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

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