介绍 package com.example.swt369.simpleclock;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewTreeObserver;
import android.widget.Toast;
import java.util.Calendar;/* *
,* Created by swt369 提醒2017/8/20。
,*/public class ClockView extends View {
,//时钟各个部件的长度
,private float mScaleLengthLong;
,private float mScaleLengthShort;
,private float mTickLengthHour;
,private float mTickLengthMinute;
,private float mTickLengthSecond;
,//视图的宽和高
,private float mWidth;
,private float mHeight;
,//时钟半径
,private float mRadius;
,//绘制各部件时用的油漆
,private Paint mPaintScaleLong;
,private Paint mPaintScaleShort;
,private Paint mPaintOutline;
,private Paint mPaintNum;
,private Paint mPaintTickHour;
,private Paint mPaintTickMinute;
,private Paint mPaintTickSecond;
,private ViewTreeObserver.OnPreDrawListener onPreDrawListener;
,public ClockView (final Context 上下文,@Nullable AttributeSet attrs), {
超级才能(上下文,attrs);
时间=onPreDrawListener 才能;new ViewTreeObserver.OnPreDrawListener (), {
,,//获取视图宽高并计算各个部件的长度
@Override。才能
,,public boolean onPreDraw (), {
,,,mWidth =, getMeasuredWidth ();
,,,mHeight =, getMeasuredHeight ();
,,,mRadius =, Math.min (mWidth mHeight),/, 2, *, 0.95 f;
,,,mScaleLengthLong =, mRadius *, 0.1 f;
,,,mScaleLengthShort =, mRadius *, 0.05 f;
,,,mTickLengthHour =, mRadius *, 0.3 f;
,,,mTickLengthMinute =, mRadius *, 0.45 f;
,,,mTickLengthSecond =, mRadius *, 0.6 f;
,,,return 真实;
,,}
,,};
getViewTreeObserver才能().addOnPreDrawListener (onPreDrawListener);//点才能击显示具体时间
OnClickListener setOnClickListener才能(new (), {
@Override。才能
,,public void onClick (View v), {
,,,Calendar Calendar =, Calendar.getInstance ();
,,,String time =, String.format(“当前时间:% 2 d: % 2 d: % 02 d",
,,,,,calendar.get (Calendar.HOUR_OF_DAY) calendar.get (Calendar.MINUTE) calendar.get (Calendar.SECOND));
,,,Toast.makeText(上下文、时间,Toast.LENGTH_SHORT),告诉();
,,}
,,});//才能初始化所有油漆对象
initializePaints才能();
,}
,@Override
,protected void onDraw (Canvas 画布),{
如果才能(mWidth ==, 0, | |, mHeight ==, 0) {
,才能回报;
,,}
如果才能(onPreDrawListener !=, null) {
,,getViewTreeObserver () .removeOnPreDrawListener (onPreDrawListener);
,,onPreDrawListener =,空;
,,}//才能绘制时钟
drawClock才能(画布);//才能一秒后重绘
postInvalidateDelayed才能(1000);
,}
,private void drawClock (Canvas 画布),{//才能保存原始状态
canvas.save才能();//将才能坐标系原点移到中心,并逆时针旋转90度,完成后x轴朝上。
canvas.translate才能(时间/mWidth 2、mHeight /, 2);
canvas.rotate才能(-90);//画才能外围轮廓
canvas.drawCircle才能(0,0 mRadius, mPaintOutline);//画才能刻度
,,(int 小姐:=,0,,,小姐:& lt;, 12,,,我+ +){
,,String num =, String.valueOf(小姐:==,0,?,12,:,i);
,,如果小姐:%,3,==,0){
,,,canvas.drawLine (mRadius 0 mRadius 作用;mScaleLengthLong, 0,, mPaintScaleLong);
,,}else {
,,,canvas.drawLine (mRadius 0 mRadius 作用;mScaleLengthShort, 0,, mPaintScaleShort);
,,}
,,canvas.drawText (num mRadius 作用;mScaleLengthLong 作用;mPaintNum.measureText (num), *, 2 0,, mPaintNum);
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这篇文章给大家分享的是有关Android怎么实现简单时钟观点的方法的内容。小编觉得挺实用的,因此分享给大家做个参考,一起跟随小编过来看看吧。
通过画布的平移与旋转简化绘图逻辑是一个非常有用的技巧,下面的时钟观点就是利用这个方法完成的,省去了使用三角函数计算坐标的麻烦。
