Android implements transparent animation

public class AlphaAnimationActivity extends AppCompatActivity {
 
 private ImageView mImageView;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  (savedInstanceState);
  setContentView(.activity_frame_animation);
  // Just a normal picture  mImageView = findViewById();
  
  ... These are several buttons Used to start animation
 
  
 }

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:andro>
    <alpha
        android:duration="3000"
        android:fromAlpha="0.0"
        android:toAlpha="1.0">

    </alpha>
</set>

//Tween animation method - xmlpublic void start1() {
 //Load the animation xml Animation lAnimation = (this, );
 //Set and start the startup picture (lAnimation);
 
}

//Tween animation method - javaprivate void start2() {
 //Create transparent animation Animation lAnimation = new AlphaAnimation(0.0f, 1.0f);
 //Set animation time (3000);
 //Set animation (lAnimation);
}

<animator xmlns:andro
    android:valueFrom="0"
    android:valueTo="255"
    android:duration="2000"
    android:valueType="intType"/>

//Attribute animation method - ValueAnimator - xmlpublic void start3() {
 // Load XML animation ValueAnimator animator = (ValueAnimator) (this, .alpha_animator);
 (new () {
  @Override
  public void onAnimationUpdate(ValueAnimator animation) {
   int currentValue = (int) ();
   ("Attribute Animation", "onAnimationUpdate: " + ());
   // Assign the changed value to the object's attribute value, the following will explain in detail   (currentValue);
   //Refresh the view, that is, repaint, thereby achieving animation effect   ();
  }
 });
 // Start the animation ();
}

//Attribute animation method - ValueAnimator - javapublic void start4() {
 // Step 1: Set the initial value & end value of the animation attribute // ofInt() has two functions // 1. Create an animation instance // 2. Smoothly transition multiple Int parameters: 0 and 1 are passed here, indicating that the value is smoothly transitioned from 0 to 255 // If 3 Int parameters a, b, c are passed in, then smoothly transition from a to b, then smoothly transition from b to c, and so on ValueAnimator anim = (0, 255);
 // Set the duration of the animation (500);
 // Set animation delay playback time (500);
 // Set the number of repeated playbacks of animation = number of replays +1 // Number of animation playback times = infinite, animation is repeated infinitely (0);
 // Set the repeating animation mode // (Default): Replay in the positive order // :Reverse playback ();
 

 // Step 2: Manually assign the changed value to the object's attribute value: update the listener through the animation // Set the value update listener // That is: the method will be called once every time the value changes or changes once. (new () {
  @Override
  public void onAnimationUpdate(ValueAnimator animation) {
   
   int currentValue = (Integer) ();
   // Get the changed value   (currentValue);
   // Output the changed value   
   // Step 4: Assign the changed value to the object's attribute value, the following will explain in detail   (currentValue);
   
   // Step 5: Refresh the view, that is, repaint, so as to achieve animation effect   ();
   
  }
 });
 //Step 3 Start the animation ();
 // Start the animation // The ValueAnimator class changes the value first, and then manually assigns the value to the object's properties to realize animation; it is indirectly operates on the object's properties // The ValueAnimator class is essentially an operation mechanism that changes values}

<objectAnimator xmlns:andro
    android:propertyName="alpha"
    android:valueFrom="1"
    android:valueTo="0"
    android:duration="2000"
    android:valueType="floatType"
    >
</objectAnimator>

//Attribute animation method - ObjectAnimator - xmlpublic void start5() {
 // Load XML animation Animator animator = (this, .alpha_object_animator);
 
 // Set an animation object (mImageView);
 
 // Start the animation ();
 
 ("Animation","ObjectAnimator - xml");
 
}

//Attribute animation method - ObjectAnimator - javapublic void start6() {
 ObjectAnimator anim = (mImageView, "alpha", 1f, 0f, 1f);
 // means: // The animation object is mButton // The property of the object used by the animation is transparency alpha // The animation effect is: regular - fully transparent - regular // ofFloat() has two functions (500);
 // Set the duration of the animation 
 (500);
 // Set animation delay playback time 
 (0);
 // Set the number of repeated playbacks of animation = number of replays +1 // Number of animation playback times = infinite, animation is repeated infinitely 
 ();
 // Set the repeating animation mode // (Default): Replay in the positive order // :Reverse playback ();
 
}