计算Item的高度，重设ListView的高度，使ListView一次性列出所有数据，嵌套顺序ScrollView，LinearLayout，ListView

code

/**
     * 设置ListView的高度
     */
    public static void setListViewHeightBasedOnChildren(ListView lv) {
        ListAdapter listAdapter = lv.getAdapter();
        if (listAdapter == null) {
            // pre-condition
            return;
        }

        int totalHeight = 0;
        for (int i = 0; i < listAdapter.getCount(); i++) {
            View listItem = listAdapter.getView(i, null, lv);
            listItem.measure(0, 0);
            totalHeight += listItem.getMeasuredHeight();
        }
        ViewGroup.LayoutParams params = lv.getLayoutParams();
        params.height = totalHeight + (lv.getDividerHeight() * (listAdapter.getCount() - 1));
        lv.setLayoutParams(params);
    }

 ListView使用的时候一定要嵌套在 LinearLayout 中，因为其他的Layout(如RelativeLayout)没有重写onMeasure()，所以会在onMeasure()时抛出异常，导致重设高度失效。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.jay.myappstudy.SvLvActivity">
    <ScrollView
        android:id="@+id/sv1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fillViewport="true">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">
            <ListView
                android:id="@+id/lv1"
                android:layout_width="match_parent"
                android:layout_height="match_parent" />
        </LinearLayout>
    </ScrollView>
</LinearLayout>

　　page code

mlv1 = findViewById(R.id.lv1);
        ListViewAdapter adapter = new ListViewAdapter(this, mlv1,R.layout.fruit_item, data2);

        mlv1.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {

            }
        });
        mlv1.setAdapter(adapter);
        Utility.setListViewHeightBasedOnChildren(mlv1);