自定义伸缩 控件 带动画结束后 和开始前的回调

import android.animation.Animator;
import android.animation.IntEvaluator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.widget.LinearLayout;

import com.tongfantravel.passenger.R;


/**
 * Created by Administrator on 2016/11/15.
 */
public class StretchView extends LinearLayout {


    int contentViewId;
    int stretchViewId;
    int dutation = 300;
    private View contentView;
    private View stretchView;
    private boolean isOpen = false;
    private int stretchViewHeight;

    public void setOnStretchListener(OnStretchListener onStretchListener) {
        this.onStretchListener = onStretchListener;
    }

    private OnStretchListener onStretchListener;
    public StretchView(Context context) {
        super(context);
        init(context, null);
    }

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

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

    private void init(Context context, AttributeSet attrs) {
        setOrientation(LinearLayout.VERTICAL);
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.StretchPanel);
        contentViewId = a.getResourceId(R.styleable.StretchPanel_contentView, -1);
        stretchViewId = a.getResourceId(R.styleable.StretchPanel_stretchView, -1);
        if (contentViewId != -1) {
            contentView = LayoutInflater.from(context).inflate(contentViewId, this, false);
            setContentView(contentView);
        }
        if (stretchViewId != -1) {
            stretchView = LayoutInflater.from(context).inflate(stretchViewId, this, false);
            setStretchView(stretchView);
        }
        a.recycle();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        if (stretchViewHeight == 0) {
            stretchView.measure(widthMeasureSpec, MeasureSpec.UNSPECIFIED);
            stretchViewHeight = stretchView.getMeasuredHeight();
        }
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        closeStrtchView();
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
// closeStrtchView();
        stretchView.setFocusable(true);
    }


    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        return false;
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        return false;
    }

    public void setContentView(View mContentView) {
        if (contentView != null) {
            removeView(contentView);
        }
        this.contentView = mContentView;
        addView(mContentView);
        setOpenClickListenerOnThis(contentView);
    }

    public void setStretchView(View mStretchView) {
        if (stretchView != null)
            removeView(stretchView);

        this.stretchView = mStretchView;
        addView(mStretchView);
    }

    public interface OnStretchListener {
        void openStretchBefore();

        void closeStretchAfter();
    }

    public void setOpenClickListenerOnThis(View openClickListenerOnThis) {
// this.openClickListenerOnThis = openClickListenerOnThis;

        if (openClickListenerOnThis != null) {
            openClickListenerOnThis.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (!isOpen) {
                        openStretchView();
                    } else {
                        closeStrtchView();
                    }
                    isOpen = !isOpen;
                }
            });
        }
    }

    private void closeStrtchView() {

        ValueAnimator valueAnimator = ValueAnimator.ofInt(1, 100);
        valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            IntEvaluator intEvaluator = new IntEvaluator();

            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                float animatedFraction = animation.getAnimatedFraction();
                stretchView.getLayoutParams().height = intEvaluator.evaluate(animatedFraction, stretchViewHeight, 0);
                stretchView.requestLayout();
            }
        });
        valueAnimator.addListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animation) {

            }

            @Override
            public void onAnimationEnd(Animator animation) {
               onStretchListener.closeStretchAfter();
            }

            @Override
            public void onAnimationCancel(Animator animation) {

            }

            @Override
            public void onAnimationRepeat(Animator animation) {

            }
        });
        valueAnimator.setDuration(dutation).start();
    }

    private void openStretchView() {
        onStretchListener.openStretchBefore();
        ValueAnimator valueAnimator = ValueAnimator.ofInt(1, 100);
        valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            IntEvaluator intEvaluator = new IntEvaluator();

            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                float animatedFraction = animation.getAnimatedFraction();
                stretchView.getLayoutParams().height = intEvaluator.evaluate(animatedFraction, 0, stretchViewHeight);
                stretchView.requestLayout();
            }
        });
        valueAnimator.setDuration(dutation).start();
    }

    public void setCloseStretchView() {
        closeStrtchView();
    }
}

本文地址：https://blog.csdn.net/Victor____asd/article/details/107492529