如何在Java

Question

我遇到了ImageView之一的动作问题。更具体地说，我需要它向下移动屏幕，然后以某种方式在顶部备份，以便它可以再次下降。

void settingCage1(){
    Random X = new Random();
    int xx = X.nextInt(30)+1; //this is to set Random location of cage on X axis
    final ImageView cage = (ImageView)findViewById(R.id.cage1);
    DisplayMetrics dm = getApplicationContext().getResources().getDisplayMetrics();
    float dpHeight = dm.heightPixels;// / dm.density;
    float dpWidth = dm.widthPixels;// / dm.density;
    int wid2;
    int het2;
    het2 = (int) ((dpHeight*0.16));
    wid2 = (int) ((dpWidth*0.16));
    cage.setMaxHeight(het2);
    cage.setMaxWidth(wid2);
    RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) cage.getLayoutParams();
    RelativeLayout.LayoutParams llp = (RelativeLayout.LayoutParams) cage.getLayoutParams();
    lp.leftMargin = (int) ((dpWidth * (50)/100)); //setting the location of Cage anywhere on the left half of the screen

    llp.bottomMargin = (int) ((dpHeight * 0.626)); //this is where it will be falling to
    lp.topMargin = RelativeLayout.ALIGN_PARENT_TOP; //this is the cage's starting pos.
        cage.layout(lp.leftMargin, RelativeLayout.ALIGN_PARENT_START, 0, 0); 
        cage.animate().translationY(llp.bottomMargin).setDuration(4000); //this moves the cage to the desired area and a reasonable duration.

}

此代码到目前为止有效！然而，它只做了一半的工作，我需要它回到顶部，并不断下降。我试过这个方法：

for (int i =0; i<6; i++) {
    cage.layout(lp.leftMargin, RelativeLayout.ALIGN_PARENT_START, 0, 0);
    cage.animate().translationY(llp.bottomMargin).setDuration(4000);
    cage.setVisibility(View.GONE);
    cage.animate().translationY(lp.topMargin);
    cage.setVisibility(View.VISIBLE);
}

然而，这不起作用，并且笼子设置在一个位置而不移动。 以下是笼子和父亲的XML：

<?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="0px"
    android:paddingLeft="0px"
    android:paddingRight="0px"
    android:paddingTop="0px"
    tools:context="com.Cage.Game"
    android:id="@+id/prnt">
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:minWidth="50dp"
            android:minHeight="50dp"
            android:src="@drawable/cageday"
            android:adjustViewBounds="true"
            android:id="@+id/cage1"/>
    </RelativeLayout>