图片可以拖到任意位置

01

public

class

DraftTest

extends

Activity
{

02

/**
Calledwhentheactivityisfirstcreated.*/

03

@Override

04

public

void

onCreate(Bundle
savedInstanceState){

05

super

.onCreate(savedInstanceState);

06

setContentView(R.layout.sign);

07

DisplayMetrics
dm=getResources().getDisplayMetrics();

08

final

int

screenWidth
=dm.widthPixels;

09

final

int

screenHeight
=dm.heightPixels-

50

;

10

//拖动的按钮

11

final

Button
b=(Button)findViewById(R.id.startBtn);

12

13

//添加触摸事件

14

15

b.setOnTouchListener(

new

OnTouchListener(){

16

int

lastX,
lastY;

//记录移动的最后的位置

17

public

boolean

onTouch(View
v,MotionEventevent){

18

//获取Action

19

20

int

ea=event.getAction();

21

22

Log.i(

"TAG"

,

"Touch:"

+ea);

23

switch

(ea){

24

case

MotionEvent.ACTION_DOWN:

//按下

25

lastX
=(

int

)
event.getRawX();

26

lastY
=(

int

)
event.getRawY();

27

break

;

28

/**

29

*
layout(l,t,r,b)

30

*
lLeftposition,relativetoparent

31

t
Topposition,relativetoparent

32

r
Rightposition,relativetoparent

33

b
Bottomposition,relativetoparent

34

*
*/

35

case

MotionEvent.ACTION_MOVE:

//移动

36

//移动中动态设置位置

37

int

dx
=(

int

)event.getRawX()
-lastX;

38

int

dy
=(

int

)event.getRawY()
-lastY;

39

int

left
=v.getLeft()+dx;

40

int

top
=v.getTop()+dy;

41

int

right
=v.getRight()+dx;

42

int

bottom
=v.getBottom()+dy;

43

if

(left
<

0

){

44

left
=

0

;

45

right
=left+v.getWidth();

46

}

47

if

(right
>screenWidth){

48

right
=screenWidth;

49

left
=right-v.getWidth();

50

}

51

if

(top
<

0

){

52

top
=

0

;

53

bottom
=top+v.getHeight();

54

}

55

if

(bottom
>screenHeight){

56

bottom
=screenHeight;

57

top
=bottom-v.getHeight();

58

}

59

v.layout(left,
top,right,bottom);

60

Log.i(

""

,

"position："

+
left+

",
"

+
top+

",
"

+
right+

",
"

+
bottom);

61

//将当前的位置再次设置

62

lastX
=(

int

)
event.getRawX();

63

lastY
=(

int

)
event.getRawY();

64

break

;

65

case

MotionEvent.ACTION_UP:

//脱离

66

break

;

67

}

68

return

false

;

69

}});

70

}

71

}

01

<?

xml

version

=

"1.0"

encoding

=

"utf-8"

?>

02

<

RelativeLayout

xmlns:android

=

"http://schemas.android.com/apk/res/android"

03

android:id

=

"@+id/layoutRacingNeedForSpeed"

android:padding

=

"0px"

04

android:layout_width

=

"fill_parent"

android:layout_height

=

"fill_parent"

>

05

<

Button

06

android:id

=

"@+id/startBtn"

07

android:text

=

"tuodongdeanniu"

08

android:layout_centerInParent

=

"true"

09

android:layout_width

=

"wrap_content"

android:layout_height

=

"wrap_content"

/>

10

</

RelativeLayout

>