做完四個小專案的收穫
阿新 • • 發佈:2018-12-31
一、員工資訊管理系統
1)繫結下拉列表的知識
1 private void Form1_Load(object sender, EventArgs e) 2 { 3 string sql = "select * from DeptInfo"; 4 this.comboBox1.DataSource = s.CHA(sql); 5 this.comboBox1.DisplayMember = "Deptname"; 6 this.comboBox1.ValueMember = "DeptID"; 7 int ID = int.Parse(this.comboBox1.SelectedValue.ToString()); 8 }
2)驗證輸入框中輸入的數字
1 foreach (char chr in this.txtAeg.Text) 2 { 3 if(char.IsDigit(chr)) 4 { 5 } 6 else{MessageBox.Show("年齡只能為整數型別");return;}; 7 }
二、圖書管理系統
1)初始化時間,統計表中的行數
1 //初始化時的資料 2 private void groupBox1_Enter(object sender, EventArgs e) 3 { 4 string sql = "select BookID,BookName,BookAuthor,BookConcert,BookDates,BookCount,TypeName from TblBookInfo
inner join TblBookType on TblBookInfo.BookTypeID=TblBookType.ID"; 5 dataGridView1.DataSource = S.CHA(sql); 6 this.label3.Text = "共有 " + (dataGridView1.RowCount-1).ToString() + " 條資料"; 7 this.label2.Text = "當前時間為:" + DateTime.Now.ToString(); 8 timer1.Start(); 9 }
2)精確查詢和模糊查詢,發揮到極致(用拼接)
1 //選擇精確查詢或模糊查詢 2 string tiaojian = this.textBox1.Text;//預設精確 3 if (radioButton2.Checked) 4 { 5 tiaojian = "%" + this.textBox1.Text + "%"; 6 } 7 //查詢的欄位:編號,書名,作者,型別 8 string ziduan = ""; 9 switch (comboBox1.SelectedIndex) 10 { 11 case 0: 12 ziduan = "BookID like'" + tiaojian +"'"; 13 break; 14 case 1: 15 ziduan = "BookName like'" + tiaojian + "'"; 16 break; 17 case 2: 18 ziduan = "BookAuthor like'" + tiaojian + "'"; 19 break; 20 case 3: 21 ziduan = "TypeName like'" + tiaojian + "'"; 22 break; 23 } 24 string sql = "select BookID,BookName,BookAuthor,BookConcert,BookDates,BookCount,TypeName from TblBookInfo
inner join TblBookType on TblBookInfo.BookTypeID=TblBookType.ID where "+ziduan; 25 dataGridView1.DataSource = S.CHA(sql); 26 this.label3.Text = "共有 " + (dataGridView1.RowCount - 1).ToString() + " 條資料"; 27 }
三、簡易的銷售管理系統
1)時間的模糊查詢
1 if (radioButton3.Checked) 2 { 3 //獲得,年,月,日 4 string r1 = dateTimePicker3.Value.ToShortDateString(); 5 string r2 = dateTimePicker2.Value.ToShortDateString(); 6 //日期的模糊查詢 7 sqlc = string.Format("select * from biao2 where riqi>='{0}' and riqi<='{1}'", r1,r2); 8 }
2)控制元件是否能使用
1 //載入時 2 private void Form3_Load(object sender, EventArgs e) 3 { 4 this.textBox3.ReadOnly = true; 5 this.dateTimePicker3.Enabled = false; 6 this.dateTimePicker2.Enabled = false; 7 }
四、學員資訊管理系統
1)執行程式後過一段時間開啟另一個窗體
1 //載入時開啟計時器 2 private void Form1_Load(object sender, EventArgs e) 3 { 4 timer1.Start(); 5 } 6 //調計時器的Interval屬性,每兩秒執行一次 7 private void timer1_Tick(object sender, EventArgs e) 8 { 9 frmxx f = new frmxx(); 10 f.Show(); //開啟另一個窗體 11 timer1.Stop(); //然後關掉計時器 12 }
2)第一條,上一條,下一條,最後一條
1 //上一條,下一條 2 public void xiayi(int i) 3 { 4 this.comboBox1.SelectedIndex = i; //返回或設定哪個選項被選取,組合框現行選中項,索引 5 //根據索引,和列取得表中的值 6 this.textBox2.Text = this.dataGridView1.Rows[i].Cells[1].Value.ToString(); 7 this.textBox3.Text = this.dataGridView1.Rows[i].Cells[2].Value.ToString(); 8 this.textBox4.Text = this.dataGridView1.Rows[i].Cells[6].Value.ToString(); 9 this.textBox5.Text = this.dataGridView1.Rows[i].Cells[7].Value.ToString(); 10 this.textBox6.Text = this.dataGridView1.Rows[i].Cells[3].Value.ToString(); 11 this.textBox7.Text = this.dataGridView1.Rows[i].Cells[5].Value.ToString(); 12 this.textBox8.Text = this.dataGridView1.Rows[i].Cells[4].Value.ToString(); 13 } 14 //第一條 15 private void button2_Click(object sender, EventArgs e) 16 { 17 xiayi(0);//索引為0 18 } 19 //最後一條 20 private void button5_Click(object sender, EventArgs e) 21 { 22 //先獲得表中的行數,減去一個無資料行,索引從0開始的所以再減一 23 int z = dataGridView1.Rows.Count-2; 24 xiayi(z); 25 } 26 //上一條 27 private void button3_Click(object sender, EventArgs e) 28 { 29 //上一條,也就是索引減一 30 int i = this.comboBox1.SelectedIndex-1; 31 //當索引減到小於0時,將索引賦值為最大 32 if (i<0) 33 { 34 i = dataGridView1.Rows.Count-2; 35 } 36 xiayi(i); 37 } 38 //下一條 39 private void button4_Click(object sender, EventArgs e) 40 { 41 int i = this.comboBox1.SelectedIndex + 1; 42 //當索引增加到最大值時,將索引賦值為0 43 if (i > dataGridView1.Rows.Count - 2) 44 { 45 i = 0; 46 } 47 xiayi(i); 48 }