活动小方块作业

老师，我运行的结果是mHeight0.0,  square:0

获取不了父控件的高度以及方块的高度。

xml代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:hyman="http://schemas.android.com/apk/res-auto"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"

    tools:context="com.qiaoguo.canclesquare.MainActivity">

   <LinearLayout
       android:id="@+id/lay_content"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="9"
       android:background="@drawable/lay_line"
    >

    <com.qiaoguo.canclesquare.SquareView
        android:id="@+id/square"
        android:progress="0"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />



</LinearLayout>

<LinearLayout
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1">
    <Button
        android:id="@+id/left"
        android:layout_width="0dp"
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:background="@drawable/left"
        />

    <Button
        android:id="@+id/top"
        android:layout_width="0dp"
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:background="@drawable/down"
        />
    <Button
        android:id="@+id/right"
        android:layout_width="0dp"
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:background="@drawable/right"
        />


</LinearLayout>


</LinearLayout>

java程序

public class MainActivity extends AppCompatActivity {
private float mHeight;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        SquareView square = (SquareView) findViewById(R.id.square);
        LinearLayout content = (LinearLayout) findViewById(R.id.lay_content);
       mHeight=(float) content.getBottom();
   Toast.makeText(this,"mHeight"+mHeight+"square"+square.getBottom(),Toast.LENGTH_SHORT).show();
        square.animate().translationY(mHeight).setDuration(3000).start();


    }
}