Question

如何动态测量ListView的高度

Answer 1

item.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="
android:layout_width="wrap_content"
android:layout_height="44dp"
android:paddingLeft="10dp"
android:background="@color/white"
android:descendantFocusability="blocksDescendants"
android:paddingBottom="1dp">

android:id="@+id/tv_contact_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_toRightOf="@+id/iv_contact_photo"
android:textColor="@color/black" />
android:id="@+id/iv_contact_photo"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:layout_margin="5dp" />

在使用此listView的布局中设置属性
<ListView
android:id="@+id/lv_addEventContact"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scrollbarSize="0dp"
android:dividerHeight="0dp"
android:visibility="gone"
/>
定义一个函数将dp转换为像素
public int Dp2Px(Context context, float dp) {
final float scale = context.getResources().getDisplayMetrics().density;
return (int) (dp * scale + 0.5f);
}
定义函数动态控制listView的高度
public void setListViewHeightBasedOnChildren(ListView listView) {
//获取listview的适配器
ListAdapter listAdapter = listView.getAdapter();
//item的高度
int itemHeight = 46;
if (listAdapter == null) {
return;
}
int totalHeight = 0;
for (int i = 0; i < listAdapter.getCount(); i++) {
totalHeight += Dp2Px(getApplicationContext(),itemHeight)+listView.getDividerHeight();
}
ViewGroup.LayoutParams params = listView.getLayoutParams();
params.height = totalHeight;
listView.setLayoutParams(params);
}
在每次listView的adapter发生变化后，要调用setListViewHeightBasedOnChildren(listView)更新界面