本文实例为大家分享了Android实现时钟效果的具体代码，供大家参考，具体内容如下

先看下最终的效果

开始实现

新建一个ClockView集成View

public class ClockView extends View {

}

先重写onMeasure方法，这里要先说一下View的测量模式，一共有三种：

1、EXACTLY

即精确值模式，当我们将控件的layout_width属性或layout_height属性指定为具体数值时，比如android:layout_width="100dp"，或者指定为math_parent属性时(占据父View的大小)，系统使用的是EXACTLY模式。

2、AT_MOST

即最大值模式，当控件的layout_width属性或layout_height属性指定为wrap_content时，控件大小一般随着控件的子控件或内容的变化而变化，此时控件的尺寸只要不超过父控件允许的最大尺寸即可。

3、UNSPECIFIED

这个属性比较奇怪——它不指定其大小测量模式，View想多大就多大，通常情况下在绘制自定义View时才会使用。

因为View的onMeasure方法只支持EXACTLY模式，当layout_width和layout_height为wrap_content时，View的大小就显得很奇怪了，如下图。

所以我们重写一下onMeasure方法可以指定View width、height的最小值

/**

* 当布局为wrap_content时设置默认长宽

* @param widthMeasureSpec

* @param heightMeasureSpec

*/

@Override

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

setMeasuredDimension(measure(widthMeasureSpec), measure(heightMeasureSpec));

}

private int measure(int origin){

int result = DEFAULT_MIN_WIDTH;

int specMode = MeasureSpec.getMode(origin);

int specSize = MeasureSpec.getSize(origin);

if(specMode == MeasureSpec.EXACTLY){

result = specSize;

}else{

if(specMode == MeasureSpec.AT_MOST){

result = Math.min(result, specSize);

}

}

return result;

}

下面就是最重要的重写onDraw方法来绘制表盘、刻度、指针……，大致流程如下

1、画表盘，用drawCircle绘制一个圆作为表盘, 圆心坐标为(getWidth()/2, getHeight()/2)，半径为Math.min(getHeight()/2, getWidth()/2)。

//画外圆

float borderWidth = DEFAULT_BORDER_WIDTH;

Paint paintCircle = new Paint();

paintCircle.setStyle(Paint.Style.STROKE);

paintCircle.setAntiAlias(true);

paintCircle.setStrokeWidth(borderWidth);

canvas.drawCircle(getWidth() / 2, getHeight() / 2, Math.min(getHeight() / 2, getWidth() / 2) - borderWidth / 2, paintCircle);

2、画刻度线，在这里我们可以利用一个`canvas.rotate'方法就可以不用计算角度了

//画刻度线

float degreeLength = 0f;

Paint paintDegree = new Paint();

paintDegree.setAntiAlias(true);

for(int i=0;i<60;i++){

if(i % 5 == 0){

paintDegree.setStrokeWidth(6);

degreeLength = DEFAULT_LONG_DEGREE_LENGTH;

}else{

paintDegree.setStrokeWidth(3);

degreeLength = DEFAULT_SHORT_DEGREE_LENGTH;

}

canvas.drawLine(getWidth()/2, Math.abs(getWidth()/2 - getHeight()/2), getWidth()/2, Math.abs(getWidth()/2 - getHeight()/2) + degreeLength, paintDegree);

canvas.rotate(360/60, getWidth()/2, getHeight()/2);

}

3、画刻度上的数字

//刻度数字

int degressNumberSize = 30;

canvas.translate(getWidth() / 2, getHeight() / 2);

Paint paintDegreeNumber = new Paint();

paintDegreeNumber.setTextAlign(Paint.Align.CENTER);

paintDegreeNumber.setTextSize(degressNumberSize);

paintDegreeNumber.setFakeBoldText(true);

for(int i=0;i<12;i++){

float[] temp = calculatePoint((i+1)*30, r - DEFAULT_LONG_DEGREE_LENGTH - degressNumberSize/2 - 15);

canvas.drawText((i+1)+"", temp[2], temp[3] + degressNumberSize/2-6, paintDegreeNumber);

