用 C# 實現截圖功能（二）：MyRectangle 核心方法實作（上）

// 以下為 MyRectangle 類別的核心方法實作片段
public int LittleRectangleWidth { get; set; }
public int LittleRectangleHeight { get; set; }
public Rectangle LeftTopRectangle { get; set; }
public Rectangle LeftMiddleRectangle { get; set; }
public Rectangle LeftBottomRectangle { get; set; }
public Rectangle RightTopRectangle { get; set; }
public Rectangle RightMiddleRectangle { get; set; }
public Rectangle RightBottomRectangle { get; set; }
public Rectangle TopMiddleRectangle { get; set; }
public Rectangle BottomMiddleRectangle { get; set; }
public Rectangle Rect 
{ 
    get { return rect; } 
    set { rect = value; x = value.X; y = value.Y; width = value.Width; height = value.Height; } 
}
public Size Size { get { return rect.Size; } }
public Image BackImage { get; set; }
public Cursor MyCursor { get; set; }

public MyRectangle()
{
    Rect = new Rectangle();
    setAllModeFalse();
    LittleRectangleWidth = 4;
    LittleRectangleHeight = 4;
    MinHeight = 5;
    MinWidth = 5;
    LeftTopRectangle = new Rectangle();
    LeftMiddleRectangle = new Rectangle();
    LeftBottomRectangle = new Rectangle();
    RightTopRectangle = new Rectangle();
    RightMiddleRectangle = new Rectangle();
    RightBottomRectangle = new Rectangle();
    TopMiddleRectangle = new Rectangle();
    BottomMiddleRectangle = new Rectangle();
    MyCursor = new Cursor(@"..\..\Cursors\hcross.cur");
}

public void SetLittleRectangle()
{
    int excursionX = LittleRectangleWidth / 2;
    int excursionY = LittleRectangleHeight / 2;
    LeftTopRectangle = new Rectangle(X - excursionX, Y - excursionY, LittleRectangleWidth, LittleRectangleHeight);
    LeftMiddleRectangle = new Rectangle(X - excursionX, Y - excursionY + Height / 2, LittleRectangleWidth, LittleRectangleHeight);
    LeftBottomRectangle = new Rectangle(X - excursionX, Y - excursionY + Height, LittleRectangleWidth, LittleRectangleHeight);
    RightTopRectangle = new Rectangle(X - excursionX + Width, Y - excursionY, LittleRectangleWidth, LittleRectangleHeight);
    RightMiddleRectangle = new Rectangle(X - excursionX + Width, Y - excursionY + Height / 2, LittleRectangleWidth, LittleRectangleHeight);
    RightBottomRectangle = new Rectangle(X - excursionX + Width, Y - excursionY + Height, LittleRectangleWidth, LittleRectangleHeight);
    TopMiddleRectangle = new Rectangle(X - excursionX + Width / 2, Y - excursionY, LittleRectangleWidth, LittleRectangleHeight);
    BottomMiddleRectangle = new Rectangle(X - excursionX + Width / 2, Y - excursionY + Height, LittleRectangleWidth, LittleRectangleHeight);
}

public void Draw(MouseEventArgs e, Color backColor)
{
    Draw(backColor);
    if (e.X < DownPointX) { Width = DownPointX - e.X; X = e.X; }
    else { Width = e.X - DownPointX; }
    if (e.Y < DownPointY) { Height = DownPointY - e.Y; Y = e.Y; }
    else { Height = e.Y - DownPointY; }
    Draw(backColor);
}

public void Draw(Color backColor)
{
    SetLittleRectangle();
    ControlPaint.DrawReversibleFrame(rect, backColor, FrameStyle.Dashed);
    ControlPaint.FillReversibleRectangle(LeftTopRectangle, Color.White);
    ControlPaint.FillReversibleRectangle(LeftMiddleRectangle, Color.White);
    ControlPaint.FillReversibleRectangle(LeftBottomRectangle, Color.White);
    ControlPaint.FillReversibleRectangle(RightTopRectangle, Color.White);
    ControlPaint.FillReversibleRectangle(RightMiddleRectangle, Color.White);
    ControlPaint.FillReversibleRectangle(RightBottomRectangle, Color.White);
    ControlPaint.FillReversibleRectangle(TopMiddleRectangle, Color.White);
    ControlPaint.FillReversibleRectangle(BottomMiddleRectangle, Color.White);
}

public void ChangeSize(MouseEventArgs e)
{
    if (!ChangeSizeMode) return;
    // 依滑鼠位置調整各邊/角，並檢查最小尺寸限制
    // 程式碼略……
}

public void Move(int newX, int newY) { X = newX; Y = newY; }

public void CheckMouseLocation(MouseEventArgs e)
{
    // 依滑鼠座標判斷落在哪個控制點或內部，設定游標與模式旗標
    // 程式碼略……
}

public void setAllModeFalse()
{
    // 將所有模式旗標設為 false，游標重設為十字
}

public bool onChangingMode()
{
    return ((MouseOnLeftTop || MouseOnLeftMiddle || MouseOnLeftBottom || MouseOnRightTop || MouseOnRightMiddle || MouseOnRightBottom || MouseOnTopMiddle || MouseOnBottomMiddle) && changeSizeMode);
}

public void Initialize(int x, int y, int width, int height)
{
    X = x; Y = y; Width = width; Height = height;
    SetLittleRectangle();
}