C# Graphics.DrawLine()方法用法及代碼示例

Graphics.DrawLine()方法用於繪製連接由坐標對指定的兩個點的線。此方法的重載列表中有4種方法，如下所示：

DrawLine(Pen, PointF, PointF) Method

DrawLine(Pen, Int32, Int32, Int32, Int32) Method

DrawLine(Pen, Single, Single, Single, Single) Method

DrawLine(Pen, Point, Point) Method

在這裏，我們將討論前兩種方法。

DrawLine(Pen, PointF, PointF) Method

此方法用於繪製從一組指定的點到一組指定的點的線形。它需要一個PointF變量，該變量由(x，y)點組成。

用法:

public void DrawLine (System.Drawing.Pen pen, System.Drawing.PointF pt1, System.Drawing.PointF pt2);

參數：

pen:筆確定線條的顏色，寬度和樣式。
pt1:將(x，y)坐標定義為初始點的PointF變量。
pt2:將(x，y)坐標定義為最終點的PointF變量。

異常：如果pen為null，則此方法將提供ArgumentNullexception。

例：

// C# program to demonstrate the  
// DrawLine(Pen, PointF, PointF) Method 
using System; 
using System.Drawing; 
using System.Drawing.Printing; 
using System.Windows.Forms; 
  
namespace GFG { 
  
class PrintableForm:Form { 
  
    public static void Main() 
    { 
        Application.Run(new PrintableForm()); 
    } 
  
    public PrintableForm() 
    { 
        ResizeRedraw = true; 
    } 
    protected override void OnPaint(PaintEventArgs pea) 
    { 
        // Defines pen 
        Pen pen = new Pen(ForeColor); 
  
        // Defines the both points to connect 
        // pt1 is (30.0, 30.0) which represents (x1, y1) 
        PointF pt1 = new PointF(30.0F, 30.0F); 
  
        // pt2 is (200.0, 300.0) which represents (x2, y2) 
        PointF pt2 = new PointF(200.0F, 300.0F); 
  
        // Draws the line 
        pea.Graphics.DrawLine(pen, pt1, pt2); 
    } 
} 
}

輸出：

DrawLine(Pen, Int32, Int32, Int32, Int32) Method

此方法用於繪製線形式的一組指定坐標，這些坐標以離散形式x1，y1，x2，y2給出。

用法:

public void DrawLine (System.Drawing.Pen pen, int x1, int y1, int x2, int y2);

參數：

pen：Pen確定線條的顏色，寬度和樣式。
x1：第一點的橫坐標。
y1：第一點的縱坐標。
x2：第二點的橫坐標。
y2：第二點的縱坐標。

異常：如果pen為null，則此方法將提供ArgumentNullexception。

範例1：

// C# program to draw a cross using the 
// DrawLine(Pen, Int32, Int32, Int32, 
// Int32) Method 
using System; 
using System.Drawing; 
using System.Drawing.Printing; 
using System.Windows.Forms; 
  
namespace GFG { 
  
class PrintableForm:Form { 
  
    public static void Main() 
    { 
        Application.Run(new PrintableForm()); 
    } 
  
    public PrintableForm() 
    { 
        ResizeRedraw = true; 
    } 
  
    protected override void OnPaint(PaintEventArgs pea) 
    { 
        // Defines the pen 
        Pen pen = new Pen(ForeColor); 
  
        // To draw a cross we need to make 2  
        // diagonals from top-left to the  
        // bottom-right and top-right to the  
        // bottom-left to calculate these  
        // coordinates we would take help of  
        // our screen size top-left = (0, 0) 
        // bottom-right = (ClientSize.Width - 1, 
        // ClientSize.Height - 1) 
        // top-right = (ClientSize.Width - 1, 0) 
        // bottom-left = (0, ClientSize.Height - 1) 
        pea.Graphics.DrawLine(pen, 0, 0, ClientSize.Width - 1, 
                                       ClientSize.Height - 1); 
  
        pea.Graphics.DrawLine(pen, ClientSize.Width - 1, 0, 0, 
                                       ClientSize.Height - 1); 
    } 
} 
}

輸出：

範例2：

// C# program to Create a 8x8 square board 
// using // DrawLine(Pen, Int32, Int32, Int32, 
// Int32) Method 
using System; 
using System.Drawing; 
using System.Drawing.Printing; 
using System.Windows.Forms; 
  
namespace GFG { 
  
class PrintableForm:Form { 
  
    public static void Main() 
    { 
        Application.Run(new PrintableForm()); 
    } 
  
    public PrintableForm() 
    { 
        ResizeRedraw = true; 
    } 
  
    protected override void OnPaint(PaintEventArgs pea) 
    { 
        // Define Pen 
        Pen pen = new Pen(ForeColor); 
  
        // loop for all 7 horizontal lines to draw 
        for (int i = 0; i < 7; i++)  
        { 
            // Taking Block size to be 30x30 
            // So width and height will be 30*8=240 
            pea.Graphics.DrawLine(pen, i * 30, 0, i * 30, 240); 
        } 
  
        // loop for all 7 horizontal lines to draw 
        for (int i = 0; i < 7; i++)  
        { 
            pea.Graphics.DrawLine(pen, 0, i * 30, 
                                    240, i * 30); 
        } 
    } 
} 
}

輸出：

相關用法

注：本文由純淨天空篩選整理自ShivamChauhan5大神的英文原創作品 C# | Graphics.DrawLine() Method | Set – 1。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。