//Load all answer in sql server
public List<Answer> ListAll()
{
List<Answer> list = new List<Answer>();
//connect to DB
SqlConnection con = new SqlConnection();
con.ConnectionString = conStr;
con.Open();
//Select all topics
string sql = "SELECT * FROM Answers";
SqlCommand cmd = new SqlCommand();
cmd.CommandText = sql;
cmd.Connection = con;
//execute
SqlDataReader dr = cmd.ExecuteReader();
//add to list
while (dr.Read())
{
//create topic
Answer a = new Answer();
a.Code = (int)dr["AnswerCode"];
a.QCode = (int)dr["QuestionCode"];
a.Text = dr["Text"].ToString();
a.IsCorrect = (bool)dr["IsCorrect"];
//add to list
list.Add(a);
}
dr.Close();
con.Close();
return list;
}
//Add an answer to sql server
public bool Add(Answer a)
{
//connect to DB
SqlConnection con = new SqlConnection();
con.ConnectionString = conStr;
con.Open();
//save t into DB
string sql = "INSERT INTO Answers (AnswerCode, QuestionCode, Text, IsCorrect) "+
"VALUES (@AnswerCode, @QuestionCode, @Text, @IsCorrect)";
SqlCommand cmd = new SqlCommand();
cmd.CommandText = sql;
cmd.Connection = con;
//define query parameters
cmd.Parameters.Add("AnswerCode", SqlDbType.Int);
cmd.Parameters.Add("QuestionCode", SqlDbType.Int);
cmd.Parameters.Add("Text", SqlDbType.NVarChar);
cmd.Parameters.Add("IsCorrect", SqlDbType.Bit);
//set value to parameters
cmd.Parameters["AnswerCode"].Value = a.Code;
cmd.Parameters["QuestionCode"].Value = a.QCode;
cmd.Parameters["Text"].Value = a.Text;
cmd.Parameters["IsCorrect"].Value = a.IsCorrect;
//execute query
int ret=cmd.ExecuteNonQuery();
con.Close();
//return success status
return ret == 1;
}
//Make a question from input information
public Question input()
{
TextBox[] txtAnswers = { txtAnswerA, txtAnswerB, txtAnswerC, txtAnswerD, txtAnswerE, txtAnswerF };
CheckBox[] ckbAnswers = { ckbAnswerA, ckbAnswerB, ckbAnswerC, ckbAnswerD, ckbAnswerE, ckbAnswerF };
answerList = new List<Answer>();
Question q = new Question();
Answer a;
try
{
for (int i = 0; i < 6; i++)
{
a = new Answer();
if (txtAnswers[i].Text.Equals("") == false)
{
a.Code = Convert.ToInt32(txtCode.Text)*10+i;
a.QCode = Convert.ToInt32(txtCode.Text);
a.Text = txtAnswers[i].Text;
a.IsCorrect = ckbAnswers[i].Checked;
answerList.Add(a);
}
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
//check input
if (checkInput() != false)
{
q.Code = Convert.ToInt32(txtCode.Text);
q.Text = (txtQuestion).Text;
q.Mark = Convert.ToDouble(txtMark.Text);
q.Topic = cbbTopic.Text;
q.Answers = answerList;
if (image != null)
{
q.Image = ImageToByte(image);
}
else
q.Image = null;
return q;
}
return null;
}