ListView中因layout_height是wrap_content而引发的问题
问题描述：
先是点击画面上的一个按钮，然后出现下方弹窗
图一：点击弹窗内的“show preview”，会出现listview，如图二
图二：listview出现之后，快速点击任意item，按照设计应该是出现图一的画面
但是实际上出现的是图三的画面，
图三：图中出现了和listview大小一样的透明层
这种现象只会在listview初始化的时候并且是快速点击下才会出现，往后怎么点击都不会出现。
现在怀疑这个问题可能是因为ListView中的layout_height是wrap_content而引发的问题，改成具体fill_parem或者是具体的高度就能够解决，但是要怎么证明这个现象是由这个问题导致的呢？
代码如下：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/flipper_setting"
android:layout_width="fill_parent"
android:layout_height="400px"
android:orientation="vertical"
android:gravity="center_vertical"
android:background="@color/gold"
>
<!-- setting category page -->
<LinearLayout
android:id="@+id/layout1"
android:layout_width="fill_parent"
android:layout_height="400px"
android:gravity="top"
android:orientation="vertical">
<!-- Preview Setting -->
<include
android:id="@+id/include_setting_preview"
layout="@layout/list_row_setting_category" />
</LinearLayout>
<!-- detail setting page -->
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="400px"
android:gravity="top"
android:orientation="vertical"
android:id="@+id/layout2">
<TextView
android:id="@+id/text_title_detail"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center_vertical"
android:textSize = "20px"/>
<com.example.viewflippertest.ListViewConfig
android:id="@+id/listview_detail"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@color/white" />
</LinearLayout>
</LinearLayout>
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button = (Button) findViewById(R.id.id_btn) ;
button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Dialog dialog = createOtherSettingDialog(MainActivity.this);
dialog.show();
WindowManager.LayoutParams lp = dialog.getWindow().getAttributes();
lp.width = 600;
lp.height = 500;
dialog.getWindow().setAttributes(lp);
}
});
}
public static AlertDialog createOtherSettingDialog(final Context context) {
//(1)
LayoutInflater inflater = LayoutInflater.from(context);
final View view = inflater.inflate(R.layout.dlg_setting_other, null);
final ListViewConfig listView_detail = (ListViewConfig)view.findViewById(R.id.listview_detail);
final TextView text_detail_title = (TextView)view.findViewById(R.id.text_title_detail);
final LinearLayout layout2 = (LinearLayout) view.findViewById(R.id.layout2);
final LinearLayout layout1 = (LinearLayout) view.findViewById(R.id.layout1);
layout2.setVisibility(View.GONE);
//(2)
/*============ Preview Setting ================*/
final LinearLayout layout_preview = (LinearLayout)view.findViewById(R.id.include_setting_preview);
final ArrayAdapter<String> adapter_preview = new adaper(context, R.layout.list_row_setting_detail, R.id.text_detail);
final TextView text_category_preview = (TextView)layout_preview.findViewById(R.id.text_category);
final TextView text_value_preview = (TextView)layout_preview.findViewById(R.id.text_value);
text_category_preview.setText(context.getString(R.string.txid_scan_b_other_preview_title));
text_value_preview.setText("On");
final List<String> list_preview = new ArrayList<String>();
list_preview.add(0, "On");
list_preview.add(1, "Off");
for(int i=0; i<list_preview.size(); ++i) {
adapter_preview.add(list_preview.get(i));
}
layout_preview.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
System.out.println("========= layout_preview onclick");
text_detail_title.setText(R.string.txid_scan_b_other_preview_title);
listView_detail.setAdapter(adapter_preview);
layout1.setVisibility(View.GONE);
layout2.setVisibility(View.VISIBLE);
}
});
/*===============================================*/
//(3)
listView_detail.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
System.out.println("========= listView_detail onclick");
if(parent.getAdapter().equals(adapter_preview)) {
// Update preview setting
String value = adapter_preview.getItem(position);
TextView text_value = (TextView)layout_preview.findViewById(R.id.text_value);
text_value.setText(value);
} else {
/* should never reach this point */
}
layout1.setVisibility(View.VISIBLE);
layout2.setVisibility(View.GONE);
}
});
//(4)
final AlertDialog.Builder dialog = new AlertDialog.Builder(context);
dialog.setTitle(context.getString(R.string.txid_scan_t_top_other_title));
dialog.setNegativeButton(context.getString(R.string.txid_cmn_b_close), null);
dialog.setView(view);
return dialog.create();
}
private static class adaper extends ArrayAdapter<String>{
public adaper(Context context, int resource, int textViewResourceId) {
super(context, resource, textViewResourceId);
// TODO Auto-generated constructor stub
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
System.out.println("========= position:" + position + ",convertView:" + convertView +",parent:" + parent.getMeasuredHeight() +",parent.getChildCount:" + parent.getChildCount());
return super.getView(position, convertView, parent);
}
}
https://zhidao.baidu.com/question/327225646391445765.html
wrap_content在绘制时会计算item高度，fill_parem自适应充满，由所包含的子view的高度撑起来，这样绘制比较快。list的数据量较大的情况下，用肉眼可以明显看出来fill_parem加载比较迅速。
点击后要通知更新的，adapter.notifyDataSetChanged