android 设置动画时间,如何以特定的时间间隔为图片添加动画效果？

问：StacyM

在Android的开发过程中，我用的是Coursera类别，以下是我想要实现的静态效果图：

目前，我采用的代码是：

XML:

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" />

Java:

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);

}

我应该采用什么算法，来完成左、右脚的淡入淡出的“运动”呢？需要设定一种循环运动的定时器吗？