패널 컨트롤 안에 둘 이상의 드래그 가능한 선 그리기

Question

namespace DraggableControls 
{ 
    public partial class Form1 : Form 
    { 
     public Form1() 
     { 
      InitializeComponent(); 
     } 

     private Control activeControl; 
     private Point previousLocation; 

     void txt1_MouseDown(object sender, MouseEventArgs e) 
     { 
      activeControl = sender as Control; 
      previousLocation = e.Location; 
      Cursor = Cursors.Hand;    
     } 
     void txt1_MouseUp(object sender, MouseEventArgs e) 
     { 
      activeControl = null; 
      Cursor = Cursors.Default; 
     } 
     void txt1_MouseMove(object sender, MouseEventArgs e) 
     { 
      if (activeControl == null || activeControl != sender) 
       return; 
      Point location = activeControl.Location; 
      location.Offset(e.Location.X - previousLocation.X, 
          e.Location.Y - previousLocation.Y); 
      activeControl.Location = location; 
      DrawLine(txt1.Location, txt2.Location, panel1); 
     } 

     private void Form1_Load(object sender, EventArgs e) 
     { 
      txt1.MouseDown += new MouseEventHandler(txt1_MouseDown); 
      txt1.MouseMove += new MouseEventHandler(txt1_MouseMove); 
      txt1.MouseUp += new MouseEventHandler(txt1_MouseUp); 


      txt3.MouseDown += new MouseEventHandler(txt3_MouseDown); 
      txt3.MouseMove += new MouseEventHandler(txt3_MouseMove); 
      txt3.MouseUp += new MouseEventHandler(txt3_MouseUp); 
     } 



     void txt3_MouseDown(object sender, MouseEventArgs e) 
     { 
      activeControl = sender as Control; 
      previousLocation = e.Location; 
      Cursor = Cursors.Hand; 
     } 
     void txt3_MouseUp(object sender, MouseEventArgs e) 
     { 
      activeControl = null; 
      Cursor = Cursors.Default; 
     } 
     void txt3_MouseMove(object sender, MouseEventArgs e) 
     { 
      if (activeControl == null || activeControl != sender) 
       return; 
      Point location = activeControl.Location; 
      location.Offset(e.Location.X - previousLocation.X, 
          e.Location.Y - previousLocation.Y); 
      activeControl.Location = location; 
      DrawLine(txt3.Location, txt4.Location, panel1); 
     } 

     public void DrawLine(Point start, Point end, Panel ctrl) 
     { 
      ctrl.Refresh(); 
      Pen P = new Pen(Color.Red, 3); 
      P.StartCap = System.Drawing.Drawing2D.LineCap.NoAnchor; 
      P.CustomEndCap = 
       new System.Drawing.Drawing2D.AdjustableArrowCap(4, 8, false); 
      ctrl.CreateGraphics().DrawLine(P, start, end); 
      ctrl.PerformLayout(); 
      ctrl.CreateGraphics().Dispose(); 
     } 
    } 
} 

드래그 가능한 드래그 가능한 텍스트 상자를 그리고 두 개의 텍스트 상자를 연결하고자합니다. 이 코드에서는 TextBox를 끌 수 있지만 두 줄 사이의 링크가 제대로 작동하지 않습니다.

Answer 1

• DrawLine 코드는 잘못된 및/또는 귀하의 코드가 여기에

는 제안이다 상당히 중복 Dispose 및

누락 된 꺼져; 최초의 적절한 using 조항 : 제외

public void DrawLine(Point start, Point end, Control ctrl) 
    { 
     ctrl.Refresh(); 
     using (Graphics g = activeControl.CreateGraphics()) 
     using (Pen P = new Pen(Color.Red, 3)) 
     { 
      P.StartCap = System.Drawing.Drawing2D.LineCap.NoAnchor; 
      P.CustomEndCap = 
      new System.Drawing.Drawing2D.AdjustableArrowCap(4, 8, false); 
      g.DrawLine(P, start, end); 
     } 
    } 

으로 DrawLine 코드를 정리하자 : 이것은 당신이 control.CreateGraphics()을 사용하고자하는 드문 경우 중 하나입니다 참고; 마지막으로

void txt_MouseDown(object sender, MouseEventArgs e) 
{ 
    activeControl = sender as Control; 
    previousLocation = e.Location; 
    Cursor = Cursors.Hand; 
} 

void txt_MouseUp(object sender, MouseEventArgs e) 
{ 
    activeControl = null; 
    Cursor = Cursors.Default; 
    panel1.Invalidate(); 
} 

void txt_MouseMove(object sender, MouseEventArgs e) 
{ 
    if (activeControl == null || activeControl != sender) 
     return; 
    Control tgtCtl = activeControl.Tag as Control; // check the.. 
    if (tgtCtl == null) return;      // target! 

    Point location = activeControl.Location; 
    location.Offset(e.Location.X - previousLocation.X, 
        e.Location.Y - previousLocation.Y); 
    activeControl.Location = location; 

    DrawLine(location, tgtCtl.Location, activeControl.Parent); 
} 

:

다음의 제네릭 마우스 이벤트를 만들어 보자 .. 결과 그래픽은 시스템이 양식을 다시 그려 whener가 사라집니다 즉, 비 영구적입니다,하지만 우리가 여기서 원하는 것입니다 우리는 후킹 같은 일반적인 이벤트에 모두TextBoxes 및 설정하여 다른 TextBox이 대상이 될 것이다, 각각의 이야기에 의해 준비의 Tag :

private void Form1_Load(object sender, EventArgs e) 
{ 
    txt1.Tag = txt2; 
    txt3.Tag = txt4; 

    txt1.MouseDown += new MouseEventHandler(txt_MouseDown); 
    txt1.MouseMove += new MouseEventHandler(txt_MouseMove); 
    txt1.MouseUp += new MouseEventHandler(txt_MouseUp); 

    txt3.MouseDown += new MouseEventHandler(txt_MouseDown); 
    txt3.MouseMove += new MouseEventHandler(txt_MouseMove); 
    txt3.MouseUp += new MouseEventHandler(txt_MouseUp); 

    .. 
    } 

activeControl.Parent에 그림을 그려서 Panel을 어떻게 만들 었는지 주목하십시오.