android自定义简单时钟

本文实例为大家分享了android实现简单时钟的具体代码，供大家参考，具体内容如下

attrs定义如下

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="ClockView">
 <attr name="pointer_color" format="color" />
 <attr name="scale_color" format="color" />
 <attr name="one_circle_color" format="color" />
 <attr name="two_circle_color" format="color" />
 <attr name="three_circle_color" format="color" />
 <attr name="four_circle_color" format="color" />
</declare-styleable>
</resources>

自定义ClockView代码如下

package com.example.helloworld;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;

import androidx.annotation.Nullable;

import java.util.Calendar;

/**
* 时钟
*
* @since 2021-02-29
* @author Sar
*/
public class ClockView extends View {
private static final int DEFAULT_POINTER_COLOR = Color.parseColor("#FFFFFF");
private static final int DEFAULT_SCALE_COLOR = Color.parseColor("#FFFFFF");
private static final int DEFAULT_ONE_CIRCLE_COLOR = Color.parseColor("#FFFFFF");
private static final int DEFAULT_TWO_CIRCLE_COLOR = Color.parseColor("#CCCCCC");
private static final int DEFAULT_THREE_CIRCLE_COLOR = Color.parseColor("#BBBBBB");
private static final int DEFAULT_FOUR_CIRCLE_COLOR = Color.parseColor("#AAAAAA");
private static final int DEFAULT_FOUR_CIRCLE_DIAMETER = 180; // 默认外圈圆直径，也就是该控件默认宽高，单位dp

private int pointerColor; // 指针颜色
private int scaleColor; // 刻度颜色
private int oneCircleColor; // 中心圆颜色
private int twoCircleColor; // 次中心圆颜色
private int threeCircleColor; // 次外圈圆颜色
private int fourCircleColor; // 外圈圆颜色

private Paint paint;

private int cx;
private int cy;
private int scaleStrokeWidth;
private int hourPointerWidth;
private int minutePointerWidth;
private int oneCircleDiameter;
private int twoCircleDiameter;
private int threeCircleDiameter;
private int fourCircleDiameter;
private int defaultFourCircleDiameter;

public ClockView(Context context) {
 super(context);
 init(context, null, 0);
}

public ClockView(Context context, @Nullable AttributeSet attrs) {
 super(context, attrs);
 init(context, attrs, 0);
}

public ClockView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);
 init(context, attrs, defStyleAttr);
}

private void init(Context context, AttributeSet attrs, int defStyleAttr) {
 if (attrs != null) {
  TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.ClockView, defStyleAttr, 0);
  pointerColor = typedArray.getColor(R.styleable.XTClockView_pointer_color, DEFAULT_POINTER_COLOR);
  scaleColor = typedArray.getColor(R.styleable.XTClockView_scale_color, DEFAULT_SCALE_COLOR);
  oneCircleColor = typedArray.getColor(R.styleable.XTClockView_one_circle_color, DEFAULT_ONE_CIRCLE_COLOR);
  twoCircleColor = typedArray.getColor(R.styleable.XTClockView_two_circle_color, DEFAULT_TWO_CIRCLE_COLOR);
  threeCircleColor = typedArray.getColor(R.styleable.XTClockView_three_circle_color, DEFAULT_THREE_CIRCLE_COLOR);
  fourCircleColor = typedArray.getColor(R.styleable.XTClockView_four_circle_color, DEFAULT_FOUR_CIRCLE_COLOR);
  typedArray.recycle();
 } else {
  pointerColor = DEFAULT_POINTER_COLOR;
  scaleColor = DEFAULT_SCALE_COLOR;
  oneCircleColor = DEFAULT_ONE_CIRCLE_COLOR;
  twoCircleColor = DEFAULT_TWO_CIRCLE_COLOR;
  threeCircleColor = DEFAULT_THREE_CIRCLE_COLOR;
  fourCircleColor = DEFAULT_FOUR_CIRCLE_COLOR;
 }
 paint = new Paint(Paint.ANTI_ALIAS_FLAG);
 paint.setStyle(Paint.Style.FILL);
 defaultFourCircleDiameter = dp2px(context, DEFAULT_FOUR_CIRCLE_DIAMETER);
}

public void setPointerColor(int pointerColor) {
 this.pointerColor = pointerColor;
}

