How to add animation to a text view in android

问题

I have a TextView and I'm trying to add a fade in animation to it. My code is returning null and I don't understand why.

Here is my implementation

This is the fade_in.xml

    <alpha
            xmlns:android="http://schemas.android.com/apk/res/android"    android:fillAfter="true"
            android:duration="1000"
            android:fromAlpha="0.0"
            android:interpolator="@android:anim/accelerate_interpolator"
            android:toAlpha="1.0"/>

and here is how im using it in the corresponding activity

    tv= (TextView)findViewById(R.id.textView);
//-- the below line is returning null
            animation = AnimationUtils.loadAnimation(this,R.anim.fade_in);

            animation.setAnimationListener(new Animation.AnimationListener() {
                @Override
                public void onAnimationStart(Animation animation) {
                tv.setVisibility(View.VISIBLE);
                }

                @Override
                public void onAnimationEnd(Animation animation) {
                    Intent it  = new Intent(SplashActivity.this, MainActivity.class);
                    startActivity(it);
                }

                @Override
                public void onAnimationRepeat(Animation animation) {

                }
            });

            tv.startAnimation(animation);

回答1:

Android TextView Annimation example

XML

<?xml version="1.0" encoding="utf-8"?>

<set xmlns:android="http://schemas.android.com/apk/res/android">
<scale
      android:fromXScale="1.0"
      android:fromYScale="1.0"
      android:toXScale="2.0"
      android:toYScale="2.0"
      android:duration="3000"></scale>
</set>

Code

private void RunAnimation() 
{
  Animation a = AnimationUtils.loadAnimation(this, R.anim.scale);
  a.reset();
  TextView tv = (TextView) findViewById(R.id.firstTextView);
  tv.clearAnimation();
  tv.startAnimation(a);
}

For More :

http://chiuki.github.io/advanced-android-textview/#/5

http://www.hascode.com/2010/09/playing-around-with-the-android-animation-framework/

回答2:

Is your textview id correct?? First check if you are getting your textview id correctly in your app

回答3:

You can load animations from AnimationUtils class in Android and set it to a textview in android.

textview.startAnimation(AnimationUtils.loadAnimation(c, android.R.anim.fade_in));

and you can stop animation using,

textview.clearAnimation();

回答4:

You need setAnimation in your TextView

Example:

tv.setAnimation( animation );

回答5:

Use Animator/AnimatorSet Animation is legacy code

来源：https://stackoverflow.com/questions/34089093/how-to-add-animation-to-a-text-view-in-android

标签

android

animation

fadein