: Undefined reference to 'QSqlDatabase::addDatabase(QString const&, QString const&)... all errors is similar (Undefined reference to 'QSqlDatabase:: Do you have any idea how to repair it?

  Read the article

• Evaluate an expression tree

  - by Phronima

  Hi, This project that I'm working on requires that an expression tree be constructed from a string of single digit operands and operators both represented as type char. I did the implmentation and the program up to that point works fine. I'm able to print out the inorder, preorder and postorder traversals in the correct way. The last part calls for evaulating the expression tree. The parameters are an expression tree "t" and its root "root". The expression tree is ((3+2)+(6+2)) which is equal to 13. Instead I get 11 as the answer. Clearly I'm missing something here and I've done everything short of bashing my head against the desk. I would greatly appreciate it if someone can point me in the right direction. (Note that at this point I'm only testing addition and will add in the other operators when I get this method working.) public int evalExpression( LinkedBinaryTree t, BTNode root ) { if( t.isInternal( root ) ) { int x = 0, y = 0, value = 0; char operator = root.element(); if( root.getLeft() != null ) x = evalExpression(t, t.left( root ) ); if( root.getRight() != null ) y = evalExpression(t, t.right( root ) ); if( operator == '+' ) { value = value + Character.getNumericValue(x) + Character.getNumericValue(y); } return value; } else { return root.element(); } }

  Read the article

< Previous Page | 199 200 201 202 203 204 205 206 207 208 209 210  | Next Page >