ListView控件显示无数据，同时通过光标填充 [英] LIstView shows no data while populating through cursor
问题描述
我是新的Android开发。我使用的ListView列出从SQLite数据库的一些数据。
我的main.xml文件看起来像：
I am new to Android development. I am using ListView to list some data from SQLite database. my Main.xml file looks like:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/inspections"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<!-- Header -->
<LinearLayout android:id="@+id/header"
android:background="#ff347c12"
android:layout_height="wrap_content"
android:layout_width="fill_parent"
>
<TextView android:id="@+id/item1"
android:layout_height="fill_parent"
android:layout_width="wrap_content"
android:width="100dip"
android:height="30dip"
android:text="Id"
/>
<TextView android:id="@+id/item2"
android:layout_height="fill_parent"
android:layout_width="wrap_content"
android:text="Customer"
android:width="100dip"
android:height="30dip"
/>
<TextView android:id="@+id/item3"
android:layout_height="fill_parent"
android:layout_width="wrap_content"
android:text="Contract"
android:width="100dip"
android:height="30dip"
/>
<TextView android:id="@+id/item4"
android:layout_height="fill_parent"
android:layout_width="wrap_content"
android:text="Inspector"
android:width="100dip"
android:height="30dip"
/>
</LinearLayout>
<!-- List Divider -->
<View android:layout_width="fill_parent"
android:layout_height="1dip"
android:background="?android:attr/listDivider" />
<!-- ListView (grid_items) -->
<LinearLayout android:id="@+id/layout"
android:layout_width="wrap_content"
android:layout_height="fill_parent">
<ListView android:id="@+id/listview"
android:layout_height="fill_parent"
android:layout_width="fill_parent">
</ListView>
</LinearLayout>
</LinearLayout>
我使用的是用来存放每行的数据grid_item.xml，它看起来像：
I am using grid_item.xml which is used to hold data of each row, it looks like:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView android:id="@+id/item1"
android:text="row_id"
android:layout_height="fill_parent"
android:layout_width="wrap_content"
android:width="20dip"
/>
<TextView android:id="@+id/item2"
android:text="col_1"
android:layout_height="fill_parent"
android:layout_width="wrap_content"
android:width="100dip"
/>
<TextView android:id="@+id/item3"
android:text="col_2"
android:layout_height="fill_parent"
android:layout_width="wrap_content"
android:width="100dip"
/>
<TextView android:id="@+id/item4"
android:text="col_3"
android:layout_height="fill_parent"
android:layout_width="wrap_content"
android:width="100dip"
/> </LinearLayout>
code：
public class Inspections extends Activity{
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
try
{
super.onCreate(savedInstanceState);
setContentView(R.layout.inspections);
LoadInspections();
}
catch (Exception e) {
CommonMethods.ShowMessageBox(this, e.toString());
}
}
private void LoadInspections()
{
try
{
DBAdapter db = new DBAdapter(this);
db.open();
Cursor cur = db.GetInspections();
if(cur.moveToFirst())
{
startManagingCursor(cur);
ListView lv = (ListView)findViewById(R.id.listview);
// create the grid item mapping
String[] from = new String[] {"_id", "customer", "contract", "inspector"};
int[] to = new int[] {R.id.item1, R.id.item2, R.id.item3, R.id.item4 };
// fill in the grid_item layout
SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.grid_item, cur, from, to);
lv.setAdapter(adapter);
Log.d("Inspection", "Records found " + cur.getString(1) + "/ "+ cur.getString(2)+ "/ "+ cur.getString(3));
}
else
{
Log.d("Inspection", "No reords");
}
db.close();
}
catch(Exception ex)
{
Log.d("Inspection", "Error: "+ ex.toString());
}
}
}
问题：
也有一些是错误的LoadInspections（），列表视图不显示数据，但只有标题-ROW。光标检索数据，检查该行：
Problem: There is something wrong with LoadInspections(), the list-view show no data but only the HEADER-ROW. The cursor is retrieving data, check this line:
Log.d("Inspection", "Records found " + cur.getString(1) + "/ "+ cur.getString(2)+ "/ "+ cur.getString(3));
日志窗口显示数据。
The log window is displaying the data.
我尽我所能找到计算器答案，但未能成功。
预先感谢您的宝贵时间和放大器;帮帮我。
I tried my best to find the answer on stackoverflow but could not succeeded. Thanks in advance for your valuable time & help.
推荐答案
我尝试不同的东西和放大器; 当我去掉了头和安培;从我的main.xml列表分隔部分，它的工作。很奇怪？
I was trying different things & when i removed the "Header" & "List Divider" sections from my main.xml it worked. Very Strange??
所以，我的main.xml现在看起来像：
So my main.xml now looks like:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/inspections"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<!-- ListView (grid_items) -->
<LinearLayout android:id="@+id/layout"
android:layout_width="wrap_content"
android:layout_height="fill_parent">
<ListView android:id="@+id/mylistview"
android:layout_height="fill_parent"
android:layout_width="fill_parent">
</ListView>
</LinearLayout>
</LinearLayout>
在列表视图的这种奇怪的行为可有人对此有何评论？
Can somebody comment on this strange behavior of listview?
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