Role Based User Login with Switch Case in Windows App in C#

Hemal Joshi

Hello,

I have created a Role Based Login form in Windows Form Application in C# there i have used switch case for selecting role.

When i am run the form and enter Username and Password worng it will not go to the default block of the switch case so help me and give me an example of role based login form in windows application.

Design:

Code:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

using System.Data.SqlClient;

namespace DemoLogin

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

private void button1_Click(object sender, EventArgs e)

{

SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\admin\Documents\DemoCon.mdf;Integrated Security=True;Connect Timeout=30");

SqlDataAdapter da = new SqlDataAdapter("select Type from Login where Username='" + textBox1.Text +"' and Password='" + textBox2.Text + "'",con);

DataTable dt = new DataTable();

da.Fill(dt);

if (dt.Rows.Count == 1)

{

switch (dt.Rows[0]["Type"] as string)

{

case "Admin":

{

this.Hide();

new HomeMenus().Show();

break;

}

case "User":

{

MessageBox.Show("You are User and only view the things");

break;

}

case "Other":

{

new Others().Show();

break;

}

default:

{

MessageBox.Show("Enter Correct Username and Password");

break;

}

textBox1.Text = "";

textBox2.Text = "";

}

private void button2_Click(object sender, EventArgs e)

{

this.Close();

}

Database:

8 Replies

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Dharmraj Thakur8y ago
Simple yaar, If now rows found then show the error message to user
0
Hemal Joshi8y ago
Database:

But Brother I want to generate error when i enter Username: Admin and Password: Admin will not match with database it will raise an error same as other Two data if i will enter wrong Username: User and Password: User it will raised and error and if i entered correct Username and Password according to database it logged in successfully.
+1
Dharmraj Thakur8y ago
Just add these keyword in your query...
select Type from Login
where Username='admin' and Password='admin' COLLATE Latin1_General_CS_AS
0
Hemal Joshi8y ago
Brother it's working perfectly but i want to know that if database Usernm:Admin and Pass:admin then at run time i have enter Usernm:admin and Pass:admin then it will take the data is matching with database and login success but here my point is these at run time both data are different from db then why it should login it will generate an error don't you.

How can i generate it help me.
+1
Dharmraj Thakur8y ago
Is it throwing any error? if yes then show me error...
0
Hemal Joshi8y ago
Bhai Application run thay pachi hu Username:Admin and Pass:admin enter karu to j next form open thavu joy ok but hu Username:admin and Pass:admin enter karu to pan login thay 6 e rite na thavu joy ne.

Then i click login it will accept as successful and move to next form as under

Now my question is when username and pass are not same then why it will accept login and move to next.

Are you now understand better...
+1
Dharmraj Thakur8y ago
You are facing problem because if no any record match in database it means DataTable has row count 0. So your code not able to satisfy if condition...

Just add the else part in you if condition...

else
{
MessageBox.Show("Enter Correct Username and Password");
}

So code will look like...
if (dt.Rows.Count == 1)
{
    switch (dt.Rows[0]["Type"] as string)
    {
        case "Admin":
            {
                this.Hide();
                new HomeMenus().Show();
                break;
            }
        case "User":
            {
                MessageBox.Show("You are User and only view the things");
                break;
            }
        case "Other":
            {
                new Others().Show();
                break;
            }
        default:
            {
                MessageBox.Show("Enter Correct Username and Password");
                break;
            }
    }
    textBox1.Text = "";
    textBox2.Text = "";
}
else
{
    MessageBox.Show("Enter Correct Username and Password");
}
0
Ramesh Palanivel8y ago
Hi Hemal,

Try this code,
private void button1_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\admin\Documents\DemoCon.mdf;Integrated Security=True;Connect Timeout=30");
SqlCommand da = new SqlCommand("select Type from Login where Username='" + textBox1.Text +"' and Password='" + textBox2.Text + "'",con);
SqlDataReader reader=cmd.ExecuteReader();
if (reader.hasRows)
{
switch (reader[0]["Type"].toString())
{
case "Admin":
{
this.Hide();
new HomeMenus().Show();
break;
}
case "User":
{
MessageBox.Show("You are User and only view the things");
break;
}
case "Other":
{
new Others().Show();
break;
}
default:
{
MessageBox.Show("Enter Correct Username and Password");
break;
}
}
textBox1.Text = "";
textBox2.Text = "";
}
}
private void button2_Click(object sender, EventArgs e)
{
this.Close();
}
}
}
+1