Android 自定义view的简单应用（3） 时钟

先上效果图：

布局文件：

自定义View 文件：

public class Clock extends View {
    int width = 800;
    int height = 800;

    public Clock(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        setMeasuredDimension(width,height);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        canvas.drawColor(Color.TRANSPARENT);

        /*
        绘制原盘
         */
        Paint CircleBgPaint = new Paint();
        CircleBgPaint.setColor(Color.WHITE);
        CircleBgPaint.setStyle(Paint.Style.FILL);
        CircleBgPaint.setAntiAlias(true);

        int Radius = width / 2 - 60;
        canvas.drawCircle(width /2 ,height / 2,Radius,CircleBgPaint);

        /*
        绘制原盘边框
         */
        Paint CircleBgStrkoePaint = new Paint();
        CircleBgStrkoePaint.setColor(Color.BLACK);
        CircleBgStrkoePaint.setStrokeWidth(20);
        CircleBgStrkoePaint.setStyle(Paint.Style.STROKE);
        CircleBgStrkoePaint.setAntiAlias(true);

        canvas.drawCircle(width /2 ,height / 2,Radius,CircleBgStrkoePaint);

        /*
        绘制刻度
        分2个数组 因为drawLines 的大小限制
         */
        Paint MarkPaint = new Paint();
        MarkPaint.setColor(Color.BLACK);
        MarkPaint.setStyle(Paint.Style.FILL);
        MarkPaint.setAntiAlias(true);
        MarkPaint.setStrokeWidth(20);

        int R1 = Radius - 35;

        int CenterX = width / 2;
        int CenterY = height / 2;

        float[] Marks = new float[7 * 4];
        float[] Marks2 = new float[5 * 4];

        for(int i = 0; i < 12;i++)
        {
            if(i <= 3) {
                int degree = i * 30;

                int x_s = (int) (Math.sin(Math.toRadians(degree)) * R1);
                int y_s = (int) (Math.cos(Math.toRadians(degree)) * R1);

                int x_e = (int) (Math.sin(Math.toRadians(degree)) * Radius);
                int y_e = (int) (Math.cos(Math.toRadians(degree)) * Radius);

                Marks[i * 4] = CenterX + x_s;
                Marks[i * 4 + 1] = CenterY - y_s;
                Marks[i * 4 + 2] = CenterX + x_e;
                Marks[i * 4 + 3] = CenterY - y_e;
            }
            else if(i <= 6)
            {
                int degree = (i - 3) * 30;

                int y_s = (int) (Math.sin(Math.toRadians(degree)) * R1);
                int x_s = (int) (Math.cos(Math.toRadians(degree)) * R1);

                int y_e = (int) (Math.sin(Math.toRadians(degree)) * Radius);
                int x_e = (int) (Math.cos(Math.toRadians(degree)) * Radius);

                Marks[i * 4] = CenterX + x_s;
                Marks[i * 4 + 1] = CenterY + y_s;
                Marks[i * 4 + 2] = CenterX + x_e;
                Marks[i * 4 + 3] = CenterY + y_e;
            }
            else if(i <= 9)
            {
                int degree = (i - 6) * 30;

                int x_s = (int) (Math.sin(Math.toRadians(degree)) * R1);
                int y_s = (int) (Math.cos(Math.toRadians(degree)) * R1);

                int x_e = (int) (Math.sin(Math.toRadians(degree)) * Radius);
                int y_e = (int) (Math.cos(Math.toRadians(degree)) * Radius);

                Marks2[( i - 7 ) * 4] = CenterX - x_s;
                Marks2[( i - 7 ) * 4 + 1] = CenterY + y_s;
                Marks2[( i - 7 ) * 4 + 2] = CenterX - x_e;
                Marks2[( i - 7 ) * 4 + 3] = CenterY + y_e;
            }
            else if(i <= 11)
            {
                int degree = (i - 9) * 30;

                int y_s = (int) (Math.sin(Math.toRadians(degree)) * R1);
                int x_s = (int) (Math.cos(Math.toRadians(degree)) * R1);

                int y_e = (int) (Math.sin(Math.toRadians(degree)) * Radius);
                int x_e = (int) (Math.cos(Math.toRadians(degree)) * Radius);

                Marks2[( i - 7 ) * 4] = CenterX - x_s;
                Marks2[( i - 7 ) * 4 + 1] = CenterY - y_s;
                Marks2[( i - 7 ) * 4 + 2] = CenterX - x_e;
                Marks2[( i - 7 ) * 4 + 3] = CenterY - y_e;
            }
        }

        canvas.drawLines(Marks,MarkPaint);
        canvas.drawLines(Marks2,MarkPaint);


        Paint TextPaint = new Paint();
        TextPaint.setAntiAlias(true);
        TextPaint.setTextAlign(Paint.Align.CENTER);
        TextPaint.setTextSize(60);
        TextPaint.setColor(Color.BLACK);

        for(int i = 0 ;i < 12;i++)
        {
            int degree = i * 30;
            int x_s = (int) (Math.sin(Math.toRadians(degree)) * ( R1 - 50 ));
            int y_s = (int) (Math.cos(Math.toRadians(degree)) * ( R1 - 50 ));

            String str = "";
            if(i == 0)
            {
                str = "12";
            }
            else{
                str = String.valueOf(i);
            }

            Paint.FontMetrics fm = TextPaint.getFontMetrics();
            canvas.drawText(str,CenterX + x_s,CenterY - y_s + (fm.descent - fm.ascent) / 2 - fm.descent,TextPaint);
        }

        /*
         获取当前时间
         */
        long time = System.currentTimeMillis();
        SimpleDateFormat format = new SimpleDateFormat("HH-mm-ss");
        String str = format.format(time);
        String[] Hour_Min_Second = str.split("-");

        Paint drawPaint = new Paint();
        drawPaint.setColor(Color.BLACK);
        drawPaint.setStyle(Paint.Style.FILL);

        /*
        计算针的角度
         */
        int hour = Integer.valueOf(Hour_Min_Second[0]) % 12;
        int min = Integer.valueOf(Hour_Min_Second[1]) % 60;
        int second = Integer.valueOf(Hour_Min_Second[2]) % 60;

        float degree_Hour = hour * 30 + min * 0.5f;
        float degree_Min = min * 360 / 60;
        float degree_Second = second * 360 / 60;

        /*
        时针
         */
        canvas.rotate(degree_Hour,width/2,height/2);
        canvas.drawRect(width / 2 - 10,height / 2 - R1 / 2,width / 2 + 10,height / 2 + 40,drawPaint);

        /*
        分针
         */
        canvas.rotate(360 - degree_Hour,width/2,height/2);
        canvas.rotate(degree_Min,width/2,height/2);
        canvas.drawRect(width / 2 - 10,height / 2 - R1 + 80,width / 2 + 10,height / 2 + 40,drawPaint);

        /*
        秒针
         */
        drawPaint.setColor(Color.RED);
        canvas.rotate(360 - degree_Min,width/2,height/2);
        canvas.rotate(degree_Second,width/2,height/2);
        canvas.drawRect(width / 2 - 5,height / 2 - R1 + 40,width / 2 + 5,height / 2 + 50,drawPaint);

        invalidate();

    }
}