話不多說，先上效果圖

迴圈旋轉的狀態

專案結構

一個Sample包，一個Lib包。Lib包裡面其實只有一個累，很多內容都在素材檔案裡，比較建議把內容複製出來，貼到自己的專案中

主類:

public class MainActivity extends ActionBarActivity {


    CircleProgressView mCircleView;
    Switch mSwitchSpin;
    Switch mSwitchShowUnit;
    SeekBar mSeekBar;
    SeekBar mSeekBarSpinnerLength;

    @Override
 

    protected void onCreate(Bundle savedInstanceState) {


        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            WebView.setWebContentsDebuggingEnabled(true);
        }

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mCircleView = (CircleProgressView) findViewById(R.id.circleView);
        mCircleView.setMaxValue(100
 
);
        mCircleView.setUnit("%");
        mCircleView.setValue(0);

        //Setup Switch
        mSwitchSpin = (Switch) findViewById(R.id.switch1);
        mSwitchSpin.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged
 
(CompoundButton buttonView, boolean isChecked) {
                if (isChecked) {
                    mCircleView.spin();
                } else {
                    mCircleView.stopSpinning();
                }
            }
        });

        mSwitchShowUnit = (Switch) findViewById(R.id.switch2);
        mSwitchShowUnit.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    mCircleView.setShowUnit(isChecked);
            }
        });

        //Setup SeekBar
        mSeekBar = (SeekBar) findViewById(R.id.seekBar);
        mSeekBar.setMax(100);
        mSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {

            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                mCircleView.setValueAnimated(seekBar.getProgress(),1500);
                mSwitchSpin.setChecked(false);
            }
        });

        mSeekBarSpinnerLength = (SeekBar) findViewById(R.id.seekBar2);
        mSeekBarSpinnerLength.setMax(360);
        mSeekBarSpinnerLength.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {

            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                mCircleView.setSpinningBarLength(seekBar.getProgress());
            }
        });


    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
//        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
//        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
//        if (id == R.id.action_settings) {
//            return true;
//        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onStart() {
        super.onStart();
        mCircleView.setValue(0);
        mCircleView.setValueAnimated(0);
    }
}

分析:
一個CircleProgressView自定義控制元件，2個SeekBar來控制進度條的百分比，以及長度，2個Switch用於切換顯示內容，和一堆顯示的TextView

可以在OnStart()呼叫setValue()方法，來給進度條賦值。而內部實現也是Handle傳參的一系列操作

    /**
     * Set the value of the circle view without an animation.
     * Stops any currently active animations.
     */
    public void setValue(float _value) {
        Message msg = new Message();
        msg.what = AnimationMsg.SET_VALUE.ordinal();
        msg.obj = new float[]{_value, _value};
        mAnimationHandler.sendMessage(msg);
    }

在HandleMessage方法裡又呼叫setValue(msg, circleView);
最終實現的是setValue(Message msg, CircleProgressView _circleView)方法

   private void setValue(Message msg, CircleProgressView _circleView) {
            _circleView.mValueFrom = _circleView.mValueTo;
            _circleView.mCurrentValue = _circleView.mValueTo = ((float[]) msg.obj)[0];
            _circleView.mAnimationState = AnimationState.IDLE;
            _circleView.invalidate();
        }

所以，你在程式碼操作的過程中，可以肆意呼叫SetValue()方法，不用在意會對其他部分的內容產生影響。

Sample程式碼裡的 mSeekBarSpinnerLength.setMax(360);就等於mCircleView.setSpinningBarLength(seekBar.getProgress());給環狀的SpinningBar傳一個int的值讓他呈現出一個角度為seekBar.getProgress()/360的圖形。當然你傳入的數值<360時，SeekBar拉到底了也不會成為整圓 那麼>360的話只要到達360圓就已經呈現出來了，多餘的值將沒有效果。
效果如圖：

然後我們來看下核心類CircleProgressView

public class CircleProgressView extends View 繼承於View

然後洋洋灑灑1300+行的程式碼，我就不一一分析了，一些是畫的一些是用的，亟亟就不做過多解釋了，自己可以看原始碼，為了用那我們來看下一些配置

    //尺寸引數
    private int mLayoutHeight = 0;
    private int mLayoutWidth = 0;
    private int mFullRadius = 100;
    private int mCircleRadius = 80;
    private int mBarWidth = 40;
    private int mRimWidth = 40;
    private int mTextSize = 20;
    private float mContourSize = 1;
    private float mTextScale = 1;
    private float mUnitScale = 1;

對圖形的整個大小啊，半徑啊，字型的大小啊等進行設定。

    //顏色
    private final int mBarColorStandard =  0xff009688; //stylish blue
    private int mContourColor = 0xAA000000;
    private int mSpinnerColor = mBarColorStandard; //stylish blue
    private int mFillColor = 0x00000000;  //transparent
    private int mRimColor = 0xAA83d0c9;
    private int mTextColor = 0xFF000000;
    private int mUnitColor = 0xFF000000;
    private int[] mBarColors = new int[]{
            mBarColorStandard, //stylish blue
            mBarColorStandard, //stylish blue
    };

顏色的設定，圓的顏色，字的顏色等

  private float mSpinSpeed = 2.8f; 動畫的滾動速度