如何在Android中禁用listView的回收功能

问题描述 投票:0回答:1

我对Android中的ListView有疑问。我添加了30个项目的列表,这意味着我需要向下滚动。我使用如下适配器:

    <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#70292929"
        android:layout_gravity="top|right"
        android:orientation="horizontal">

      <TableLayout
          android:id="@+id/tablelayout1"
          android:layout_gravity="center_horizontal"
          android:layout_weight="1"
          android:layout_width="match_parent"
          android:layout_height="wrap_content">
        <TableRow android:gravity="left">

          <ListView
              android:id="@+id/listview1"
              android:background="#1b4f72"
              android:layout_weight="0.5"
              android:layout_gravity="top|left"
              android:layout_width="10px"
              android:layout_height="match_parent">
          </ListView>

        </TableRow>
        </TableLayout>
    </LinearLayout> 



            protected override void OnCreate(Bundle savedInstanceState)
            {
                base.OnCreate(savedInstanceState);
                this.RequestWindowFeature(Android.Views.WindowFeatures.NoTitle);
                SetContentView(Resource.Layout.Main);
                LayoutInflater.Inflate(Resource.Layout.MENU, null);
                Android.Views.View globalMENUVIEW = LayoutInflater.Inflate(Resource.Layout.MENU, null); //Listview layout

                AlertDialog globalBUILDER = new AlertDialog.Builder(this).Create();
                globalBUILDER.Window.SetBackgroundDrawableResource(Resource.Drawable.transparant);
                globalBUILDER.Window.SetGravity(Android.Views.GravityFlags.Top | Android.Views.GravityFlags.Right);
                globalBUILDER.SetView(globalMENUVIEW);
                globalBUILDER.SetCanceledOnTouchOutside(true);
                globalBUILDER.Window.SetLayout(800, 500);
                globalBUILDER.Show();

                globalLISTVIEW1 = globalMENUVIEW.FindViewById<ListView>(Resource.Id.listview1);



                List<String> mainMENU = new List<String>();
                for (int i = 0; i < 30; i++)
                {
                    mainMENU.Add("hello" + i);
                }
                globalLISTVIEW1.Adapter = new ArrayAdapter<string>(this, Android.Resource.Layout.SimpleListItem1, mainMENU.ToArray());

//Set item 5 as orange background
                for (int i = 0; i < globalLISTVIEW1.ChildCount; i++)
                {
                    if (i == 5) { globalLISTVIEW1.GetChildAt(i).SetBackgroundColor(Android.Graphics.Color.Orange); }
                    else { globalLISTVIEW1.GetChildAt(i).SetBackgroundColor(Android.Graphics.Color.Transparent); }
                }
            }

现在我已经在itemindex 0上设置了背景色。但是,当我向下滚动时,另一个项目也具有背景色。

我确信ListView使用回收导致此行为的项目。

现在是我的实际问题。就我而言,我永远不会使用超过30个项目,并且会发红色表示可以通过将以下值添加到适配器来禁用回收。

但是我不知道该如何实际执行以及如何将这段代码准确地放在哪里?

@Override
public long getItemId(int position) {
    return position;
}

@Override
public int getItemViewType(int position) {
    return position;
}
android android-listview android-arrayadapter recycle
1个回答
0
投票

这是我的适配器在代码中的外观。我添加了一个“新项目”,然后选择“适配器”作为产生以下代码的项目。

如所见,我已经为getItemId和getItemViewType设置了替代,这应该防止回收。但是此代码似乎并不完整。

我仍然需要像在原始适配器中那样传递所有这些参数:

globalLISTVIEW1.Adapter = new ArrayAdapter<string>(this, Android.Resource.Layout.SimpleListItem1, mainMENU.ToArray());

那么我们如何完成下面的适配器?

 
    class Adapter1 : BaseAdapter
    {

        Context context;

        public Adapter1(Context context)
        {
            
            this.context = context;
        }


        public override Java.Lang.Object GetItem(int position)
        {
            return position;
        }

        public override long GetItemId(int position)
        {
            return position;
        }
        public override int GetItemViewType(int position)
        {
            return position;
        }
        public override View GetView(int position, View convertView, ViewGroup parent)
        {
            var view = convertView;
            Adapter1ViewHolder holder = null;

            if (view != null)
                holder = view.Tag as Adapter1ViewHolder;

            if (holder == null)
            {
                holder = new Adapter1ViewHolder();
                var inflater = context.GetSystemService(Context.LayoutInflaterService).JavaCast<LayoutInflater>();
                //replace with your item and your holder items
                //comment back in
                //view = inflater.Inflate(Resource.Layout.item, parent, false);
                //holder.Title = view.FindViewById<TextView>(Resource.Id.text);
                view.Tag = holder;
            }


            //fill in your items
            //holder.Title.Text = "new text here";

            return view;
        }

        //Fill in cound here, currently 0
        public override int Count
        {
            get
            {
                return 0;
            }
        }

    }

    class Adapter1ViewHolder : Java.Lang.Object
    {
        //Your adapter views to re-use
        //public TextView Title { get; set; }
    }
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