Please how can i validate this block

Question

private void button1_Click(object sender, EventArgs e)
        {


           resultBindingSource1.DataSource = from result in ds.Results where result.REGISTRATION_NUMBER == textBox1.Text && result.EXAM_YR == comboBox1.SelectedItem select result;



        }

The above code works perfectly when i click button1 to to filter the datasource.

Please i need an error message box to pop up if the textbox and combobox are empty or the values are incorrect

Thanks

Christian Nwamba · Answer

Thanks. It keeps displaying enter details even when i have entered the parameters.

Sanjeeb Lenka · Answer

try like this private void button1_Click(object sender EventArgs e) { if(textBox1.Text!=String.Empty && comboBox1.SelectedText!=String.Empty) { var res = from result in ds.Results where result.REGISTRATION_NUMBER == textBox1.Text && result.EXAM_YR == comboBox1.SelectedItem select result; if(res!=null) resultBindingSource1.DataSource=res; else MessageBox.Show(no data found); } else { MessageBox.Show(Enter details); } }

Christian Nwamba · Answer

Sanjeeb What if if the values entered were not found in the database. Thanks for your help

Sanjeeb Lenka · Answer

try like this private void button1_Click(object sender EventArgs e) { if(textBox1.Text!=String.Empty && comboBox1.SelectedText!=String.Empty) { resultBindingSource1.DataSource = from result in ds.Results where result.REGISTRATION_NUMBER == textBox1.Text && result.EXAM_YR == comboBox1.SelectedItem select result; } else { MessageBox.Show(Enter details); } }