【移動(dòng)應(yīng)用開(kāi)發(fā)技術(shù)】怎么在Android中通過(guò)自定義控件實(shí)現(xiàn)時(shí)鐘功能

【移動(dòng)應(yīng)用開(kāi)發(fā)技術(shù)】怎么在Android中通過(guò)自定義控件實(shí)現(xiàn)時(shí)鐘功能

這篇文章將為大家詳細(xì)講解有關(guān)怎么在Android中通過(guò)自定義控件實(shí)現(xiàn)時(shí)鐘功能，文章內(nèi)容質(zhì)量較高，因此在下分享給大家做個(gè)參考，希望大家閱讀完這篇文章后對(duì)相關(guān)知識(shí)有一定的了解。自定義控件的代碼（ClockView.java）：package

com.example.clock;

import

java.util.Calendar;

import

java.util.Date;

import

android.content.Context;

import

android.graphics.Canvas;

import

android.graphics.Color;

import

android.graphics.Paint;

import

android.os.Handler;

import

android.os.Looper;

import

android.os.Message;

import

android.util.AttributeSet;

import

android.view.View;

public

class

ClockView

extends

View

{

private

Paint

circlePaint,

dialPaint,

numberPaint;

//

view

的寬高

private

float

mWidth,

mHeight;

//

圓的半徑

private

float

circleRadius;

//

圓心X,Y坐標(biāo)

private

float

circleX,

circleY;

private

int

second,

minute;

private

double

hour;

private

Handler

handler

=

new

Handler(Looper.getMainLooper())

{

@Override

public

void

handleMessage(Message

msg)

{

super.handleMessage(msg);

if

(msg.what

==

0)

{

invalidate();

}

}

};

public

ClockView(Context

context,

AttributeSet

attrs)

{

super(context,

attrs);

initPaint();

}

private

void

initPaint()

{

//

刻盤圓，小時(shí)刻度，時(shí)針和分針的畫筆

circlePaint

=

new

Paint(Paint.ANTI_ALIAS_FLAG);

circlePaint.setColor(Color.BLACK);

circlePaint.setStyle(Paint.Style.STROKE);

circlePaint.setStrokeWidth(10);

//

分鐘刻度的畫筆

dialPaint

=

new

Paint(Paint.ANTI_ALIAS_FLAG);

dialPaint.setColor(Color.BLACK);

dialPaint.setStrokeWidth(5);

//

數(shù)字的畫筆

numberPaint

=

new

Paint(Paint.ANTI_ALIAS_FLAG);

numberPaint.setColor(Color.BLACK);

numberPaint.setStrokeWidth(5);

numberPaint.setTextSize(30);

}

@Override

protected

void

onMeasure(int

widthMeasureSpec,

int

heightMeasureSpec)

{

super.onMeasure(widthMeasureSpec,

heightMeasureSpec);

mWidth

=

getMeasuredWidth();

mHeight

=

getMeasuredHeight();

if

(mWidth

<

mHeight)

{

//

圓的半徑為view的寬度的一半再減9，防止貼邊

circleRadius

=

mWidth

/

2

-

9;

circleX

=

mWidth

/

2;

circleY

=

mHeight

/

2;

}

else

{

circleRadius

=

mHeight

/

2

-

9;

circleX

=

mWidth

/

2;

circleY

=

mHeight

/

2;

}

}

@Override

protected

void

onDraw(Canvas

canvas)

{

super.onDraw(canvas);

setTimes();

drawCirclePoint(canvas);

drawCircle(canvas);

drawDial(canvas);

drawPointer(canvas);

}

/**

*

圓心

*

*

@param

canvas

*/

private

void

drawCirclePoint(Canvas

canvas)

{

canvas.drawCircle(circleX,

circleY,

5,

circlePaint);

}

private

void

drawCircle(Canvas

canvas)

{

canvas.drawCircle(circleX,

circleY,

circleRadius,

circlePaint);

}

/**

*

畫刻度及時(shí)間

*

*

@param

canvas

*/

private

void

drawDial(Canvas

canvas)

{

//

時(shí)鐘用長(zhǎng)一點(diǎn)的刻度，畫筆用畫圓的畫筆

Point

hourStartPoint

=

new

Point(circleX,

circleY

-

circleRadius);

Point

hourEndPoint

=

new

Point(circleX,

circleY

-

circleRadius

+

40);

//

分鐘的刻度要稍微短一些，畫筆用畫圓的畫筆

Point

startPoint2

=

new

Point(circleX,

circleY

-

circleRadius);

