【移动应用开发技术】Android开发中如何理解RadioButton及路径绘制

【移动应用开发技术】Android开发中如何理解RadioButton及路径绘制

这篇文章将为大家详细讲解有关Android开发中如何理解RadioButton及路径绘制，文章内容质量较高，因此在下分享给大家做个参考，希望大家阅读完这篇文章后对相关知识有一定的了解。这个例子是绘制多边形，多义形和路径，采用单选钮RadioButton来选择Polys和Path示例:UI设计为上部分用来显示绘图内容，下部分为两个单选按钮Polys，Path。这样layout就和main.xml

不一样，main.xml只含一个com.pstreets.graphics2d.GuidebeeGraphics2DView。因此需在res\layout下新建一个polys.xml：<?xml

version=”1.0″

encoding=”utf-8″?>

<LinearLayout

xmlns:android=”/apk/res/android”

android:orientation=”vertical”

android:background=”@drawable/white”

android:layout_width=”fill_parent”

android:layout_height=”fill_parent”>

<com.pstreets.graphics2d.GuidebeeGraphics2DView

android:id=”@+id/graphics2dview”

android:layout_weight=”1″

android:layout_width=”fill_parent”

android:layout_height=”wrap_content”/>

<LinearLayout

xmlns:android=”/apk/res/android”

android:layout_width=”wrap_content”

android:layout_height=”wrap_content”

android:orientation=”horizontal”

>

<RadioGroup

android:layout_width=”wrap_content”

android:orientation=”horizontal”

android:textSize=”20dp”

android:layout_height=”wrap_content”>

<RadioButton

android:text=”Polys”

android:id=”@+id/radioPolys”

android:layout_width=”wrap_content”

android:textColor=”@color/black”

android:checked=”true”

android:layout_height=”wrap_content”>

</RadioButton>

<RadioButton

android:text=”Path”

android:id=”@+id/radioPath”

android:layout_width=”wrap_content”

android:textColor=”@color/black”

android:layout_height=”wrap_content”>

</RadioButton>

</RadioGroup>

</LinearLayout>

</LinearLayout>RadioButton需包含在RadioGroup中做为一个分组，这里将Polys设为选中。定义好Layout资源后，修改Path.javaprivate

RadioButton

radioPoly;

private

RadioButton

radioPath;

public

void

onCreate(Bundle

savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.polys);

graphic2dView

=

(GuidebeeGraphics2DView)

findViewById(R.id.graphics2dview);

radioPath

=

(RadioButton)

findViewById(R.id.radioPath);

radioPoly

=

(RadioButton)

findViewById(R.id.radioPolys);

radioPath.setOnClickListener(this);

radioPoly.setOnClickListener(this);

}应为需要处理按键消息，所以定义了两个RadioButton对象，可以通过findViewById获取实例。因为两个RadioButton这里采用同样的处理方法，可以让Path实现OnClickListener，即：publicclassPathextends

Graphics2DActivity

implementsOnClickListener。完整代码如下：1

public

class

Path

extends

Graphics2DActivity

2

implements

OnClickListener

{

3

4

private

RadioButton

radioPoly;

5

private

RadioButton

radioPath;

6

7

public

void

onCreate(Bundle

savedInstanceState)

{

8

super.onCreate(savedInstanceState);

9

setContentView(R.layout.polys);

10

graphic2dView

11

=

(GuidebeeGraphics2DView)

12

findViewById(R.id.graphics2dview);

13

radioPath

=

(RadioButton)

findViewById(R.id.radioPath);

14

radioPoly

=

(RadioButton)

findViewById(R.id.radioPolys);

15

radioPath.setOnClickListener(this);

16

radioPoly.setOnClickListener(this);

17

}

18

19

@Override

20

protected

void

drawImage()

{

21

if

(radioPoly.isChecked())

{

22

drawPolys();

23

}

else

{

24

drawPaths();

25

}

26

graphic2dView.refreshCanvas();

27

28

}

29

30

@Override

31

public

void

onClick(View

view)

{

32

drawImage();

33

}

34

35

private

void

drawPaths()

{

36

AffineTransform

mat1;

37

38

//

The

path.

39

com.mapdigit.drawing.geometry.Path

path;

40

41

//

Colors

42

Color

redColor

=

new

Color(0x96ff0000,

true);

43

Color

greenColor

=

new

Color(0xff00ff00);

44

Color

blueColor

=

new

Color(0x750000ff,

true);

45

46

String

pathdata

47

=

"M

60

20

Q

-40

70

60

120

Q

160

70

60

20

z";

48

mat1

=

new

AffineTransform();

49

mat1.translate(30,

40);

50

mat1.rotate(-30

*

Math.PI

/

180.0);

51

path

=

com.mapdigit.drawing.geometry.Path.fromString(pathdata);

52

//

Clear

the

canvas

with

white

color.

53

graphics2D.clear(Color.WHITE);

54

55

graphics2D.setAffineTransform(new

AffineTransform());

56

SolidBrush

brush

=

new

SolidBrush(greenColor);

57

graphics2D.fill(brush,

path);

58

graphics2D.setAffineTransform(mat1);

59

60

brush

=

new

SolidBrush(blueColor);

61

com.mapdigit.drawing.Pen

pen

62

=

new

com.mapdigit.drawing.Pen(redColor,

5);

63

graphics2D.setPenAndBrush(pen,

brush);

64

graphics2D.draw(null,

path);

65

graphics2D.fill(null,

path);

66

67

}

68

69

private

void

drawPolys()

{

70

AffineTransform

mat1;

71

72

//

Colors

73

Color

redColor

=

new

Color(0x96ff0000,

true);

74

Color

greenColor

=

new

Color(0xff00ff00);

75

Color

blueColor

=

new

Color(0x750000ff,

true);

76

77

Polyline

polyline;

78

Polygon

polygon;

79

Polygon

polygon1;

80

81

String

pointsdata1

82

=

"59,45,95,63,108,105,82,139,39,140,11,107,19,65";

83

mat1

=

new

AffineTransform();

84

mat1.translate(30,

40);

85

mat1.rotate(-30

*

Math.PI

/

180.0);

86

polyline

=

new

Polyline();

87

polygon

=

new

Polygon();

88

polygon1

=

new

Polygon();

89

Point[]

points

=

Point.fromString(pointsdata1);

90

for

(int

i

=

0;

i

<

points.length;

i++)

{

91

polyline.addPoint(points[i].x,

points[i].y);

92

polygon.addPoint(points[i].x,

points[i].y);

93

polygon1.addPoint(points[i].x,

points[i].y);

94

}

95

//

Clear

the

canvas

with

white

color.

96

graphics2D.clear(Color.WHITE);

97

98