ANDROID：适配器位置返回零，并将视图重新添加到ListView

Question

My app requires the ability to add several views on one line in a user selected order.

I found this tutorial which seems to accomplish what I want with a bit of modification.

http://www.androidpeople.com/android-custom-listview-tutorial-example/

Having followed the tutorial and made the required changes, the code works except for one strange issue. The position increments but when it hits ~9 it returns to zero and then re-adds views that are already in the list and thus never reaches the >9 ones.

Also, if I scroll down to the bottom and then back up the very first entry has changed! It may change more but I haven't checked that.

Through some tests I have discovered that the textSize has some effect. If I set it small enough so that all 'rows' will show on screen at once then they appear fine.

This is my listview layout that gets inflated into the main layout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:minHeight="60dip"
  style="@style/DefaultTheme">
    <TextView 
      android:id="@+id/Line01"
      android:layout_width="5dip"
      android:layout_height="fill_parent"
      android:background="#F00" />
    <TextView
      android:id="@+id/Line02"
      android:layout_width="5dip"
      android:layout_height="fill_parent"
      android:background="#0F0" />
    <TextView
      android:id="@+id/Line03"
      android:layout_width="5dip"
      android:layout_height="fill_parent"
      android:background="#00F"
      android:layout_marginRight="5dip"/>
    <LinearLayout
      android:id="@+id/LinearLayout"
      android:layout_weight="1"
      android:layout_width="wrap_content"
      android:layout_height="fill_parent"
      android:orientation="vertical"
      android:padding="2dip">
        <TextView android:id="@+id/Name"
          android:text="Name"
          style="@style/Name" />
        <TextView 
          android:id="@+id/Status"
          android:text="Status"
          style="@style/Status" />
    </LinearLayout>
    <ImageView 
      android:id="@+id/StatusImage"
      style="@style/StatusImage" />
</LinearLayout>

I change background colours and text but that is all. Any ideas what is the problem?

Thanks!

Answer 1

That's because ListView recycles Views. It creates as many Views as required then the one which isn't available will be recycled as next.

So you have to set the colors/attributes in the getView or bindView methods of the adapter.

And btw. what you posted doesn't inflate the ListView, as there is no `' object in it. At best it could be a single ListView item, but not the listview itself ^^

Answer 2

I feel dumb for asking this now and not going back over the tutorial completely.

I was setting the values in my layout I place in the ListView on my main layout only when a new ViewHolder was created. Thus when I scrolled, the views were recycled, but never updated with the correct View settings.

All working fine now!

Cheers