Question

我正在将ListView与自定义适配器一起使用，我想添加全部具有自己的删除按钮的行。我已经设法添加了行，但是当我按下删除按钮时，无论我按下什么删除按钮，它总是删除列表中的最后一个条目。

我注意到我不是第一个出现类似问题的人，但是我无法弄清楚代码中的错误。

这是我的主要活动：

ListView mListView = FindViewById<ListView>(Resource.Id.listView1);

ListViewAdapter myAdapter = new ListViewAdapter(this);

Button btnAdd = FindViewById<Button>(Resource.Id.btnAdd);

btnAdd.Click += (s,e) =>
{
    myAdapter.AddExercise();

    if(mListView.Adapter == null)
    {
        mListView.Adapter = myAdapter;
    }
};

这是我的自定义适配器中的代码：

class ListViewAdapter : BaseAdapter<Exercise>
    {
        private Activity mContext;
        private List<Exercise> mItems = new List<Exercise>();

        public void AddExercise()
        {
            mItems.Add(new Exercise());
            NotifyDataSetChanged();
        }

        public ListViewAdapter (Activity context)
        {
            mContext = context;
        }

        public override Exercise this[int position]

        {
            get { return mItems[position]; }
        } 

        public override int Count 
        {
            get { return mItems.Count; }
        }

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

        public override long GetItemId(int position)
        {
            return position;
        }

        public override View GetView(int position, View convertView, ViewGroup parent)
        {
            MyViewHolder holder = null;
            View row = convertView;

            if (row != null)
            {
                holder = row.Tag as MyViewHolder; 
            }
            if (holder == null)
            {
                row = mContext.LayoutInflater.Inflate(Resource.Layout.row, null);

                holder = new MyViewHolder();

                // setting the spinners

                holder.exercise = row.FindViewById<Spinner>(Resource.Id.spinnerExercise);
                holder.sets = row.FindViewById<Spinner>(Resource.Id.spinnerSets);

                var adapterExercise = ArrayAdapter.CreateFromResource(row.Context, Resource.Array.exercises_array, Android.Resource.Layout.SimpleSpinnerItem);

                adapterExercise.SetDropDownViewResource(Android.Resource.Layout.SimpleSpinnerDropDownItem);
                holder.exercise.Adapter = adapterExercise;

                var adapterSets = ArrayAdapter.CreateFromResource(row.Context, Resource.Array.sets_array, Android.Resource.Layout.SimpleSpinnerItem);

                adapterSets.SetDropDownViewResource(Android.Resource.Layout.SimpleSpinnerDropDownItem);
                holder.sets.Adapter = adapterSets;

                // setting other elements

                holder.reps = row.FindViewById<EditText>(Resource.Id.textReps);
                holder.kgs = row.FindViewById<EditText>(Resource.Id.textKgs);

                // setting button

                holder.removeButton = row.FindViewById<Button>(Resource.Id.remove);

                holder.removeButton.Click += (object sender, EventArgs e) =>
                {
                    int pos = (int)(((Button)sender).GetTag(Resource.Id.remove));
                    mItems.RemoveAt(pos);
                    NotifyDataSetChanged();
                    Toast.MakeText(mContext, "deleted" + pos.ToString(), ToastLength.Long).Show();
                };

                row.Tag = holder;
            }


            holder.removeButton.SetTag(Resource.Id.remove, position);

            return row;
        }


    }

    class MyViewHolder : Java.Lang.Object
    {

        public Spinner exercise { get; set; }
        public Button removeButton { get; set; }
        public Spinner sets { get; set; }
        public EditText reps { get; set; }
        public EditText kgs { get; set; }

    }
}

Answer 1

使用ArrayAdapter中的remove（）方法从列表中删除所需的项目。

    'Insert Row Fields
    With ActiveSheet.PivotTables("Rev by Facility")
        With .PivotFields("Facility")
            .Orientation = xlRowField
            .Position = 1
        End With
    'Insert Column Fields
        With .PivotFields("Revenue")
            .Orientation = xlColumnField
            .Position = 1
        End With
    'Insert Data Field
        With .PivotFields("SubTotal 2")
            .Orientation = xlValuesField
            .Position = 1
            .Function = xlSum
            .Name = "Sum of SubTotal 2"
        End With
    End With

另一种方法是修改ArrayList并在ArrayAdapter上调用notifyDataSetChanged（）。

findElement(By.name("username")).sendKeys(${username}) <- here I want to pass JMeter variable

WDS.sampleResult.sampleStart()

WDS.browser.get('https://www.google.com/')

WDS.browser.findElement(org.openqa.selenium.By.name("q")).
sendKeys(**${here I want to put JMeter variable}**)

WDS.sampleResult.sampleEnd()

Answer 2

根据您的描述，在ListView中添加按钮，现在，您想单击Button从ListView中删除项目，我做一个示例，您可以看一下：

Layout9，显示ListView：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
    android:text="Button"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:minWidth="25px"
    android:minHeight="25px"
    android:id="@+id/button1" />
<ListView
    android:minWidth="25px"
    android:minHeight="25px"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/listView1" />

Layout10，ListView模板：

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
    android:text="Name"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:minWidth="25px"
    android:minHeight="25px"
    android:id="@+id/textView1" />

<TextView
    android:text="Age"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:minWidth="25px"
    android:minHeight="25px"
    android:id="@+id/textView2" />
<Button
    android:text="Delete Button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/button1" />

CustomAdapter:

 public class Customadapter : BaseAdapter<Person>
{

    public Activity activity;
    public ObservableCollection<Person> persons;
    public Customadapter(Activity activity, ObservableCollection<Person>persons):base()
    {
        this.activity = activity;
        this.persons = persons;
    }

    public override Person this[int position]
    {
        get
        {
            return persons[position];
        }
    }

    public override int Count
    {
        get
        {
            return persons.Count();
        }
    }

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

    public override long GetItemId(int position)
    {
        return persons[position].Id;
    }

    public override View GetView(int position, View convertView, ViewGroup parent)
    {
        Person item = persons[position];
        var view = convertView ?? activity.LayoutInflater.Inflate(Resource.Layout.layout10, parent, false);
        var txtName = view.FindViewById<TextView>(Resource.Id.textView1);
        var txtAge =  view.FindViewById<TextView>(Resource.Id.textView2);
        var button = view.FindViewById<Button>(Resource.Id.button1);
        txtName.Text = persons[position].Name;
        txtAge.Text = " " + persons[position].Age;  
        if(!button.HasOnClickListeners)
        {
            button.Click += (object sender, EventArgs e) =>
            {

                int index = (int)(((Button)sender).GetTag(Resource.Id.button1));
                persons.RemoveAt(index);

                NotifyDataSetChanged();


            };
        }


        button.SetTag(Resource.Id.button1,position);


        return view;
    }


}

MainActivity：

 private Button button1;
    ObservableCollection<Person> list;
    private ListView listview;
    private void Button1_Click(object sender, EventArgs e)
    {
        list = new ObservableCollection<Person>();
       for(int i=0;i<20;i++)
        {
            Person p = new Person()
            {
                Name = "cherry" + i,
                Age = 20 + i
            };
            list.Add(p);
        }
        listview = FindViewById<ListView>(Resource.Id.listView1);
        var adapter = new Customadapter(this,list);
        listview.Adapter = adapter;

    }

人员班：

 public class Person
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
    public Button btn { get; set; }
}

最后位置总是从ListView中删除

2 个答案: