C#五角星的集中畫法

2023年12月9日發(作者：陽字怎么寫)

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正多邊型的點坐標計算思想：

2010.4.9 整理

///五角形的內外園，圓心（a,a）

//float a = 100;

//float r1 = 100;

//float r2 = 40;

//for (int i = 0; i < 5; i++)

//{

// p1[i].X = a + (float)(i * 2 * / 5 - / 10)

* r1;

// p1[i].Y = a + (float)(i * 2 * / 5 - / 10)

* r1;

//}

//for (int i = 0; i < 5; i++)

//{

// p2[i].X = a + (float)(i * 2 * / 5 + 2 *

/ (2 * 5) - / 10) * r2;

// p2[i].Y = a + (float)(i * 2 * / 5 + 2 *

/ (2 * 5) - / 10) * r2;

//}

//for (int i = 0; i < 10; i++)

//{

// if (i % 2 == 0)

// {

// p[i] = p1[i / 2];

// }

// if (i % 2 == 1)

// {

// p[i] = p2[(int)(i / 2)];

// }

//}

畫法1（Button1的paint事件）：

GraphicsPath myGraphicsPath = new GraphicsPath();

PointF[] p1 = new [5];

[] p2 = new [5];

[] p = new [10];

////五角形的外接園，圓心（a,a）

float a = 100;

float r1 = 100;

float r2 = 40;

for (int i = 0; i < 5; i++)

{

p1[i].X = a + (float)(i * 2 * / 5 - / 10)

* r1;

p1[i].Y = a + (float)(i * 2 * / 5 - / 10)

* r1;

}

for (int i = 0; i < 5; i++)

{

p2[i].X = a + (float)(i * 2 * / 5 + 2 * /

(2 * 5) - / 10) * r2;

p2[i].Y = a + (float)(i * 2 * / 5 + 2 * /

(2 * 5) - / 10) * r2;

}

for (int i = 0; i < 10; i++)

{

if (i % 2 == 0)

{

p[i] = p1[i / 2];

}

if (i % 2 == 1)

{

p[i] = p2[(int)(i / 2)];

}

}

ygon(p);

lor = ;

= new (200, 200);

= new Region(myGraphicsPath);

畫法2：（paint 事件）

GraphicsPath myGraphicsPath = new GraphicsPath();

PointF[] p1 = new [5];

[] p2 = new [5];

float a = 100;

float r1 = 100;

float r2 = 40;

for (int i = 0; i < 5; i++) {

p1[i].X = a + (float)(i * 2 * / 5 - / 10)

* r1;

p1[i].Y = a + (float)(i * 2 * / 5 - / 10)

* r1;

}

for (int i = 0; i < 5; i++)

{

p2[i].X = a + (float)(i * 2 * / 5 + 2 * /

(2 * 5) - / 10) * r2;

p2[i].Y = a + (float)(i * 2 * / 5 + 2 * /

(2 * 5) - / 10) * r2;

}

for (int i = 0; i < 5; i++)

{

for (int j = i; j < i +1; j++)

e(p1[i],p2[j%5]);

}

lor = ;

= new (200, 200);

= new Region(myGraphicsPath);

畫法3（非事件畫法：通過顏色刷刷出來的。需要外部事件的觸發）

Brush fillBrush;

fillBrush = new SolidBrush();

Graphics g;

float a = 100;

float r1 = 100;

float r2 = 40;

PointF[] p1 = new [5];//float型point

[] p2 = new [5];

[] p = new [10];

for (int i = 0; i < 5; i++)

{

p1[i].X = a + (float)(i * 2 * / 5 - / 10)

* r1;

p1[i].Y = a + (float)(i * 2 * / 5 - / 10)

* r1;

} //Pen p = new Pen(, 2);

for (int i = 0; i < 5; i++)

{

p2[i].X = a + (float)(i * 2 * / 5 + 2 * /

(2 * 5) - / 10) * r2;

p2[i].Y = a + (float)(i * 2 * / 5 + 2 * /

(2 * 5) - / 10) * r2;

}

for (int i = 0; i < 10; i++)

{

if (i % 2 == 0)

{

p[i] = p1[i / 2];

}

if (i % 2 == 1)

{

p[i] = p2[(int)(i / 2)];

}

}

g = Graphics();

lygon(fillBrush, p);

畫法4（非事件畫法：連線。需要別的事件觸發）

Graphics g;

float a = 100;

float r1 = 100;

PointF[] p1 = new [5];

for (int i = 0; i < 5; i++)

{

p1[i].X = a + (float)(i * 2 * / 5 - / 10)

* r1;

p1[i].Y = a + (float)(i * 2 * / 5 - / 10)

* r1;

}

Pen p = new Pen( , 2);

g = Graphics();

ne(p, p1[0], p1[2]);

ne(p, p1[0], p1[3]); ne(p, p1[1], p1[3]);

ne(p, p1[1], p1[4]);

ne(p, p1[2], p1[4]);

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