Android自定义控件实现带文本与数字的圆形进度条

anvas.clipRect(0, 0, mWidth, mHeight / 2 + radius - textHeight * 3 / 4);

final CustomCircleBar circle=(CustomCircleBar)findViewById(R.id.win_home);
circle.setPercent(10);
circle.setCustomText("呵呵");
circle.setProgessColor(getResources().getColor(R.color.blue));
final Random random=new Random();
circle.setOnClickListener(new View.OnClickListener(){
 @Override
 public void onClick(View v){
 circle.setPercent(random.nextInt(100));
 }
});

public class CustomCircleBar extends View {
 private Context context;
 /**
 * 进度值
 */
 private int percent;
 /**
 * 颜色值
 */
 private int mProgessColor;
 /**
 * 下边的文字名称
 */
 private String mCustomText;
 /**
 * 外圈圆环的画笔
 */
 private Paint paintBar = new Paint();
 /**
 * 下边文字的画笔
 */
 private Paint paintText = new Paint();
 /**
 * 动态获取属性值
 */
 private TypedValue typedValue;
 /**
 * 先加速后减速
 */
 DecelerateInterpolator mDecelerateInterpolator = new DecelerateInterpolator();
 /**
 * 动画持续时间
 */
 private int duration = 10;
 private int curTime = 0;
 public CustomCircleBar(Context context) {
 super(context);
 this.context=context;
 init();
 }
 
 public CustomCircleBar(Context context, AttributeSet attrs) {
 super(context, attrs);
 this.context=context;
 init();
 }
 
 public CustomCircleBar(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);
 this.context=context;
 init();
 }
 
 
 
 public void setPercent(int percent) {
 this.percent = percent;
 /*isShown()：Returns the visibility of this view and all of its ancestors*/
 if (isShown()) {
  /**
  * 设置进度后重新开始一次动画
  */
  curTime=0;
  this.invalidate();
 }
 }
 
 public void setProgessColor(int mProgessColor) {
 this.mProgessColor = mProgessColor;
 if (isShown()) {
  this.invalidate();
 }
 }
 
 
 public void setCustomText(String mCustomText) {
 this.mCustomText = mCustomText;
 }
 
 private Handler mHandler = new Handler();
 private Runnable mAnimation = new Runnable() {
 @Override
 public void run() {
  if (curTime < duration) {
  curTime++;
  /** 导致重绘，调用onDraw，onDraw最后调用
   * mHandler.postDelayed(mAnimation, 20);更新进度条，界面重绘
   * 每次20毫秒，绘制10次，因此动画时间200毫秒
   */
  CustomCircleBar.this.invalidate();
  }
 }
 };
 
 private void init() {
 /**
  * 数据初始化，没有设置属性时候的默认值
  */
 percent = 0;
 mProgessColor=Color.rgb(95,112,72);
 mCustomText="Home";
 typedValue=new TypedValue();
 context.getTheme().resolveAttribute(R.attr.maintextclor,typedValue,true);
 }
 
 
 
 @Override
 protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 float mWidth = getWidth();
 float mHeight = getHeight();
 /**
  * 下边是进度条画笔的设置
  */
 /** Restores the paint to its default settings. */
 paintBar.reset();
 /**
  * 圆环宽度4个像素
  */
 paintBar.setStrokeWidth(4);
 /**
  * 空心圆环而非填充的额扇形
  */
 paintBar.setStyle(Paint.Style.STROKE);
 paintBar.setAntiAlias(true);
 paintBar.setColor(mProgessColor);
 /**
  * 调整下不透明度，使边框弧和进度条区分开
  */
 paintBar.setAlpha(80);
 /**
  * 接下来是文字画笔的设置
  */
 paintText.setTextSize(20);
 paintText.setColor(getResources().getColor(typedValue.resourceId));
 paintText.setStyle(Paint.Style.STROKE);
 paintText.setAntiAlias(true);
 /**
  * 从中间开始绘制文本
  */
 paintText.setTextAlign(Paint.Align.CENTER);
 /**
  * 测量文字大小
  */
 Paint.FontMetrics fontMetrics = paintText.getFontMetrics();
 /**
  * 计算文字高度
  */
 float textHeight = fontMetrics.bottom - fontMetrics.top;
 /**
  * 计算圆的半径
  */
 float radius = Math.min(mWidth, mHeight) / 2 - 10;
 /* ❑ save：用来保存Canvas的状态。save之后，可以调用Canvas的平移、放缩、旋转、错切、裁剪等操作。
  ❑ restore：用来恢复Canvas之前保存的状态。防止save后对Canvas执行的操作对后续的绘制有影响。*/
 /*保存画布，绘制进度条*/
 canvas.save();
 /*clipRect：该方法用于裁剪画布，也就是设置画布的显示区域
 调用clipRect()方法后，只会显示被裁剪的区域，之外的区域将不会显示 */
 canvas.clipRect(0, 0, mWidth, mHeight / 2 + radius - textHeight * 3 / 4);
 /*因为clipRect的原因，外边的圆环下边留个缺口绘制文字*/
 canvas.drawCircle(mWidth / 2, mHeight / 2, radius, paintBar);
 
 /**
  * 三角函数计算，下方缺口扇形的角度的一半
  */
 float theta_offset = (float) Math.acos((radius - textHeight / 2) / radius);
 /**
  * 大弧围成的扇形的角度
  */
 float theta_full = 360 - 2 * theta_offset;
 /**
  * 进度值围成的弧对应的角度
  */
 float thetaProcess = mDecelerateInterpolator.getInterpolation(1.0f * curTime / duration) * percent * theta_full / 100;
 /**
  * 设置进度值颜色完全不透明
  */
 paintBar.setAlpha(255);
 paintBar.setColor(mProgessColor);
 /**
  * 注意弧形的起始角度，下边因显示文字导致圆环断开成一条弧，弧有左右两个端点，从左端点开始画弧
  */
 canvas.drawArc(new RectF(mWidth / 2 - radius, mHeight / 2 - radius, mWidth / 2 + radius, mHeight / 2 + radius), theta_offset+90, thetaProcess, false, paintBar);
 /**
  * 恢复画布
  */
 canvas.restore();
 /**
  * 开始绘制文字
  */
 paintText.setTextSize(20);
 fontMetrics = paintText.getFontMetrics();
 float textBaseLineOffset = (fontMetrics.bottom - fontMetrics.top) / 2 - fontMetrics.bottom;
 canvas.drawText(mCustomText, mWidth / 2, mHeight / 2 + radius - textHeight / 2 + textBaseLineOffset, paintText);
 
 /**
  * 绘制百分号
  */
 paintText.setTextSize(mHeight * 1 / 8);
 fontMetrics = paintText.getFontMetrics();
 textBaseLineOffset = (fontMetrics.bottom - fontMetrics.top) / 2 - fontMetrics.bottom;
 canvas.drawText("%", mWidth / 2, mHeight / 2 + radius / 3 + textBaseLineOffset, paintText);
 
 /**
  * 绘制百分比
  */
 paintText.setTextSize(mHeight * 3 / 8);
 canvas.drawText("" + (int)(percent*mDecelerateInterpolator.getInterpolation(1.0f * curTime / duration)), mWidth / 2, mHeight / 2, paintText);
 /**
  * 20毫秒后执行动画
  */
 mHandler.postDelayed(mAnimation, 20);
 }
}