在界面顶部滑动展开的自定义FrameLayout

translationView.show();
translationView.hide();
translationView.setShadowColor(ActivityCompat.getColor(MainActivity.this, R.color.blue));//设置背景颜色

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ObjectAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.support.annotation.ColorInt;
import android.support.v4.view.MotionEventCompat;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.FrameLayout;

public class TranslationView extends FrameLayout {

private static final String TAG = "TranslationView";
private static final int DEFAULT_COLOR = 0x50000000;
private int mShadowColor = DEFAULT_COLOR;
private boolean mIsShow = false;

private View mTranslationView;

public TranslationView(Context context) {
super(context, null);
}

public TranslationView(Context context, AttributeSet attrs) {
super(context, attrs, 0);
}

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

@Override
protected void onFinishInflate() {
if (getChildCount() != 2) {
throw new IllegalStateException("only and should contain two child view");
}
mTranslationView = getChildAt(1);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
Log.d(TAG, "onMeasure");
}

@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
mTranslationView.layout(0, -mTranslationView.getHeight(), mTranslationView.getWidth(), 0);
}

@Override
protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
if (mIsShow && child == mTranslationView) {
canvas.drawColor(mShadowColor);
}
return super.drawChild(canvas, child, drawingTime);
}

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
final int action = MotionEventCompat.getActionMasked(ev);
switch (action){
case MotionEvent.ACTION_DOWN:{
if(mIsShow&&inShadow(ev)){
hide();
return true;
}
}
}
return  super.onInterceptTouchEvent(ev);
}

private boolean inShadow(MotionEvent ev) {
float x = ev.getX();
float y = ev.getY();
final float leftEdge = mTranslationView.getX();
final float rightEdge = leftEdge+mTranslationView.getWidth();
final float topEdge =mTranslationView.getHeight();
final float bottomEdge = getHeight()+topEdge;
return x > leftEdge && x < rightEdge && y > topEdge && y < bottomEdge;
}

public void show() {
if (!mIsShow) {
mIsShow = true;
ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(mTranslationView, "translationY", mTranslationView.getTranslationY(), mTranslationView.getHeight());
objectAnimator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationStart(Animator animation) {
super.onAnimationStart(animation);
invalidate();
}
});
objectAnimator.start();
}
}

public void hide() {
if (mIsShow) {
mIsShow = false;
ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(mTranslationView, "translationY", mTranslationView.getTranslationY(), -mTranslationView.getHeight());
objectAnimator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
invalidate();
}
});
objectAnimator.start();
}
}

public void setShadowColor(@ColorInt int color) {
mShadowColor = color;
}
}