UpMarqueeTextView-模仿淘宝客户端向上滚动的广告条

ggkwk 9年前

UpMarqueeTextView一个简单的向上滚动的类似跑马灯效果,项目中用到的时候是接受到推送过来的消息向上滚动一次,没有做动态的gif效果,所以都是一些纯文字的简单记录。
UpMarqueeTextView通过实现TextView使用Animator动画来实现,所以需要满足3.0以下的版本需要使用nineold-androids来实现效果,其实原理什么很简单看看代码就能了解。

public class UpMarqueeTextView extends TextView implements Animator.AnimatorListener {        private static final String TAG = "UpMarqueeTextView";        private static final int ANIMATION_DURATION = 200;      private float height;      private AnimatorSet mAnimatorStartSet;      private AnimatorSet mAnimatorEndSet;      private String mText;        public UpMarqueeTextView(Context context) {          super(context);      }        public UpMarqueeTextView(Context context, AttributeSet attrs) {          super(context, attrs);      }        @Override      protected void onDraw(Canvas canvas) {          super.onDraw(canvas);          Log.w(TAG, "--- onDraw ---");          height = getHeight();// 确保view的高度      }        /**--- 初始化向上脱离屏幕的动画效果 ---*/      private void initStartAnimation() {          ObjectAnimator translate = ObjectAnimator.ofFloat(this, "translationY", 0, -height);          ObjectAnimator alpha = ObjectAnimator.ofFloat(this, "alpha", 1f, 0f);          mAnimatorStartSet = new AnimatorSet();          mAnimatorStartSet.play(translate).with(alpha);          mAnimatorStartSet.setDuration(ANIMATION_DURATION);          mAnimatorStartSet.addListener(this);      }        /**--- 初始化从屏幕下面向上的动画效果 ---*/      private void initEndAnimation() {          ObjectAnimator translate = ObjectAnimator.ofFloat(this, "translationY", height, 0);          ObjectAnimator alpha = ObjectAnimator.ofFloat(this, "alpha", 0f, 1f);          mAnimatorEndSet = new AnimatorSet();          mAnimatorEndSet.play(translate).with(alpha);          mAnimatorEndSet.setDuration(ANIMATION_DURATION);      }        /**--- 设置内容 ---**/      public void setText(String text) {          if (TextUtils.isEmpty(text)) {              Log.e(TAG, "--- 请确保text不为空 ---");              return;          }          mText = text;          if (null == mAnimatorStartSet) {              initStartAnimation();          }          mAnimatorStartSet.start();      }          @Override      public void onAnimationStart(Animator animator) {        }        @Override      public void onAnimationEnd(Animator animator) {          super.setText(mText);          if (null == mAnimatorEndSet) {              initEndAnimation();          }          mAnimatorEndSet.start();      }        @Override      public void onAnimationCancel(Animator animator) {        }        @Override      public void onAnimationRepeat(Animator animator) {        }  }

功能确实很简单,设置下动画代码即可实现了。苍蝇虽小也是肉,项目体验下载地址:
https://github.com/Neacy/UpMarqueerTextView/tree/master