public void setScaleColor(int scaleColor) {
 this.scaleColor = scaleColor;
}

public void setOneCircleColor(int oneCircleColor) {
 this.oneCircleColor = oneCircleColor;
}

public void setTwoCircleColor(int twoCircleColor) {
 this.twoCircleColor = twoCircleColor;
}

public void setThreeCircleColor(int threeCircleColor) {
 this.threeCircleColor = threeCircleColor;
}

public void setFourCircleColor(int fourCircleColor) {
 this.fourCircleColor = fourCircleColor;
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 super.onMeasure(widthMeasureSpec, heightMeasureSpec);
 int width = 0;
 int height = 0;
 int widthMode = MeasureSpec.getMode(widthMeasureSpec);
 int widthSize = MeasureSpec.getSize(widthMeasureSpec);
 switch (widthMode) {
  case MeasureSpec.EXACTLY:
   width = widthSize;
   break;
  case MeasureSpec.AT_MOST:
  case MeasureSpec.UNSPECIFIED:
   width = defaultFourCircleDiameter;
   break;
 }
 int heightMode = MeasureSpec.getMode(heightMeasureSpec);
 int heightSize = MeasureSpec.getSize(heightMeasureSpec);
 switch (heightMode) {
  case MeasureSpec.EXACTLY:
   height = heightSize;
   break;
  case MeasureSpec.AT_MOST:
  case MeasureSpec.UNSPECIFIED:
   height = defaultFourCircleDiameter;
   break;
 }
 setMeasuredDimension(width, height);
 cx = width / 2;
 cy = height / 2;
 fourCircleDiameter = Math.min(width, height);
 threeCircleDiameter = fourCircleDiameter * 7 / 10;
 twoCircleDiameter = fourCircleDiameter * 28 / 50;
 oneCircleDiameter = fourCircleDiameter * 3 / 50;
 scaleStrokeWidth = fourCircleDiameter / 100;
 hourPointerWidth = oneCircleDiameter * 2 / 5;
 minutePointerWidth = oneCircleDiameter / 5;
}

private int dp2px(Context context, int dpValue) {
 float scale = context.getResources().getDisplayMetrics().density;
 return (int) (dpValue * scale + 0.5f);
}

@Override
protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 drawCircle(canvas, fourCircleColor, fourCircleDiameter);
 drawCircle(canvas, threeCircleColor, threeCircleDiameter);
 drawCircle(canvas, twoCircleColor, twoCircleDiameter);

drawScale(canvas);
 Calendar calendar = Calendar.getInstance();
 calendar.setTimeInMillis(System.currentTimeMillis());
 int hour = calendar.get(Calendar.HOUR);
 int minute = calendar.get(Calendar.MINUTE);
 int second = calendar.get(Calendar.SECOND);

paint.setColor(pointerColor);
 drawPointer(canvas, (float) (hour * 30 + minute * 0.5), hourPointerWidth, cy - twoCircleDiameter / 2 * 2 / 3);
 drawPointer(canvas, minute * 6, minutePointerWidth, cy - twoCircleDiameter / 2 * 4 / 5);
 drawPointer(canvas, second * 6, minutePointerWidth, cy - twoCircleDiameter / 2 * 8 / 9);

paint.setStrokeWidth(0);
 drawCircle(canvas, oneCircleColor, oneCircleDiameter);

postInvalidateDelayed(1000);
}

private void drawCircle(Canvas canvas, int circleColor, int circleDiameter) {
 paint.setColor(circleColor);
 canvas.drawCircle(cx, cy, circleDiameter / 2, paint);
}

private void drawScale(Canvas canvas) {
 paint.setColor(scaleColor);
 paint.setStrokeWidth(scaleStrokeWidth);
 for (int i = 0; i < 12; i++) {
  canvas.save();
  canvas.rotate(i * 30, cx, cy);
  canvas.drawLine(cx, (fourCircleDiameter - threeCircleDiameter) / 6, cx, (fourCircleDiameter - threeCircleDiameter) / 3, paint);
  canvas.restore();
 }
}

private void drawPointer(Canvas canvas, float rotateDegrees, float strokeWidth, float stopY) {
 paint.setStrokeWidth(strokeWidth);
 canvas.save();
 canvas.rotate(rotateDegrees, cx, cy);
 canvas.drawLine(cx, cy, cx, stopY, paint);
 canvas.restore();
}
}

效果图如下

来源：https://blog.csdn.net/sar1618/article/details/114220933