http://jhlong12345.blog.163.com/blog/static/1230631292015544450189/#
結合上一篇，繼續
矩形大小的調整
還有小bug，思路有了，就行了，就不貼修改正常的代碼了，自己動動手，有思路基本都可以很快寫出來的
思路：
畫一個矩形，然后在mousedown時，判斷鼠標是否在區域內，如果在，就在四個角畫四個小正方形，然后在mousemove中判斷是否在四個方格中，如果在，就出現箭頭鼠標，然后做個標記，表示開始調整尺寸
直接看代碼吧，有點復雜了
//是否開始畫了 bool bDrawStart = false; //矩形的起始點 Point pointStart = Point.Empty; //矩形的起始點的對角點，鼠標移動點 Point pointContinue = Point.Empty; //是否要修改矩形，以鼠標點擊點在矩形內部為准，修改時自動在4個端點創建4個小方框，不能創建其他的矩形 bool bChange = false; //修改矩形時移動點的X、Y記錄，好根據它在dicPoints找到對應的矩形，或dicPointsChange找到對應小方框 Point pMove1 = Point.Empty; Point pMove2 = Point.Empty; //修改矩形時鼠標點擊進4個小方框內，確認要根據鼠標移動修改 bool bChangeMove = false; //當前全部創建的矩形的記錄 Dictionary<Point, Point> dicPoints = new Dictionary<Point, Point>(); //矩形要修改大小時4個端點創建4個小方框的記錄 Dictionary<Point, Point> dicPointsChange = new Dictionary<Point, Point>(); private void pictureBox1_MouseDown(object sender, MouseEventArgs e) { if (bDrawStart) { bDrawStart = false; } else { bDrawStart = true; pointStart = e.Location; } if (bChange) { bDrawStart = false; foreach (var item in dicPointsChange) { Point p1 = item.Key; Point p2 = item.Value; //如果在4個小框里 if ((e.Location.X > p1.X && e.Location.X < p2.X && e.Location.Y > p1.Y && e.Location.Y < p2.Y) || (e.Location.X > p2.X && e.Location.X < p1.X && e.Location.Y > p2.Y && e.Location.Y < p1.Y) || (e.Location.X > p2.X && e.Location.X < p1.X && e.Location.Y > p1.Y && e.Location.Y < p2.Y) || (e.Location.X > p1.X && e.Location.X < p2.X && e.Location.Y > p2.Y && e.Location.Y < p1.Y)) { bChangeMove = true; //p1、p2為小方框的對角點，中心點為矩形的端點,首先獲取端點， //然后根據pMove1，pMove2確定小方框在的端點是矩形的哪個端點 //最后確定起始點，起始點pointStart為移動點（鼠標點擊點、小方框在的端點）的對角點 //pointContinue為移動點（鼠標點擊點、小方框在的端點） Point p = Point.Empty; p.X = p1.X > p2.X ? p1.X - 5 : p1.X + 5; p.Y = p1.Y > p2.Y ? p1.Y - 5 : p1.Y + 5; if (p == pMove1) { pointStart = pMove2; } else if (p == pMove2) { pointStart = pMove1; } else if (p == new Point(pMove1.X, pMove2.Y)) { pointStart = new Point(pMove2.X, pMove1.Y); } else if (p == new Point(pMove2.X, pMove1.Y)) { pointStart = new Point(pMove1.X, pMove2.Y); } break; } } //如果沒點擊4個小方框，則默認放棄修改 if (!bChangeMove) { bDrawStart = true; dicPointsChange.Clear(); bChange = false; } } else { foreach (var item in dicPoints) { Point p1 = item.Key; Point p2 = item.Value; if ((e.Location.X > p1.X && e.Location.X < p2.X && e.Location.Y > p1.Y && e.Location.Y < p2.Y) || (e.Location.X > p2.X && e.Location.X < p1.X && e.Location.Y > p2.Y && e.Location.Y < p1.Y) || (e.Location.X > p2.X && e.Location.X < p1.X && e.Location.Y > p1.Y && e.Location.Y < p2.Y) || (e.Location.X > p1.X && e.Location.X < p2.X && e.Location.Y > p2.Y && e.Location.Y < p1.Y)) { bChange = true; bDrawStart = false; //不能畫新矩形了 dicPointsChange.Clear(); pMove1 = p1; pMove2 = p2; //畫出點擊矩形的4個端點的4個小方框，並記錄入dicPointsChange Graphics g = pictureBox1.CreateGraphics(); System.Drawing.Pen pen = new System.Drawing.Pen(Color.Red); g.DrawRectangle(pen, p1.X - 5, p1.Y - 5, 10, 10); g.DrawRectangle(pen, p2.X - 5, p2.Y - 5, 10, 10); g.DrawRectangle(pen, p1.X - 5, p2.Y - 5, 10, 10); g.DrawRectangle(pen, p2.X - 5, p1.Y - 5, 10, 10); pen.Dispose(); dicPointsChange.Add(new Point(p1.X - 5, p1.Y - 5), new Point(p1.X + 5, p1.Y + 5)); dicPointsChange.Add(new Point(p2.X - 5, p2.Y - 5), new Point(p2.X + 5, p2.Y + 5)); dicPointsChange.Add(new Point(p2.X - 5, p1.Y - 5), new Point(p2.X + 5, p1.Y + 5)); dicPointsChange.Add(new Point(p1.X - 5, p2.Y - 5), new Point(p1.X + 5, p2.Y + 5)); break; } } } } private void pictureBox1_MouseMove(object sender, MouseEventArgs e) { if (bDrawStart) { pointContinue = e.Location; Refresh(); } if (bChangeMove) { pointContinue = e.Location; Point p = Point.Empty; foreach (var item in dicPoints) { Point p1 = item.Key; Point p2 = item.Value; //找到dicPoints里的原始記錄 if (p1 == pointStart || p2 == pointStart || new Point(p1.X, p2.Y) == pointStart || new Point(p2.X, p1.Y) == pointStart) { p = p1; break; } } if (p != Point.Empty) { //先刪除dicPoints里的原始記錄，再根據新點創建新的記錄 dicPoints.Remove(p); dicPoints.Add(pointStart, pointContinue); dicPointsChange.Clear(); Point p1 = pointStart; Point p2 = pointContinue; //移動過程即時創建4個小方框，看起來小方框和矩形一起變大變小的效果 dicPointsChange.Add(new Point(p1.X - 5, p1.Y - 5), new Point(p1.X + 5, p1.Y + 5)); dicPointsChange.Add(new Point(p2.X - 5, p2.Y - 5), new Point(p2.X + 5, p2.Y + 5)); dicPointsChange.Add(new Point(p2.X - 5, p1.Y - 5), new Point(p2.X + 5, p1.Y + 5)); dicPointsChange.Add(new Point(p1.X - 5, p2.Y - 5), new Point(p1.X + 5, p2.Y + 5)); Refresh(); } } } private void pictureBox1_MouseUp(object sender, MouseEventArgs e) { if (bDrawStart) { //此時矩形畫完，記錄矩形兩個對角點，在Paint里畫 dicPoints.Add(pointStart, pointContinue); } if (bChangeMove) { bChangeMove = false; bChange = false; } bDrawStart = false; } private void pictureBox1_Paint(object sender, PaintEventArgs e) { System.Drawing.Pen pen = new System.Drawing.Pen(Color.LimeGreen); pen.Width = 2; if (bDrawStart) { //實時的畫矩形 Graphics g = e.Graphics; g.DrawRectangle(pen, pointStart.X, pointStart.Y, pointContinue.X - pointStart.X, pointContinue.Y - pointStart.Y); } //實時的畫之前已經畫好的矩形 foreach (var item in dicPoints) { Point p1 = item.Key; Point p2 = item.Value; e.Graphics.DrawRectangle(pen, p1.X, p1.Y, p2.X - p1.X, p2.Y - p1.Y); } if (bChangeMove) { pen.Color = Color.Red; foreach (var item in dicPointsChange) { Point p1 = item.Key; Point p2 = item.Value; e.Graphics.DrawRectangle(pen, p1.X, p1.Y, p2.X - p1.X, p2.Y - p1.Y); } } pen.Dispose(); }