public partial class Form1 : Form

{

char pt = '\0'; double[] phantu = new double[2]; string kqMH = "";

public Form1()

{

InitializeComponent();

}

private void btn1_Click(object sender, EventArgs e)

{

DienSo(1);

}

private void Form1_Load(object sender, EventArgs e)

{

txthienthi.Text = "0";

}

private void btn2_Click(object sender, EventArgs e)

{

DienSo(2);

}

private void btn3_Click(object sender, EventArgs e)

{

DienSo(3);

}

private void btn4_Click(object sender, EventArgs e)

{

DienSo(4);

}

private void btn5_Click(object sender, EventArgs e)

{

DienSo(5);

}

private void btn6_Click(object sender, EventArgs e)

{

DienSo(6);

}

private void btn7_Click(object sender, EventArgs e)

{

DienSo(7);

}

private void btn8_Click(object sender, EventArgs e)

{

DienSo(8);

}

private void btn9_Click(object sender, EventArgs e)

{

DienSo(9);

}

private void btn0_Click(object sender, EventArgs e)

{

if (txthienthi.Text != "0")

txthienthi.Text += "0";

}

private void btncongtru_Click(object sender, EventArgs e)

{

kqMH = txthienthi.Text; if (kqMH.Contains("-"))

kqMH = kqMH.Replace("-", "");

else

kqMH = "-" + kqMH;

txthienthi.Text = kqMH;

}

private void btncham_Click(object sender, EventArgs e)

{

kqMH = txthienthi.Text; if (!kqMH.Contains("."))

{

kqMH += ".";

} txthienthi.Text = kqMH;

}

private void btnC_Click(object sender, EventArgs e)

{

txthienthi.Text = "0";

}

private void btncong_Click(object sender, EventArgs e)

{

phantu[0] = double.Parse(txthienthi.Text); pt = '+'; txthienthi.Text = null;

}

private void btnSqrt_Click(object sender, EventArgs e)

{

phantu[0] = double.Parse(txthienthi.Text);

pt = 's';

}

private void btnPhanTram_Click(object sender, EventArgs e)

{

phantu[0] = double.Parse(txthienthi.Text);

pt = '%';

txthienthi.Text = null;

}

private void button14_Click(object sender, EventArgs e)

{

phantu[0] = double.Parse(txthienthi.Text);

pt = '1';

}

private void btnbang_Click(object sender, EventArgs e)

{

phantu[1] = double.Parse(txthienthi.Text);

double kq = 0;

switch (pt)

{

case '+':

kq = phantu[0] + phantu[1];

break;

case '-':

kq = phantu[0] - phantu[1];

break;

case '*':

kq = phantu[0] * phantu[1];

break;

case '/':

if (phantu[1] != 0)

{

kq = phantu[0] / phantu[1];

break;

}

else

{

MessageBox.Show("Không chia du?c", "Thông báo", MessageBoxButtons.OK, MessageBoxIcon.Error);

return;

}

case 's':

kq = Math.Sqrt(phantu[0]);

break;

case '%':

kq = phantu[0] % phantu[1];

break;

case '1':

kq = 1 / phantu[0];

break;

}

txthienthi.Text = kq.ToString();

}

private void btntru_Click(object sender, EventArgs e)

{

phantu[0] = double.Parse(txthienthi.Text);

pt = '-';

txthienthi.Text = "0";

}

private void btnnhan_Click(object sender, EventArgs e)

{

phantu[0] = double.Parse(txthienthi.Text);

pt = '*';

txthienthi.Text = "0";

}

private void btnchia_Click(object sender, EventArgs e)

{

phantu[0] = double.Parse(txthienthi.Text);

pt = '/';

txthienthi.Text = "0";

}

void DienSo(int so)

{

if (txthienthi.Text == "0")

txthienthi.Text = so.ToString();

else

txthienthi.Text += so.ToString();

}

private void Form1_Load_1(object sender, EventArgs e)

{

}

}

}

bai2

public partial class Form1 : Form

{

int i = 0;

public Form1()

{

InitializeComponent();

}

private void cmdAdd_Click(object sender, EventArgs e)

{

++i;

listView1.GridLines = false;

ListViewItem item1 = new ListViewItem(i.ToString());

item1.SubItems.Add(textBox1.Text);

item1.SubItems.Add(txtDT.Text);

//Add the items to the ListView.

listView1.Items.AddRange(new ListViewItem[] { item1 });

textBox1.Text = "";

txtDT.Text = "";

}

private void Form1_Load(object sender, EventArgs e)

{

}

}

}

bai3

namespace baiso2

{

public partial class frmListBox : Form

{

public frmListBox()

{

InitializeComponent();

}

private void cmdMoveAllLeft_Click(object sender, EventArgs e)

{

}

private void cmdMoveAllRight_Click(object sender, EventArgs e)

{

lstRight.Items.Clear();

for (int i = 0; i < lstLeft.Items.Count; i++)

{

string tmp_string = lstLeft.Items[i].ToString();

lstRight.Items.Add(tmp_string);

}

lstLeft.Items.Clear(); //remove all item

}

private void cmdMoveRight_Click(object sender, EventArgs e)

{

string tmp_string = lstLeft.SelectedItem.ToString();

lstLeft.Items.Remove(lstLeft.SelectedItem);

lstRight.Items.Add(tmp_string);

}

private void cmdMoveLeft_Click(object sender, EventArgs e)

{

}

private void cmdAdd_Click(object sender, EventArgs e)

{

if (txtT1.Text.Length != 0)

{

lstLeft.Items.Add(txtT1.Text);

}

//lstLeft.Text = "Ba con ga";

txtT1.Text = null;

}

private void frmListBox_Load(object sender, EventArgs e)

{

}

}

}

bai4

namespace datagrid

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

private void Form1_Load(object sender, EventArgs e)

{

}

private void label2_Click(object sender, EventArgs e)

{

}

private void cmdLuu_Click(object sender, EventArgs e)

{

int i = dataGridDSach.RowCount-1;

dataGridDSach.Rows.Add();

dataGridDSach[0,i].Value = i;

dataGridDSach[1, i].Value = txtHoTen.Text;

dataGridDSach[2, i].Value = txtNgaySinh.Text;

dataGridDSach[3, i].Value = txtSoCMND.Text;

dataGridDSach[4, i].Value = txtDiaChi.Text;

}

private void cmdThoat_Click(object sender, EventArgs e)

{

Close();

}

private void dataGridDSach_CellContentClick(object sender, DataGridViewCellEventArgs e)

{

}

void txtSoCMND_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)

{

e.Handled = true;

if (char.IsDigit(e.KeyChar) || char.IsControl(e.KeyChar))

{

e.Handled = false;

}

// MessageBox.Show(e.KeyChar.ToString());

}

private void cmdXoa_Click(object sender, EventArgs e)

{

}

}

}