一个Button变成进度条的特效

就是一个按钮的特效：可以根据自己的需求修改我们的类颜色效果都可以改变的
图一：

图二：

图三：

第一步：写你的Button样式

package com.example.xiaona.mycompany.attention;

import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.drawable.GradientDrawable;
import android.util.AttributeSet;
import android.view.animation.LinearInterpolator;

import com.example.xiaona.mycompany.R;


/**
 * Created by tong.zhang on 2017/12/1.
 */

public class  NbButton extends android.support.v7.widget.AppCompatButton {

    private int width;
    private int heigh;

    public GradientDrawable backDrawable;

    private boolean isMorphing;
    private int startAngle;

    private Paint paint;

    private ValueAnimator arcValueAnimator;

    public NbButton(Context context) {
        super(context);
        init(context);
    }

    public NbButton(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context);
    }

    public NbButton(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context);
    }

    private void init(Context context) {
        isMorphing=false;

        backDrawable=new GradientDrawable();
        int colorDrawable=context.getResources().getColor(R.color.blue);
        backDrawable.setColor(colorDrawable);
        backDrawable.setCornerRadius(120);
        setBackground(backDrawable);
        paint=new Paint();
        paint.setColor(getResources().getColor(R.color.white));
        paint.setStrokeWidth(4);
        paint.setStyle(Paint.Style.STROKE);
        paint.setTextSize(2);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int widthMode=MeasureSpec.getMode(widthMeasureSpec);
        int widthSize=MeasureSpec.getSize(widthMeasureSpec);
        int heighMode=MeasureSpec.getMode(heightMeasureSpec);
        int heighSize=MeasureSpec.getSize(heightMeasureSpec);
        if (widthMode==MeasureSpec.EXACTLY){
            width=widthSize;
        }
        if (heighMode==MeasureSpec.EXACTLY){
            heigh=heighSize;
        }
    }

    public void startAnim(){
        isMorphing=true;
        setTag(getText());
        setText("");
        ValueAnimator valueAnimator=ValueAnimator.ofInt(width,heigh);

        valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                int value= (int) animation.getAnimatedValue();
                int leftOffset=(width-value)/2;
                int rightOffset=width-leftOffset;
                backDrawable.setBounds(leftOffset,0,rightOffset,heigh);
            }
        });
        ObjectAnimator objectAnimator=ObjectAnimator.ofFloat(backDrawable,"cornerRadius",120,heigh/2);

        AnimatorSet animatorSet=new AnimatorSet();
        animatorSet.setDuration(500);
        animatorSet.playTogether(valueAnimator,objectAnimator);
        animatorSet.start();

        //画中间的白色圆圈

        showArc();
    }
    public void gotoNew(){
        isMorphing=false;
        arcValueAnimator.cancel();
        setVisibility(GONE);
    }



    public void regainBackground(){
        //setVisibility(VISIBLE);
        backDrawable.setBounds(0,0,width,heigh);
        backDrawable.setCornerRadius(24000);


        ValueAnimator valueAnimator=ValueAnimator.ofInt(heigh,width);

        valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                int value= (int) animation.getAnimatedValue();

                int leftOffset=(width-value)/2;
                int rightOffset=width-leftOffset;

                backDrawable.setBounds(leftOffset,0,rightOffset,heigh);
            }
        });
        ObjectAnimator objectAnimator=ObjectAnimator.ofFloat(backDrawable,"cornerRadius",120,heigh/2);

        AnimatorSet animatorSet=new AnimatorSet();
        animatorSet.setDuration(500);
        animatorSet.playTogether(valueAnimator,objectAnimator);
        animatorSet.start();
        //setBackground(backDrawable);
        setText((String) getTag());
        isMorphing=false;
    }

    private void showArc() {
        arcValueAnimator=ValueAnimator.ofInt(0,1080);
        arcValueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                startAngle= (int) animation.getAnimatedValue();
                invalidate();
            }
        });
        arcValueAnimator.setInterpolator(new LinearInterpolator());
        arcValueAnimator.setRepeatCount(ValueAnimator.INFINITE);
        arcValueAnimator.setDuration(3000);
        arcValueAnimator.start();
    }

    @Override
    protected void onDraw(final Canvas canvas) {
        super.onDraw(canvas);

       if (isMorphing==true){
           final RectF rectF=new RectF(getWidth()*5/12,getHeight()/2-getWidth()/12,getWidth()*7/12,getHeight()/2+getWidth()/12);
           canvas.drawArc(rectF,startAngle,270,false,paint);
       }
    }
}

第二步：你的xml按钮引用你包下面的写好的按钮类

<com.example.xiaona.mycompany.attention.NbButton
          android:id="@+id/attention"
          android:textSize="28px"
          android:layout_alignParentRight="true"
          android:layout_width="122px"
          android:layout_height="50px"
          android:padding="2px"
          android:text="+关注"
          android:textColor="@color/white"
          android:layout_centerVertical="true"
          />

第三步：在你的Activity里面调用 声明按钮，获取findViewById(R.id.attention);

   private NbButton attention;
   attention = itemView.findViewById(R.id.attention);

第3.1步：点击的时候调用样式

holder.attention.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) 
                holder.attention.startAnim();
                holder.attention.postDelayed(new Runnable() {
                    @SuppressLint("ResourceAsColor")
                    @Override
                    public void run() {
                        holder.attention.backDrawable.setColor(R.color.white);
                        holder.attention.setTag("已关注");
                        holder.attention.regainBackground();
                    }
                },2500);
            }
        });