[C# WinForm] Tính Cộng - Trừ - Nhân - Chia Phần mềm: Visual Studio CODE: Select All private void button1_Click(object sender, EventArgs e) { int soThuNhat = Convert.ToInt32(txta.Text); int soThuHai = Convert.ToInt32(txtb.Text); int Kq = soThuNhat + soThuHai; txtkq.Text = Kq.ToString(); } private void button2_Click(object sender, EventArgs e) { int soThuNhat = Convert.ToInt32(txta.Text); int soThuHai = Convert.ToInt32(txtb.Text); int Kq = soThuNhat - soThuHai; txtkq.Text = Kq.ToString(); } private void button3_Click(object sender, EventArgs e) { int soThuNhat = Convert.ToInt32(txta.Text); int soThuHai = Convert.ToInt32(txtb.Text); int Kq = soThuNhat * soThuHai; txtkq.Text = Kq.ToString(); } private void button4_Click(object sender, EventArgs e) { float soThuNhat = float.Parse(txta.Text); float soThuHai = float.Parse(txtb.Text); if (soThuHai == 0) { MessageBox.Show("nhap so b khac 0"); } else { float chia = soThuNhat / soThuHai; txtkq.Text = chia.ToString(); } }