Android中怎么通过自定义控件实现时钟效果

本篇文章给大家分享的是有关Android中怎么通过自定义控件实现时钟效果，小编觉得挺实用的，因此分享给大家学习，希望大家阅读完这篇文章后可以有所收获，话不多说，跟着小编一起来看看吧。

代码实现

自定义控件的代码：

public class ClockView extends View{ private Paint circlePaint,dialPaint,numberPaint; //view 的宽高 private float mWidth,mHeight; //圆的半径 private float circleRadius; //圆心X,Y坐标 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(){  //刻盘圆，小时刻度，时针和分针的画笔  circlePaint = new Paint(Paint.ANTI_ALIAS_FLAG);  circlePaint.setColor(Color.BLACK);  circlePaint.setStyle(Paint.Style.STROKE);  circlePaint.setStrokeWidth(10);  //分钟刻度的画笔  dialPaint = new Paint(Paint.ANTI_ALIAS_FLAG);  dialPaint.setColor(Color.BLACK);  dialPaint.setStrokeWidth(5);  //数字的画笔  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){   //圆的半径为view的宽度的一半再减9，防止贴边   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); } /**圆心  * @param canvas  */ private void drawCirclePoint(Canvas canvas){  canvas.drawCircle(circleX,circleY,5,circlePaint); } private void drawCircle(Canvas canvas){  canvas.drawCircle(circleX,circleY,circleRadius,circlePaint); } /**画刻度及时间  * @param canvas  */ private void drawDial(Canvas canvas){  //时钟用长一点的刻度，画笔用画圆的画笔  Point hourStartPoint = new Point(circleX,circleY-circleRadius);  Point hourEndPoint = new Point(circleX,circleY-circleRadius+40);  //分钟的刻度要稍微短一些，画笔用画圆的画笔  Point startPoint2 = new Point(circleX,circleY-circleRadius);  Point endPoint2 = new Point(circleX,circleY-circleRadius+10);  //开始画刻度和数字，总共60个刻度，12个时钟刻度，被5整除画一个时钟刻度，被其余的为分针刻度  String clockNumber;  for(int i=0;i<60;i++){   if(i%5==0){    if(i==0){     clockNumber = "12";    } else{     clockNumber = String.valueOf(i/5);    }    //时针刻度    canvas.drawLine(hourStartPoint.getX(),hourStartPoint.getY(),hourEndPoint.getX(),hourEndPoint.getY(),circlePaint);    //画数字，需在时针刻度末端加30    canvas.drawText(clockNumber,circleX-numberPaint.measureText(clockNumber)/2,hourEndPoint.getY()+30,numberPaint);   } else{    //画分针刻度    canvas.drawLine(startPoint2.getX(),startPoint2.getY(),endPoint2.getX(),endPoint2.getY(),circlePaint);   }   //画布旋转6度   canvas.rotate(360/60,circleX,circleY);  } } /**画指针  * X点坐标 cos(弧度)*r  * Y点坐标 sin(弧度)*r  * toRadians将角度转成弧度  * 安卓坐标系与数学坐标系不同的地方是X轴是相反的，所以为了调整方向，需要将角度+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);  //一秒重绘一次  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); }}

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：

public class ClockActivity extends Activity{  private ClockView clockView;  @Override  protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.clock_layout);   clockView = (ClockView) findViewById(R.id.clock);  }  @Override  protected void onResume() {   super.onResume();   clockView.startClock();  }  @Override  protected void onStop() {   super.onStop();   clockView.stopClock();  } }

xml布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:gravity="center" android:layout_height="match_parent"> <com.example.customview.view.ClockView  android:layout_width="match_parent"  android:id="@+id/clock"  android:layout_height="match_parent" /></LinearLayout>

以上就是Android中怎么通过自定义控件实现时钟效果，小编相信有部分知识点可能是我们日常工作会见到或用到的。希望你能通过这篇文章学到更多知识。更多详情敬请关注亿速云行业资讯频道。