}

/**

* 根据角度和长度计算线段的起点和终点的坐标

* @param angle

* @param length

* @return

*/

private float[] calculatePoint(float angle, float length){

float[] points = new float[4];

if(angle <= 90f){

points[0] = -(float) Math.sin(angle*Math.PI/180) * DEFAULT_POINT_BACK_LENGTH;

points[1] = (float) Math.cos(angle*Math.PI/180) * DEFAULT_POINT_BACK_LENGTH;

points[2] = (float) Math.sin(angle*Math.PI/180) * length;

points[3] = -(float) Math.cos(angle*Math.PI/180) * length;

}else if(angle <= 180f){

points[0] = -(float) Math.cos((angle-90)*Math.PI/180) * DEFAULT_POINT_BACK_LENGTH;

points[1] = -(float) Math.sin((angle-90)*Math.PI/180) * DEFAULT_POINT_BACK_LENGTH;

points[2] = (float) Math.cos((angle-90)*Math.PI/180) * length;

points[3] = (float) Math.sin((angle-90)*Math.PI/180) * length;

}else if(angle <= 270f){

points[0] = (float) Math.sin((angle-180)*Math.PI/180) * DEFAULT_POINT_BACK_LENGTH;

points[1] = -(float) Math.cos((angle-180)*Math.PI/180) * DEFAULT_POINT_BACK_LENGTH;

points[2] = -(float) Math.sin((angle-180)*Math.PI/180) * length;

points[3] = (float) Math.cos((angle-180)*Math.PI/180) * length;

}else if(angle <= 360f){

points[0] = (float) Math.cos((angle-270)*Math.PI/180) * DEFAULT_POINT_BACK_LENGTH;

points[1] = (float) Math.sin((angle-270)*Math.PI/180) * DEFAULT_POINT_BACK_LENGTH;

points[2] = -(float) Math.cos((angle-270)*Math.PI/180) * length;

points[3] = -(float) Math.sin((angle-270)*Math.PI/180) * length;

}

return points;

}

4、画指针

//画指针

Paint paintHour = new Paint();

paintHour.setAntiAlias(true);

paintHour.setStrokeWidth(15);

Paint paintMinute = new Paint();

paintMinute.setAntiAlias(true);

paintMinute.setStrokeWidth(10);

Paint paintSecond = new Paint();

paintSecond.setAntiAlias(true);

paintSecond.setStrokeWidth(5);

Calendar now = Calendar.getInstance();

float[] hourPoints = calculatePoint(now.get(Calendar.HOUR_OF_DAY)%12/12f*360, hourPointerLength);

canvas.drawLine(hourPoints[0], hourPoints[1], hourPoints[2], hourPoints[3], paintHour);

float[] minutePoints = calculatePoint(now.get(Calendar.MINUTE)/60f*360, minutePointerLength);

canvas.drawLine(minutePoints[0], minutePoints[1], minutePoints[2], minutePoints[3], paintMinute);

float[] secondPoints = calculatePoint(now.get(Calendar.SECOND)/60f*360, secondPointerLength);

canvas.drawLine(secondPoints[0], secondPoints[1], secondPoints[2], secondPoints[3], paintSecond);

5、画圆心

//画圆心

Paint paintCenter = new Paint();

paintCenter.setColor(Color.WHITE);

canvas.drawCircle(0, 0, 2, paintCenter);

最后只要启动一个无限循环的线程，每隔1秒针重绘一下View就能让指针动起来了

private Thread timeThread = new Thread() {

@Override

public void run() {

try {

while(true){

updateHandler.sendEmptyMessage(0);

Thread.sleep(1000);

}

} catch (InterruptedException e) {

e.printStackTrace();

}

}

};

private Handler updateHandler = new Handler() {

@Override

public void handleMessage(Message msg) {

invalidate();

}

};

以上就是教大家如何利用Android画个时钟的详细步骤代码，希望对大家的学习Android软件编程有所帮助。