进入App后，想做一个画面的淡出效果，如图所示：
代码非常简单
1 MainActivity.java
package com.example.testanimation;import android.app.Activity;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.view.animation.AlphaAnimation;import android.widget.ImageView;public class MainActivity extends Activity {private ImageView show;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);show = (ImageView)findViewById(R.id.gradually);AlphaAnimation alpha = new AlphaAnimation(1.0f, 0.0f);alpha.setDuration(4000);alpha.setFillAfter(true);show.setAnimation(alpha);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}@Overridepublic boolean onOptionsItemSelected(MenuItem item) {// Handle action bar item clicks here. The action bar will// automatically handle clicks on the Home/Up button, so long// as you specify a parent activity in AndroidManifest.xml.int id = item.getItemId();if (id == R.id.action_settings) {return true;}return super.onOptionsItemSelected(item);}}
代码非常简单
2 main_activity.xml
<RelativeLayout xmlns:android="/apk/res/android"xmlns:tools="/tools"android:layout_width="match_parent"android:layout_height="match_parent"><TextView android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="你好"android:layout_centerInParent="true"android:textSize="30sp"></TextView><ImageViewandroid:id="@+id/gradually"android:layout_height="fill_parent"android:layout_width="fill_parent" android:background="@drawable/senery"/></RelativeLayout>
这个布局文件一定切记，要把ImageView组件写在TextView组件的下方，这样ImageView组件才能完全覆盖TextView组件，如果写到TextView组件之上的话，就没办法覆盖了，这点要记住，代码相对比较简单，没什么可以讲的。
源代码地址：/detail/danielntz/9468570
