第一步：创建attrs文件夹，自定义属性：

第二步：自定义View：

/** * Created by Michael on 2019/11/1. */ public class MyProgress extends View {   private int outColor;  private int innerColor;  private int textColor;  private float borderWidth;  private int textSize;  private Paint mOutPaint;  private Paint mInnerPaint;  private Paint mTextPaint;  private float percent;  private int p;   public MyProgress(Context context) {    this(context,null);  }   public MyProgress(Context context, @Nullable AttributeSet attrs) {    this(context, attrs,0);  }   public MyProgress(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {    super(context, attrs, defStyleAttr);    TypedArray array = context.obtainStyledAttributes(attrs,R.styleable.MyProgress);    outColor = array.getColor(R.styleable.MyProgress_out_color, Color.GREEN);    innerColor = array.getColor(R.styleable.MyProgress_inner_color, Color.BLUE);    textColor = array.getColor(R.styleable.MyProgress_text_color, Color.BLACK);    borderWidth = array.getDimension(R.styleable.MyProgress_border_width,10);    textSize = array.getDimensionPixelSize(R.styleable.MyProgress_text_size,20);    array.recycle();    init();    }   private void init() {    mOutPaint = new Paint();    mOutPaint.setAntiAlias(true);    mOutPaint.setDither(true);    mOutPaint.setStyle(Paint.Style.STROKE);    mOutPaint.setStrokeWidth(borderWidth);    mOutPaint.setColor(outColor);     mInnerPaint = new Paint();    mInnerPaint.setAntiAlias(true);    mInnerPaint.setDither(true);    mInnerPaint.setStyle(Paint.Style.STROKE);    mInnerPaint.setStrokeWidth(borderWidth);    mInnerPaint.setColor(innerColor);     mTextPaint = new Paint();    mTextPaint.setAntiAlias(true);    mTextPaint.setDither(true);    mTextPaint.setStyle(Paint.Style.FILL);    mTextPaint.setTextSize(textSize);    mTextPaint.setColor(textColor);     percent = 0;    p = 100;  }   @Override  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {    int widthMode = MeasureSpec.getMode(widthMeasureSpec);    int heightMode = MeasureSpec.getMode(heightMeasureSpec);    int width = 0,height =0;    if (widthMode == MeasureSpec.AT_MOST){     }else{      width = MeasureSpec.getSize(widthMeasureSpec);    }    if (heightMode == MeasureSpec.AT_MOST){     }else{      height = MeasureSpec.getSize(heightMeasureSpec);    }    setMeasuredDimension(width>height?height:width,width>height?height:width);  }   @Override  protected void onDraw(Canvas canvas) {    super.onDraw(canvas);    int rWidth = getWidth()>getHeight()?getHeight():getWidth();    int rHeight = getWidth()>getHeight()?getHeight():getWidth();    //int rWidth = getWidth();    //int rHeight = getHeight();     float radius = rWidth/2 - borderWidth/2;    canvas.drawCircle(rWidth/2,rHeight/2,radius,mOutPaint);     RectF r = new RectF(borderWidth/2,borderWidth/2,        rWidth-borderWidth/2,rHeight-borderWidth/2);    canvas.drawArc(r,0,360*percent,false,mInnerPaint);     String s1 = (int)(percent*100) + "%";    Rect r2 = new Rect();    mTextPaint.getTextBounds(s1,0,s1.length(),r2);    int tWidth = r2.width();    int tHeight = r2.height();    Paint.FontMetricsInt fontMetricsInt = new Paint.FontMetricsInt();    int dy = (fontMetricsInt.bottom-fontMetricsInt.top)/2-fontMetricsInt.bottom;    int baseLine = tHeight/2+dy+rHeight/2-tHeight/2;    int x0 = rWidth/2-tWidth/2;    canvas.drawText(s1,x0,baseLine,mTextPaint);  }   public void setProgress(float percent,int value){    this.percent = percent;    invalidate();  }  }

然后在布局中使用：

在activity中使用属性动画完成效果：

public class MainActivity extends AppCompatActivity {   @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    final MyProgress progress = findViewById(R.id.progress);    ValueAnimator animator = ValueAnimator.ofInt(0,5000);    animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {      @Override      public void onAnimationUpdate(ValueAnimator animation) {        float p = animation.getAnimatedFraction();        int value = (int)animation.getAnimatedValue();        progress.setProgress(p,value);      }    });    animator.setDuration(10000);    animator.start();  }  }

如果我们改动一下代码：

//int rWidth = getWidth();//int rHeight = getHeight();