Android  view自定义实现动态进度条

public class ColorProgressBar extends View{
  //下面这两行在本demo中没什么用，只是前几天看别人的代码时学到的按一定尺寸，设置其他尺寸的方式，自动忽略或者学习一下也不错
//  private int defaultStepIndicatorNum= (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,40,getResources().getDisplayMetrics());
//  int mCircleRadius=0.28f*defaultStepIndicatorNum;


  //布局的宽高
  private int mWidth;
  private int mHeight;
  //直径
  private int mDiameter=500;

  //底层圆画笔
  private Paint mPaintbg;
  //顶层圆的画笔
  private Paint mPaintft;
  //周围线的画笔
  private Paint mPaintLine;

  //外层线条的长度
  private int mLongItem=dip2px(20);
  //线条与圆的间距
  private int mDistanceItem=dip2px(10);
  //进度条的最大宽度（取底层进度条与顶层进度条宽度最大的）
  private int mProgressWidth;

  //底层圆的颜色
  private int mBackColor;
  //顶层圆的颜色
  private int mFrontColor;
  //底层圆、顶层圆的宽度
  private float mBackWidth;
  private float mFrontWidth;
  //设置进度
  private float currentvalue;
  //通过动画演示进度
  private ValueAnimator animator;
  private int curvalue;



  public ColorProgressBar(Context context) {
    this(context,null,0);
  }

  public ColorProgressBar(Context context, AttributeSet attrs) {
    this(context, attrs,0);
  }

  public ColorProgressBar(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    TypedArray ta=context.obtainStyledAttributes(attrs, R.styleable.ColorProgressBar);
    mBackColor= ta.getColor(R.styleable.ColorProgressBar_back_color, Color.BLACK);
    mFrontColor=ta.getColor(R.styleable.ColorProgressBar_front_color,mBackColor);
    mBackWidth=ta.getDimension(R.styleable.ColorProgressBar_back_width,dip2px(10));
    mFrontWidth=ta.getDimension(R.styleable.ColorProgressBar_front_width,dip2px(10));
    mProgressWidth=mBackWidth>mFrontWidth?(int)mBackWidth:(int)mFrontWidth;
    //注意释放资源
    ta.recycle();
    init();
  }

  /**
   * 都是画笔初始化
   */
  private void init() {
    mPaintbg=new Paint(Paint.ANTI_ALIAS_FLAG);
    mPaintbg.setStrokeWidth(mProgressWidth);
    mPaintbg.setColor(mBackColor);
    mPaintbg.setStrokeCap(Paint.Cap.ROUND);
    mPaintbg.setStyle(Paint.Style.STROKE);

    mPaintft=new Paint(Paint.ANTI_ALIAS_FLAG);
    mPaintft.setColor(mFrontColor);
    mPaintft.setStyle(Paint.Style.STROKE);
    mPaintft.setStrokeWidth(mFrontWidth);
    mPaintft.setStrokeCap(Paint.Cap.ROUND);

    mPaintLine=new Paint(Paint.ANTI_ALIAS_FLAG);
    mPaintLine.setColor(Color.BLACK);
    mPaintLine.setStrokeWidth(5);

  }

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
//   宽度=高度=（长指针+指针与圆盘的间距+进度条的粗细+半径）*2
    Log.e("测量数据","LongItem："+mLongItem+"mDistanceItem:"+mDistanceItem+"mProgressWidth:"+mProgressWidth+"mDiameter:"+mDiameter/2);
    mWidth=(int)2*(mLongItem+mDistanceItem+mProgressWidth*2+mDiameter/2);
    mHeight=(int)2*(mLongItem+mDistanceItem+mProgressWidth*2+mDiameter/2);
    Log.e("自定义View","高度"+mHeight+"宽度"+mWidth);
    setMeasuredDimension(mWidth,mHeight);
  }


  @Override
  protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    //绘制底层圆弧，矩形的具体计算见图片
    canvas.drawArc(new RectF(mProgressWidth/2+mDistanceItem+mLongItem,mProgressWidth/2+mDistanceItem+mLongItem,mWidth-mProgressWidth/2-mDistanceItem-mLongItem,mHeight-mProgressWidth/2-mDistanceItem-mLongItem),0,360,true,mPaintbg);
//    SweepGradient gradient=new SweepGradient();
    //绘制边缘线
    canvas.save();
    canvas.rotate(144,mWidth/2,mHeight/2);
    for(int i=0;i<=30;i++){
      canvas.rotate(-9,mWidth/2,mHeight/2);
      if(i%5==0){
        canvas.drawLine(mWidth/2,5,mWidth/2,mLongItem,mPaintbg);
      }else {
        canvas.drawLine(mWidth/2,25,mWidth/2,mLongItem,mPaintLine);
      }
    }

    canvas.restore();
    //给画笔设置渐变
    SweepGradient sweepGradient=new SweepGradient(mWidth/2,mHeight/2,Color.RED,Color.YELLOW);
    mPaintft.setShader(sweepGradient);
    //绘制顶层圆弧，currentvalue在改变时呈现动态效果
    canvas.drawArc(new RectF(mProgressWidth/2+mDistanceItem+mLongItem,mProgressWidth/2+mDistanceItem+mLongItem,mWidth-mProgressWidth/2-mDistanceItem-mLongItem,mHeight-mProgressWidth/2-mDistanceItem-mLongItem),135,currentvalue,false,mPaintft);
    mPaintft.setTextSize(100);
    mPaintft.setTextAlign(Paint.Align.CENTER);
    //绘制文本
    canvas.drawText(String.format("%.0f",currentvalue),mWidth/2,mHeight/2+50,mPaintft);
    invalidate();
  }

  /**
   * 设置动画
   * @param value
   */
  public void setCurrentValue(float value){
//    currentvalue=value;
    animator=ValueAnimator.ofFloat(currentvalue,value);
    animator.setDuration(3000);
    animator.setTarget(currentvalue);
    animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
      @Override
      public void onAnimationUpdate(ValueAnimator valueAnimator) {
        currentvalue= (float) valueAnimator.getAnimatedValue();
        curvalue=curvalue/10;
      }
    });
    animator.start();

  }
  private int dip2px(float dip){
    float density=getContext().getResources().getDisplayMetrics().density;
    return (int)(dip*density+0.5f);
  }
}

 @Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.colorprogressbar);
    mBtStart1= (Button) findViewById(R.id.bt1);

    bar1= (ColorProgressBar) findViewById(R.id.cp1);

    mBtStart1.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        bar1.setCurrentValue(270);
      }
    });

  }

 <declare-styleable name="ColorProgressBar">
    <attr name="back_color" format="color"></attr>
    <attr name="front_color" format="color"></attr>
    <attr name="back_width" format="dimension"></attr>
    <attr name="front_width" format="dimension"></attr>
  </declare-styleable>

<LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <Button
      android:id="@+id/bt1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="start1"/>

    <com.demo.demo.networkdemo.colorprogressbar.widget.ColorProgressBar
      android:id="@+id/cp1"
      android:layout_width="232dp"
      android:layout_height="match_parent"
      android:layout_gravity="center_horizontal"
      app:back_color="@color/colorPrimary"
      app:front_color="@color/colorAccent"
      android:background="@mipmap/ic_launcher"/>


  </LinearLayout>