Android - 如何以一定的间隔制作图像动画？

Question

我正在参加Android编程的Coursera课程。这是我想要做的事情的例证...

这是我到目前为止的代码......

XML：

<Button
        android:id="@+id/startbutton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/leftfoot"
        android:layout_alignRight="@+id/leftfoot"
        android:onClick="startRhythmandAnimation"
        android:text="@string/start_button" />

爪哇：

public class Assignment3MainActivity extends Activity {

private View mMileTimeGoal;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_assignment3_main);
    mMileTimeGoal = findViewById(R.id.miletimegoal);
}

public void startRhythmandAnimation () {
    String MileTime = mMileTimeGoal.getContext().toString();
    String[] time_array = MileTime.split(":");
    int hours = Integer.parseInt(time_array[0]);
    int minutes = Integer.parseInt(time_array[1]);
    int seconds = Integer.parseInt(time_array[2]);
    int duration = 3600 * hours + 60 * minutes + seconds;
    int steps_per_second = 3;

    int running_rate = duration * steps_per_second;

    View rightfoot = findViewById(R.id.rightfoot);
    View leftfoot = findViewById(R.id.leftfoot);

    rightfoot.setVisibility(View.VISIBLE);
    Animation anim = AnimationUtils.makeInChildBottomAnimation(this);
    rightfoot.startAnimation(anim);

    leftfoot.setVisibility(View.VISIBLE);
    leftfoot.startAnimation(anim);
}

关于如何形成我的算法的任何想法会滑动和淡化我的右脚视图和左脚视图？

我应该使用while循环并启动某种类型的计时器吗？

Answer 1

活动

private Handler mHandler;    
private long mInterval = 1000;
private View mLeftfoot;
private Animation mFootAnim;

public void onCreate(Bundle bundle) {
   ...
   mHandler = new Handler(); //.os package class when importing
   mLeftfoot = findViewById(R.id.leftfoot);
   mFootAnim = AnimationUtils.loadAnimation(this, R.anim.foot);
   stepRecursive();
}

private void stepRecursive() {
    mHandler.postDelayed(new Runnable() {
        @Override
        public void run() {
            mLeftFoot.startAnimation(mFootAnim );
            stepRecursive();
        }
    }, mInterval);
}

/res/anim/foot.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate android:fromYDelta="0" android:toYDelta="-15" android:duration="400"/>
    <alpha android:fromAlpha="1.0" android:toAlpha="0" android:duration="400" />
</set>

这是直接从我的头顶（因此未经测试），但应该足以让你朝着正确的方向前进