Android编程基于自定义控件实现时钟功能的方法

package com.example.clock;
import java.util.Calendar;
import java.util.Date;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.util.AttributeSet;
import android.view.View;
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 

package com.example.clock;
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;
  }
}

package com.example.clock;
import android.app.Activity;
import android.os.Bundle;
public class ClockActivity extends Activity {
  /** Called when the activity is first created. */
  private ClockView clockView;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    clockView = (ClockView) findViewById(R.id.clock);
  }
  @Override
  protected void onResume() {
    super.onResume();
    clockView.startClock();
  }
  @Override
  protected void onStop() {
    super.onStop();
    clockView.stopClock();
  }
}

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