Android objectanimator不做补间动画

Question

作为教程，当我按下它时，我想使用线性动画在屏幕上移动按钮。但是，我使用的objectanimator直接进入最终值，没有补间。但只有通过Onclick事件调用它。在OnCreate直接调用它时工作正常。我错过了什么？

这是我的代码:(对于调试，目标对象替换为＆＃39; this＆＃39;以显示被调用的getter和setter）

package com.example.tweakerslayout;

import android.animation.ObjectAnimator;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.animation.LinearInterpolator;
import android.widget.Button;



public class MainActivity extends ActionBarActivity {

    float y =500;

    public float getY(){
        System.out.println("getY was called");
        return y;

    }

    public void setY(float value){
        System.out.println("Y setter called with value: " + value);
        y = value;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Animate();

        final Button myButton = (Button)findViewById(R.id.myButton);
        myButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Animate2();
            }
        });
    }

    public void Animate(){
        ObjectAnimator animY = ObjectAnimator.ofFloat(MainActivity.this, "y", 100f);
        animY.setInterpolator(new LinearInterpolator());
        animY.setDuration(2000);
        animY.start();
    }

    public void Animate2(){
        ObjectAnimator animY = ObjectAnimator.ofFloat(MainActivity.this, "y", 300f);
        animY.setInterpolator(new LinearInterpolator());
        animY.setDuration(2000);
        animY.start();
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

我的xml activity_main：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="16dp"
    android:paddingRight="16dp">

    <TextView
        android:id="@+id/myText"
        android:text="Hello, we're just testing" android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <Button
        android:id="@+id/myButton"
        android:text="Button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</RelativeLayout>

Android Manifest：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.tweakerslayout" >

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Styles.xml：

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
    </style>

</resources>

打印输出 - 最后几行是我点击按钮的时候：

05-23 12:26:09.417  25524-25524/com.example.tweakerslayout D/OpenGLRenderer﹕ Enabling debug mode 0
05-23 12:26:09.447  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 480.0
05-23 12:26:09.507  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 467.0
05-23 12:26:09.517  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 463.6
05-23 12:26:09.527  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 460.4
05-23 12:26:09.537  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 457.0
05-23 12:26:09.557  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 453.8
05-23 12:26:09.577  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 450.4
05-23 12:26:09.587  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 447.2
05-23 12:26:09.607  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 443.8
05-23 12:26:09.627  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 440.6
05-23 12:26:09.637  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 437.2
05-23 12:26:09.657  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 434.0
05-23 12:26:09.677  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 430.6
05-23 12:26:09.687  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 427.4
05-23 12:26:09.707  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 424.0
05-23 12:26:09.727  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 420.8
05-23 12:26:09.737  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 417.4
05-23 12:26:09.757  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 414.2
05-23 12:26:09.777  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 410.8
05-23 12:26:09.787  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 407.6
05-23 12:26:09.807  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 404.2
05-23 12:26:09.827  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 401.0
05-23 12:26:09.837  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 397.6
05-23 12:26:09.857  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 394.4
05-23 12:26:09.867  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 391.0
05-23 12:26:09.887  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 387.8
05-23 12:26:09.907  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 384.4
05-23 12:26:09.917  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 381.2
05-23 12:26:09.937  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 377.8
05-23 12:26:09.957  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 374.4
05-23 12:26:09.967  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 371.2
05-23 12:26:09.987  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 367.8
05-23 12:26:10.007  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 364.6
05-23 12:26:10.017  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 361.2
05-23 12:26:10.037  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 358.0
05-23 12:26:10.057  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 354.6
05-23 12:26:10.067  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 351.40002
05-23 12:26:10.087  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 348.0
05-23 12:26:10.107  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 344.8
05-23 12:26:10.117  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 341.40002
05-23 12:26:10.137  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 338.2
05-23 12:26:10.157  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 334.8
05-23 12:26:10.167  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 331.6
05-23 12:26:10.187  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 328.2
05-23 12:26:10.207  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 325.0
05-23 12:26:10.217  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 321.59998
05-23 12:26:10.237  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 318.4
05-23 12:26:10.247  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 315.0
05-23 12:26:10.267  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 311.8
05-23 12:26:10.287  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 308.4
05-23 12:26:10.297  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 305.2
05-23 12:26:10.317  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 301.8
05-23 12:26:10.337  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 298.6
05-23 12:26:10.347  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 295.2
05-23 12:26:10.367  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 292.0
05-23 12:26:10.387  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 288.59998
05-23 12:26:10.397  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 285.2
05-23 12:26:10.417  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 282.0
05-23 12:26:10.437  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 278.6
05-23 12:26:10.447  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 275.4
05-23 12:26:10.467  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 272.0
05-23 12:26:10.487  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 268.8
05-23 12:26:10.497  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 265.40002
05-23 12:26:10.517  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 262.2
05-23 12:26:10.537  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 258.8
05-23 12:26:10.547  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 255.6
05-23 12:26:10.567  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 252.20001
05-23 12:26:10.587  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 249.0
05-23 12:26:10.597  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 245.6
05-23 12:26:10.617  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 242.4
05-23 12:26:10.637  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 239.0
05-23 12:26:10.647  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 235.80002
05-23 12:26:10.667  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 232.4
05-23 12:26:10.677  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 229.20001
05-23 12:26:10.697  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 225.79999
05-23 12:26:10.717  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 222.6
05-23 12:26:10.727  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 219.19998
05-23 12:26:10.747  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 216.0
05-23 12:26:10.767  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 212.6
05-23 12:26:10.777  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 209.40002
05-23 12:26:10.797  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 206.0
05-23 12:26:10.817  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 202.80002
05-23 12:26:10.827  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 199.4
05-23 12:26:10.847  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 196.19998
05-23 12:26:10.867  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 192.79999
05-23 12:26:10.877  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 189.4
05-23 12:26:10.897  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 186.20001
05-23 12:26:10.917  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 182.80002
05-23 12:26:10.927  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 179.6
05-23 12:26:10.947  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 176.20001
05-23 12:26:10.967  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 173.0
05-23 12:26:10.977  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 169.6
05-23 12:26:10.997  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 166.4
05-23 12:26:11.007  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 163.0
05-23 12:26:11.027  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 159.80002
05-23 12:26:11.047  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 156.4
05-23 12:26:11.057  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 153.20001
05-23 12:26:11.077  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 149.79999
05-23 12:26:11.097  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 146.6
05-23 12:26:11.107  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 143.19998
05-23 12:26:11.127  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 140.0
05-23 12:26:11.147  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 136.6
05-23 12:26:11.157  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 133.40002
05-23 12:26:11.177  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 130.0
05-23 12:26:11.197  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 126.79999
05-23 12:26:11.207  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 123.399994
05-23 12:26:11.227  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 120.19998
05-23 12:26:11.247  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 116.79999
05-23 12:26:11.257  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 113.600006
05-23 12:26:11.277  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 110.20001
05-23 12:26:11.297  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 107.0
05-23 12:26:11.307  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 103.600006
05-23 12:26:11.327  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 100.20001
05-23 12:26:11.347  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 100.0
05-23 12:26:20.937  25524-25524/com.example.tweakerslayout I/System.out﹕ getY was called
05-23 12:26:20.937  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 300.0
05-23 12:26:20.957  25524-25524/com.example.tweakerslayout I/System.out﹕ Y setter called with value: 300.0