自定義錶盤

<pre name="code" class="html">package com.paad.compass;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

public class MyCompass extends View {

	private Paint criclePaint;
	private Paint markPaint;
	private Paint textPaint;
	private int degree = 0;

	public MyCompass(Context context) {
		super(context);
		// TODO Auto-generated constructor stub
		initView(context);
	}

	public MyCompass(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
		initView(context);
	}

	public MyCompass(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		// TODO Auto-generated constructor stub
		initView(context);
	}

	private void initView(Context context) {
		Resources r = context.getResources();
		criclePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
		criclePaint.setColor(r.getColor(R.color.background_color));
		criclePaint.setStrokeWidth(1);
		criclePaint.setStyle(Paint.Style.FILL_AND_STROKE);

		markPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
		markPaint.setColor(r.getColor(R.color.marker_color));

		textPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
		textPaint.setColor(r.getColor(R.color.text_color));
	}

	@Override
	protected void onDraw(Canvas canvas) {
		// TODO Auto-generated method stub
		int cx = getMeasuredWidth() / 2;
		int cy = getMeasuredHeight() / 2;
		int radius = cx;
		canvas.drawCircle(cx, cy, radius, criclePaint);
		canvas.save();//保存背景

		for (int i = 0; i < 60; i++) {
			canvas.save();//保存繪製前狀態
			int startX = cx;
			int startY = cy - radius;
			int stopX = cx;
			int stopY = startY + 10;
			int h = (int) markPaint.measureText("Y");
			String text = "";
			if (i % 15 == 0) {
				
				switch (i) {
				case 0:
					text = "12";
					break;
				case 15:
					text = "3";
					break;
				case 30:
					text = "6";
					break;
				case 45:
					text = "9";
					break;
				}
				int textH = (int) textPaint.measureText("W");
				canvas.drawText(text, startX - textH / 2, startY + 10 + 2 * h,
						textPaint);
				canvas.drawLine(startX, startY, stopX, stopY+5, markPaint);
			}else{
				canvas.drawLine(startX, startY, stopX, stopY, markPaint);
			}
			canvas.translate(0, h);

			canvas.restore();//恢復到繪製前狀態，清除上面的translate(0, h)動作。準備下一次繪繪製
			canvas.rotate(6, cx, cy);
		}
		canvas.save();
		canvas.rotate((int)degree, cx, cy);
		int h = (int) markPaint.measureText("Y");
		canvas.drawLine(cx-5, cy-radius + 25 + 3 * h, cx, cy-radius + 20 + 2 * h, markPaint);
		canvas.drawLine(cx+5, cy-radius + 25 + 3 * h, cx, cy-radius + 20 + 2 * h, markPaint);
		canvas.restore();//清除上面的canvas.rotate((int)degree, cx, cy);動作
		
		canvas.restore();//恢復到背景
		handler.sendEmptyMessageDelayed(0, 1000);
	}

	Handler handler = new Handler(){

		@Override
		public void handleMessage(Message msg) {
			// TODO Auto-generated method stub
			Log.d("tag", "degree="+degree);
			if(degree>=360){
				degree = 0;
			}
			invalidate();
			degree+=6;
		}
		
	};
	
	@Override
	protected void onLayout(boolean changed, int left, int top, int right,
			int bottom) {
		// TODO Auto-generated method stub
		super.onLayout(changed, left, top, right, bottom);
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		// TODO Auto-generated method stub
		int specW = measure(widthMeasureSpec);
		int specH = measure(heightMeasureSpec);
		int d = Math.min(specW, specH);
		setMeasuredDimension(d, d);
	}

	private int measure(int size) {
		int result = 0;
		int specMode = MeasureSpec.getMode(size);
		int specSize = MeasureSpec.getSize(size);
		if (specMode == MeasureSpec.UNSPECIFIED) {
			result = 200;
		} else {
			result = specSize;
		}
		return result;
	}
}

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <color name="background_color">#F555</color>
  <color name="marker_color">#AFFF</color>
  <color name="text_color">#AFFF</color>
</resources>