listview 上滑隐藏标题栏，下滑显示标题栏

此demo实现listview上滑隐藏标题栏，下滑显示标题栏，解决了出现空白问题，添加了隐藏显示动画效果；
先上效果图：



实现逻辑：
第一步：因为此动画是在fragment写的，首先监听activity的dispatchTouchEvent（）方法，看fragment是否注册了监听，如果注册，则会执行这个监听；
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
for (MyOnTouchListener listener : onTouchListeners) {
listener.dispatchTouchEvent(ev);
}
return super.dispatchTouchEvent(ev);
}
第二步：在fragment中注册监听，在dispatchTouchEvent（）监听滑动，实现了AnimatorListener，重写了四个方法，当动画完成监听里，使改动listview位置; private boolean dispathTouchEvent(MotionEvent event) {
if (mIsAnim) {
return false;
}
final int action = event.getAction();

float x = event.getX();
float y = event.getY();

switch (action) {
case MotionEvent.ACTION_DOWN:
lastY = y;
lastX = x;
return false;
case MotionEvent.ACTION_MOVE:
//返回 int 值的绝对值
float dY = Math.abs(y - lastY);
float dX = Math.abs(x - lastX);
//判断是上滑还是下滑
boolean down = y > lastY ? true : false;
lastY = y;
lastX = x;
isUp = dX < 8 && dY > 8 && !mIsTitleHide && !down;
isDown = dX < 8 && dY > 8 && mIsTitleHide && down;

if (isUp) {
View view = this.mLayout;
float[] f = new float[2];
f[0] = 0.0F;
f[1] = -hide_title_layout.getHeight();
ObjectAnimator animator1 = ObjectAnimator.ofFloat(view, "translationY", f);//动画
animator1.setDuration(200);
animator1.start();
animator1.addListener(this);
setMarginTop(mLayout.getHeight() - hide_title_layout.getHeight());//设置listview位置
} else if (isDown) {
View view = this.mLayout;
float[] f = new float[2];
f[0] = -hide_title_layout.getHeight();
f[1] = 0F;
ObjectAnimator animator1 = ObjectAnimator.ofFloat(view, "translationY", f);
animator1.setDuration(200);
animator1.setInterpolator(new AccelerateDecelerateInterpolator());

4000
animator1.start();
animator1.addListener(this);
} else {
return false;
}
mIsTitleHide = !mIsTitleHide;
mIsAnim = true;
break;
default:
return false;
}
return false;

}设置listview距离顶部位置： RelativeLayout.LayoutParams layoutParam = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.FILL_PARENT, RelativeLayout.LayoutParams.FILL_PARENT);
layoutParam.setMargins(0, height, 0, 0);
mListView.setLayoutParams(layoutParam);
mListView.invalidate();下面附上demo地址 https://download.csdn.net/download/shanshan_1117/10297452
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