Point

endPoint2

=

new

Point(circleX,

circleY

-

circleRadius

+

10);

//

開(kāi)始畫刻度和數(shù)字，總共60個(gè)刻度，12個(gè)時(shí)鐘刻度，被5整除畫一個(gè)時(shí)鐘刻度，被其余的為分針刻度

String

clockNumber;

for

(int

i

=

0;

i

<

60;

i++)

{

if

(i

%

5

==

0)

{

if

(i

==

0)

{

clockNumber

=

"12";

}

else

{

clockNumber

=

String.valueOf(i

/

5);

}

//

時(shí)針刻度

canvas.drawLine(hourStartPoint.getX(),

hourStartPoint.getY(),

hourEndPoint.getX(),

hourEndPoint.getY(),

circlePaint);

//

畫數(shù)字，需在時(shí)針刻度末端加30

canvas.drawText(clockNumber,

circleX

-

numberPaint.measureText(clockNumber)

/

2,

hourEndPoint.getY()

+

30,

numberPaint);

}

else

{

//

畫分針刻度

canvas.drawLine(startPoint2.getX(),

startPoint2.getY(),

endPoint2.getX(),

endPoint2.getY(),

circlePaint);

}

//

畫布旋轉(zhuǎn)6度

canvas.rotate(360

/

60,

circleX,

circleY);

}

}

/**

*

畫指針

X點(diǎn)坐標(biāo)

cos(弧度)*r

Y點(diǎn)坐標(biāo)

sin(弧度)*r

toRadians將角度轉(zhuǎn)成弧度

*

安卓坐標(biāo)系與數(shù)學(xué)坐標(biāo)系不同的地方是X軸是相反的，所以為了調(diào)整方向，需要將角度+270度

*

*

@param

canvas

*/

private

void

drawPointer(Canvas

canvas)

{

canvas.translate(circleX,

circleY);

float

hourX

=

(float)

Math.cos(Math.toRadians(hour

*

30

+

270))

*

circleRadius

*

0.5f;

float

hourY

=

(float)

Math.sin(Math.toRadians(hour

*

30

+

270))

*

circleRadius

*

0.5f;

float

minuteX

=

(float)

Math.cos(Math.toRadians(minute

*

6

+

270))

*

circleRadius

*

0.8f;

float

minuteY

=

(float)

Math.sin(Math.toRadians(minute

*

6

+

270))

*

circleRadius

*

0.8f;

float

secondX

=

(float)

Math.cos(Math.toRadians(second

*

6

+

270))

*

circleRadius

*

0.8f;

float

secondY

=

(float)

Math.sin(Math.toRadians(second

*

6

+

270))

*

circleRadius

*

0.8f;

canvas.drawLine(0,

0,

hourX,

hourY,

circlePaint);

canvas.drawLine(0,

0,

minuteX,

minuteY,

circlePaint);

canvas.drawLine(0,

0,

secondX,

secondY,

dialPaint);

//

一秒重繪一次

handler.sendEmptyMessageDelayed(0,

1000);

}

public

void

startClock()

{

setTimes();

invalidate();

}

private

void

setTimes()

{

Date

date

=

new

Date();

Calendar

calendar

=

Calendar.getInstance();

calendar.setTime(date);

second

=

getTimes(date,

Calendar.SECOND);

minute

=

getTimes(date,

Calendar.MINUTE);

hour

=

getTimes(date,

Calendar.HOUR)

+

minute

/

12

*

0.2;

}

private

int

getTimes(Date

date,

int

calendarField)

{

Calendar

calendar

=

Calendar.getInstance();

calendar.setTime(date);

return

calendar.get(calendarField);

}

public

void

stopClock()

{

handler.removeMessages(0);

}

}Point.java：package

com.example.clock;

public

class

Point

{

private

float

x;

private

float

y;

public

Point(float

x,

float

y)

{

this.x

=

x;

this.y

=

y;

}

public

float

getX()

{

return

x;

}

public

void

setX(float

x)

{

this.x

=

x;

}

public

float

getY()

{

return

y;

}

public

void

setY(float

y)

{

this.y

=

y;

}

}Acitivity（ClockActivity.java）：package

com.example.clock;

import

android.app.Activity;

import

android.os.Bundle;

public

class

ClockActivity

extends

Activity

{

/**

Called

when

the

activity

is

first

created.

*/

private

ClockView

clockView;

@Override

protected

void

onCreate(Bundle

savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

clockView

=

(ClockView)

findViewById(R.id.clock);

}

@Override

protected

void

onResume()

{

super.on