更改view當中的內容，比如TextView是我們進行項目開發過程中經常遇到的操作。
如果直接使用setText方法切換文字的話，TextView的內容是立刻改變的，沒有一個平滑的效果，沒有良好的視覺體驗。
而TextSwitcher和ImageSwitcher正是實現了這樣的功能。
佈局文件如下：
< 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 ="切換1" />
<Button
android:id= "@+id/buttonright"
android:layout_width= "match_parent"
android:layout_height= "wrap_content"
android:text ="切換2" />
</ LinearLayout>兩個switcher的view，兩個button，我就不多解釋了。
代碼如下：
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout. activity_main);
//使用android自帶的左邊滑入，右邊滑出的動畫
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 );
//通過ViewFactory創建用於在TextSwitcher中切換的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;
}
});
//設置進入動畫，設置移出動畫
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;
}
}
就這麼幾行代碼便改變了文本的內容，又增加了很酷的動畫效果。本例中使用了slide_in_left/slide_out_right
也可以使用fade_in/fade_out，當然也可以自定義。