最近,在android中用代碼動態改變某種佈局(組件)的高度時,會遇到如題所示的類轉換異常。上網查了一下,如下所示:
These supply parameters to the parent of this view specifying how it should be arranged. There are many subclasses of ViewGroup.LayoutParams, and these correspond to the different subclasses of ViewGroup that are responsible for arranging their children.
So basically, if you are adding a view to another, you MUST set the LayoutParams of the view to the LayoutParams type that the parent uses, or you will get a runtime error.
比如:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="wrap_content" android:layout_height="wrap_content">
<FrameLayout android:id="@+id/FrameLayout01" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout> 若想在代碼中動態改變FrameLayout的大小,應該這樣寫:
FrameLayout frameLayout=(FrameLayout) convertView.findViewById(R.id.FrameLayout01); LinearLayout.LayoutParams ff=new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, height); |