经常上google play下载软件,看到它的伸缩式的软件介绍很感兴趣。功能截图如下:
点击文本会下拉更多详细介绍,实现这一功能很简单,废话不多说,直接上代码
private boolean isExpanded = false;
private int lastHeight = 0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_expand_in_context);
final ViewGroup expandableContainer = (ViewGroup) findViewById(R.id.expandable_container);
findViewById(R.id.expandable_text).setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
if (isExpanded) {
ViewGroup.LayoutParams params = (ViewGroup.LayoutParams) expandableContainer
.getLayoutParams();
params.height = lastHeight;
expandableContainer.setLayoutParams(params);
expandableContainer.invalidate();
} else {
lastHeight = expandableContainer.getHeight();
ViewGroup.LayoutParams params = (ViewGroup.LayoutParams) expandableContainer
.getLayoutParams();
params.height = ViewGroup.LayoutParams.WRAP_CONTENT;
expandableContainer.setLayoutParams(params);
expandableContainer.invalidate();
}
isExpanded = !isExpanded;
}
});
}
布局只需要这样:
<FrameLayout
android:id="@+id/expandable_container"
android:layout_width="wrap_content"
android:layout_height="200dp"
android:layout_below="@+id/above"
android:layout_margin="15dp"
>
<TextView
android:id="@+id/expandable_text"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:ellipsize="end"
android:text="@string/loremipsum"
android:clickable="true"/>
</FrameLayout>
父布局限定了可限示的高度,可以使文本不用一次性全部显示,为屏幕节省空间。等用户点击查时才一次性显示全部给用户,再一次点击则隐藏掉。。原理很简单。