更改view当中的内容，比如TextView是我们进行项目开发过程中经常遇到的操作。
如果直接使用setText方法切换文字的话，TextView的内容是立刻改变的，没有一个平滑的效果，没有良好的视觉体验。
而TextSwitcher和ImageSwitcher正是实现了这样的功能。
布局文件如下：
< LinearLayout 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"
android:orientation= "vertical"
android:paddingBottom= "@dimen/activity_vertical_margin"
android:paddingLeft= "@dimen/activity_horizontal_margin"
android:paddingRight= "@dimen/activity_horizontal_margin"
android:paddingTop= "@dimen/activity_vertical_margin"
tools:context= ".MainActivity" >
<TextSwitcher
android:id= "@+id/my_txt_switcher"
android:layout_width= "match_parent"
android:layout_height= "wrap_content" />
<ImageSwitcher
android:id= "@+id/my_img_switcher"
android:layout_width= "match_parent"
android:layout_height= "wrap_content" />
<Button
android:id= "@+id/buttonleft"
android:layout_width= "match_parent"
android:layout_height= "wrap_content"
android:text ="切换1" />
<Button
android:id= "@+id/buttonright"
android:layout_width= "match_parent"
android:layout_height= "wrap_content"
android:text ="切换2" />
</ LinearLayout>两个switcher的view，两个button，我就不多解释了。
代码如下：
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout. activity_main);
//使用android自带的左边滑入，右边滑出的动画
Animation in = AnimationUtils.loadAnimation(MainActivity. this, android.R.anim.slide_in_left );
Animation out = AnimationUtils.loadAnimation(MainActivity. this, android.R.anim.slide_out_right );
final TextSwitcher txt_switcher = (TextSwitcher)findViewById(R.id.my_txt_switcher );
//通过ViewFactory创建用于在TextSwitcher中切换的TextView
txt_switcher.setFactory( new ViewFactory() {
@Override
public View makeView() {
// TODO Auto-generated method stub
TextView txt = new TextView(MainActivity.this );
txt.setGravity(Gravity. CENTER);
return txt;
}
});
//设置进入动画，设置移出动画
txt_switcher.setInAnimation(in);
txt_switcher.setOutAnimation(out);
final ImageSwitcher img_switcher = (ImageSwitcher)findViewById(R.id.my_img_switcher );
img_switcher.setFactory( new ViewFactory() {
@Override
public View makeView() {
// TODO Auto-generated method stub
ImageView img = new ImageView(MainActivity.this );
img.setScaleType(ImageView.ScaleType. FIT_CENTER);
return img;
}
});
img_switcher.setInAnimation(in);
img_switcher.setOutAnimation(out);
findViewById(R.id. buttonleft).setOnClickListener( new OnClickListener() {
@Override
public void onClick(View v) {
txt_switcher.setText( "This is left");
// img_switcher.setImageResource(R.drawable.ic_launcher);
}
});
findViewById(R.id. buttonright).setOnClickListener( new OnClickListener() {
@Override
public void onClick(View v) {
txt_switcher.setText( "This is Right");
// img_switcher.setImageResource(R.drawable.inter_cloud);
}
});
}
@Override
public 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;
}
}
就这么几行代码便改变了文本的内容，又增加了很酷的动画效果。本例中使用了slide_in_left/slide_out_right
也可以使用fade_in/fade_out，当然也可以自定义。