Android一个自定义的进度环:ProgressChart

public class ProgressChart extends View
{

	private Context context;
	
	//圆环背景画笔
	private Paint paintBg;
	
	//圆环进度画笔
    private Paint paintProgress;
    
    //文字画笔1
    private Paint paintText1;
    
    //文字画笔2
    private Paint paintText2;
    
    // 圆环的宽度 
    private float progressWidth;  
    
    //圆环的区域
    private RectF roundRect;
    
    //文字的区域
    private Rect textRect;

    //单个字符的区域
    private Rect charRect;
    
    //绘制时每次增加的度数
    private float rotateDegree = 1.0F;
    
    //绘制开始的度数
    private float startDegree = 0.0F;
    
    //结束的度数
    private float endDegree;
    
    //背景颜色
    private int bgColor;
    
    //进度颜色
    private int progressColor;
    
    // 中间进度百分比的字符串的颜色 
    private int textColor;  
    
    //字符串的文字大小
    private float text1Size;
    
    //字符串的文字大小
    private float text2Size;
    
    //绘制的字符串
    private String text="0%";

   
    
	public ProgressChart(Context context) 
	{
		this(context, null);
	}

	public ProgressChart(Context context, AttributeSet attrs) 
	{
		this(context, attrs, 0);
	}
	
	public ProgressChart(Context context, AttributeSet attrs,int defStyleAttr) 
	{
		super(context, attrs, defStyleAttr);
		
		this.context=context;
		
		init(attrs);
	}

	private void init(AttributeSet attrs) 
	{
		TypedArray mTypedArray = context.obtainStyledAttributes(attrs,R.styleable.ProgressChart);
		
	    this.progressWidth = mTypedArray.getDimension(R.styleable.ProgressChart_progressWidth, 8);
	    this.text1Size = mTypedArray.getDimension(R.styleable.ProgressChart_textSize1, 32);
	    this.text2Size = mTypedArray.getDimension(R.styleable.ProgressChart_textSize2, 20);
	    this.bgColor = mTypedArray.getColor(R.styleable.ProgressChart_bgColor,Color.parseColor("#fff2f2f2"));
	    this.progressColor = mTypedArray.getColor(R.styleable.ProgressChart_progressColor,Color.parseColor("#fffd0000"));
	    this.textColor = mTypedArray.getColor(R.styleable.ProgressChart_txtColor,Color.parseColor("#fffd0000"));
	    
	    mTypedArray.recycle();
	    
	    this.textRect = new Rect();
	    this.charRect = new Rect();

	    this.paintBg = new Paint();
	    this.paintBg.setStyle(Paint.Style.STROKE);
	    this.paintBg.setStrokeWidth(this.progressWidth);
	    this.paintBg.setColor(this.bgColor);
	    
	    this.paintProgress = new Paint();
	    this.paintProgress.setStyle(Paint.Style.STROKE);
	    this.paintProgress.setStrokeWidth(this.progressWidth);
	    this.paintProgress.setColor(this.progressColor);
	    
	    
	    this.paintText1 = new Paint();
	    this.paintText1.setTextSize(this.text1Size);
	    this.paintText1.setTextAlign(Paint.Align.CENTER);
	    this.paintText1.setColor(this.textColor);
	    
	    this.paintText2 = new Paint();
	    this.paintText2.setTextSize(this.text2Size);
	    this.paintText2.setTextAlign(Paint.Align.CENTER);
	    this.paintText2.setColor(this.textColor);
	}
	
	public boolean setProgress(String progress)
	{
		this.text = DecimalFormat.getPercentInstance().format(Double.valueOf(progress));
	    this.startDegree = 0.0F;
	    this.endDegree = (360.0F * Float.valueOf(progress).floatValue());
	    this.rotateDegree = (this.endDegree / 40.0F);
	    
	    invalidate();
	    
		return true;
	}
	
	@Override
	protected void onDraw(Canvas canvas)
	{
		//绘制圆环背景
		canvas.drawArc(this.roundRect, 0.0F, 360.0F, false, this.paintBg);
		
		//绘制进度
	    if (this.startDegree < this.endDegree)
	    {
	    	canvas.drawArc(this.roundRect, -90.0F, this.startDegree, false, this.paintProgress);
	        this.startDegree += this.rotateDegree;
	        invalidate();
	    }
	    else
	    {
	    	canvas.drawArc(this.roundRect, -90.0F, this.endDegree, false, this.paintProgress);
	    }
	    
	    if(!TextUtils.isEmpty(this.text))
	    {
		    //绘制文字
		    this.paintText1.getTextBounds(this.text, 0, this.text.length(), this.textRect);
		    this.paintText2.getTextBounds("%", 0, 1, this.charRect);
		    
		    FontMetricsInt fontMetricsInt = this.paintText1.getFontMetricsInt();
		    float y = this.roundRect.top + (this.roundRect.bottom - this.roundRect.top - fontMetricsInt.bottom + fontMetricsInt.top) / 2.0F - 5 * fontMetricsInt.top / 5;
		    canvas.drawText(this.text.replace("%", ""), this.roundRect.centerX() - this.charRect.width() / 2, y, this.paintText1);
		    canvas.drawText("%", this.roundRect.centerX() + this.textRect.width() / 2 - this.charRect.width() / 2, y, this.paintText2);
	   }
	}

	@Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) 
    {
		this.roundRect = new RectF(this.progressWidth, this.progressWidth, w - this.progressWidth, h - this.progressWidth);
	}
	


}