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加入小圖案目錄夾至專案
命名資料夾bmp
加入->現有項目
複選a~d四張bmp照片
宣告全域變數
private ImageList G_ImageList;
滑鼠double click專案中Properties資料夾, 選擇<資源>, <加入資源>下拉點選
<加入資源>下拉點選<加入現有檔案>
加入後如下:
========================================================================
加入控制元件ComboxBox和Button
1: private void button1_Click(object sender, EventArgs e)
2: {3: comboBox1.Items.Add("car");
4: comboBox1.Items.Add("trunk");
5: comboBox1.Items.Add("tool");
6: comboBox1.Items.Add("friend");
7: }
加入繪圖
1: private void button1_Click(object sender, EventArgs e)
2: {3: comboBox1.Items.Add("car");
4: comboBox1.Items.Add("trunk");
5: comboBox1.Items.Add("tool");
6: comboBox1.Items.Add("friend");
7: 8: //============================================================
9: comboBox1.DrawMode = DrawMode.OwnerDrawFixed;//設定繪製元素方式
10: comboBox1.DropDownStyle = //設定組合框樣式
11: ComboBoxStyle.DropDownList;12: //============================================================
13: G_ImageList = new ImageList();//建立ImageList物件
14: 15: G_ImageList.Images.Add(Properties.Resources.a); 16: G_ImageList.Images.Add(Properties.Resources.b); 17: G_ImageList.Images.Add(Properties.Resources.c); 18: G_ImageList.Images.Add(Properties.Resources.d); 19: }加入繪圖ImageList反而ComboBox項目都不見了
這是因為DrawMode已經改由OwnerDrawFixed的關係, 點選ComboBox1事件DrawItem加入繪圖功能, 框架如下
1: private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)
2: {3: if (G_ImageList != null)
4: { 5: 6: } 7: }1: private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)
2: {3: if (G_ImageList != null)
4: {5: Graphics g = e.Graphics; //得到繪圖物件
6: Rectangle rec = e.Bounds; //得到繪圖範圍
7: Size imageSize = G_ImageList.ImageSize;//取得圖像大小
8: if (e.Index >= 0) //判斷是否有繪製項
9: {10: Font font = new Font("微軟正黑體", 10, FontStyle.Bold);//建立字體物件
11: string s = comboBox1.Items[e.Index].ToString(); //得到繪製項的字串
12: DrawItemState dis = e.State;13: if (e.State == (DrawItemState.NoAccelerator | DrawItemState.NoFocusRect))
14: {15: g.FillRectangle(new SolidBrush(Color.LightBlue), rec); //畫item背景
16: G_ImageList.Draw(g, rec.Left, rec.Top, e.Index); //繪製圖像
17: e.Graphics.DrawString(s, font, new SolidBrush(Color.Black), //顯示字串
18: rec.Left + imageSize.Width, rec.Top);19: e.DrawFocusRectangle(); //顯示取得焦點時的虛線框
20: }21: else
22: {23: g.FillRectangle(new SolidBrush(Color.LightGreen), rec);//畫item背景
24: G_ImageList.Draw(e.Graphics, rec.Left, rec.Top, e.Index); //繪製圖像
25: e.Graphics.DrawString(s, font, new SolidBrush(Color.Black), //顯示字串
26: rec.Left + imageSize.Width, rec.Top);27: e.DrawFocusRectangle(); //顯示取得焦點時的虛線框
28: } 29: } 30: } 31: }執行如下
====================================================================
private bool State = false;//定義一個全局變數標識
1: private void comboBox1_KeyDown(object sender, KeyEventArgs e)
2: {3: State = (e.KeyCode != Keys.Back && e.KeyCode != Keys.Delete);//當按鍵既不是Back鍵又不是Delete鍵時
4: comboBox1.DroppedDown = true; //當有按鍵被按下時顯示下拉列表
5: }當使用者輸入字時
1: private void comboBox1_TextChanged(object sender, EventArgs e)
2: {3: if (State)
4: {5: string inputTxt = comboBox1.Text; //取得輸入的文字
6: int ind = comboBox1.FindString(inputTxt); //在ComboBox集合中搜尋匹配的文字
7: if (ind >= 0) //當有匹配時
8: {9: State = false; //關閉編輯狀態
10: comboBox1.SelectedIndex = ind; //找到對應項
11: State = true; //打開編輯狀態
12: comboBox1.Select(inputTxt.Length, comboBox1.Text.Length);//設定文字的選擇長度
13: } 14: } 15: }如果comboBox無法輸入字, 表示唯讀
記得遮蔽先前定義的DropDownStyle即可輸入
1: //comboBox1.DropDownStyle = //設定組合框樣式(變唯讀)
2: // ComboBoxStyle.DropDownList;
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