CODEWITHSUNDEEP
c#.netif-statementcomboboxmessagebox
anonymous
anonymous

Reputation: 29

Check if a combobox value has been selected - C# .net

I am trying to make my application better by handling exceptions. I have a form where if all the fields are not completed then show a message box to the user. Following is what I have attempted but even if all the fields are completed it still wont let me pass.

if (textBox1.Text == null || comboBox3.SelectedValue == null || 
    comboBox4.SelectedValue == null || 
    comboBox5.SelectedValue == null || comboBox8.SelectedValue == null)
{
    MessageBox.Show("Please make sure you don't have any missing fields");
}
else
{
    connection.Open();

    //update the settings to the database table 
    MySqlCommand command = connection.CreateCommand();
    // Insert into table_name values ("","name","1")
    command.CommandText = @"insert into CustomTests values ('','" + textBox1.Text + "'," + Convert.ToBoolean(checkBox1.CheckState) + ",'" + comboBox3.Text + "'," + comboBox4.Text + "," + comboBox5.Text + ",'" + comboBox8.Text + "'," + comboBox2.Text + "," + Timer_Enabled + ",'" + comboBox1.Text + "')";

    command.ExecuteNonQuery();
}

Upvotes: 1

Views: 10612

Answers (4)

Deep Patel
Deep Patel

Reputation: 45

You can try this Out also....

if (string.IsNullOrEmpty(textBox1.Text) || string.IsNullOrEmpty(this.comboBox3.Text) || string.IsNullOrEmpty(this.comboBox4.Text) ||
     string.IsNullOrEmpty(this.comboBoxSelect5.Text)|| string.IsNullOrEmpty(this.comboBox8.Text))

Upvotes: 0

Santosh Panda
Santosh Panda

Reputation: 7351

You can try this out:

if (string.IsNullOrEmpty(textBox1.Text) || comboBox3.SelectedIndex == -1 || comboBox4.SelectedIndex == -1 ||
     comboBox5.SelectedIndex == -1 || comboBox8.SelectedIndex == -1)
 {
     MessageBox.Show("Please make sure you don't have any missing fields");
 }
 else
 {
     connection.Open();

     //update the settings to the database table 
     MySqlCommand command = connection.CreateCommand();
     // Insert into table_name values ("","name","1")
     command.CommandText = @"insert into CustomTests values ('','" + textBox1.Text + "'," + Convert.ToBoolean(checkBox1.CheckState) + ",'" + comboBox3.Text + "'," + comboBox4.Text + "," + comboBox5.Text + ",'" + comboBox8.Text + "'," + comboBox2.Text + "," + Timer_Enabled + ",'" + comboBox1.Text + "')";

     command.ExecuteNonQuery();
 }

Upvotes: 3

CC Inc
CC Inc

Reputation: 5938

A TextBox's Text value is set to an empty string, "", rather than null. Next, instead of using ComboBox.SelectedValue, I would use ComboBox.SelectedIndex and check that it was not -1 (the default value if nothing is selected). 

 if (textBox1.Text == "" || comboBox3.SelectedIndex == -1 
     || comboBox4.SelectedIndex == -1 || comboBox5.SelectedIndex == -1 
     || comboBox8.SelectedIndex == -1)

Upvotes: 1

ram2013
ram2013

Reputation: 505

Don't check whether it is null or not. Check whether the length of text is greater than 0

Upvotes: 0

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