Android 启动程序时动画效果

1、当你打开一个应用程序时，总会看到前面有一个加载动画页面，下面我们就看看怎么来实现 

2、新建一个.xml 文件，添加一个ImageView 组件，该组件用来加载图片

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

 	<ImageView 
 	    android:id="@+id/welcome_img"
 	    android:layout_width="match_parent"
 	    android:layout_height="match_parent"
 	/>

</RelativeLayout>

3、创建一个Activity,用来启动与实现渐变效果

 

 

package com.example.activity;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.Animation.AnimationListener;
import android.widget.ImageView;

public class MainActivity extends Activity {
    private ImageView welcomeImg = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        welcomeImg = (ImageView) this.findViewById(R.id.welcome_img);
        AlphaAnimation anima = new AlphaAnimation(0.3f, 1.0f);
        anima.setDuration(3000);// 设置动画显示时间
        welcomeImg.startAnimation(anima);
        anima.setAnimationListener(new AnimationImpl());

    }

    private class AnimationImpl implements AnimationListener {

        @Override
        public void onAnimationStart(Animation animation) {
            welcomeImg.setBackgroundResource(R.drawable.welcome);
        }

        @Override
        public void onAnimationEnd(Animation animation) {
            skip(); // 动画结束后跳转到别的页面
        }

        @Override
        public void onAnimationRepeat(Animation animation) {

        }

    }

    private void skip() {
        startActivity(new Intent(this, OtherActivity.class));
        finish();
    }
}