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安卓 - 如何在按钮点击时删除自定义列表视图项？

androidandroid-listviewcustom-lists
3
我有一个自定义列表，其中包含两个文本视图和一个删除按钮。当我单击删除按钮时，我想要删除列表项。 我已经尝试了以下答案：delete item from custom listview，Remove selected item from ListView，Remove ListView items in Android，但都没有成功。
这是我的适配器类：
public class SpecialListAdapter extends BaseAdapter
{
Activity context;
List<String> id = new ArrayList<String>();
List<String> name = new ArrayList<String>();
List<String> newid = new ArrayList<String>();
List<String> newname = new ArrayList<String>();

ViewHolder holder;

public SpecialListAdapter(Activity context, List<String> id, List<String> name) {
    super();
    this.context = context;
    this.id = id;
    this.name = name;
}

public int getCount() {
    // TODO Auto-generated method stub
    return id.size();
}

public Object getItem(int position) {
    // TODO Auto-generated method stub
    return null;
}

public long getItemId(int position) {
    // TODO Auto-generated method stub
    return 0;
}

private class ViewHolder {
    TextView txtViewID;
    TextView txtViewName;
    ImageButton btnDelete;

}

public View getView(final int position, View convertView, ViewGroup parent)
{
    // TODO Auto-generated method stub

    LayoutInflater inflater =  context.getLayoutInflater();

    if (convertView == null)
    {
        convertView = inflater.inflate(R.layout.special_list_item, null);
        holder = new ViewHolder();
        holder.txtViewID = (TextView) convertView.findViewById(R.id.specialId);
        holder.txtViewName = (TextView) convertView.findViewById(R.id.specialName);

        holder.txtViewID.setText(id.get(position));
        holder.txtViewName.setText(name.get(position));

        holder.btnDelete = (ImageButton) convertView.findViewById(R.id.bDelete);
        holder.btnDelete.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                id.remove(position);
                name.remove(position);
                notifyDataSetChanged();

            }
        });


        convertView.setTag(holder);
    }
    else
    {
        holder = (ViewHolder) convertView.getTag();
    }



return convertView;
}
}

编辑

错误日志：

12-18 17:39:46.030: D/AndroidRuntime(17893): Shutting down VM
12-18 17:39:46.030: W/dalvikvm(17893): threadid=1: thread exiting with uncaught exception (group=0x40dc3930)
12-18 17:39:46.053: E/AndroidRuntime(17893): FATAL EXCEPTION: main
12-18 17:39:46.053: E/AndroidRuntime(17893): java.lang.UnsupportedOperationException
12-18 17:39:46.053: E/AndroidRuntime(17893):    at java.util.AbstractList.remove(AbstractList.java:638)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at java.util.AbstractList$SimpleListIterator.remove(AbstractList.java:75)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at java.util.AbstractCollection.remove(AbstractCollection.java:229)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at .SpecialListAdapter$1.onClick(SpecialListAdapter.java:83)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at android.view.View.performClick(View.java:4202)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at android.view.View$PerformClick.run(View.java:17340)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at android.os.Handler.handleCallback(Handler.java:725)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at android.os.Handler.dispatchMessage(Handler.java:92)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at android.os.Looper.loop(Looper.java:137)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at android.app.ActivityThread.main(ActivityThread.java:5039)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at java.lang.reflect.Method.invokeNative(Native Method)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at java.lang.reflect.Method.invoke(Method.java:511)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
12-18 17:39:46.053: E/AndroidRuntime(17893):    at dalvik.system.NativeStart.main(Native Method)
你试过我的解决方案了吗？ - Carnal
5个回答
0

你正在从 "name" List 中仅移除，而且你已经完成了

public int getCount() {
// TODO Auto-generated method stub
    return id.size();
}

因此，列表项的计数不会改变。

在 onClick 行添加 id.remove(position);，然后添加 notifyDataSetChanged();

还要将此放置

holder.btnDelete.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            id.remove(position);
            name.remove(position);
            notifyDataSetChanged();

        }
    });

在 if(convertView == null){...} else {...} 之外/下方，并将 ViewHolder 放在方法内的 ViewHolder holder; 上方，位于此 if 之上。

我已经写了id.remove()。只需水平滚动，您就会看到它。将setOnClickListener移动到if(convertView == null){...} else {...}之外会导致在id.remove(position)处出现java.lang.UnsupportedOperationException。 - AhulR
0
假设您在Activity类中有一个字符串数组的全局变量...
List<String> globalIDArray = new List<String>();
List<String> globalNamesArray = new List<String>();

你可以像这样将适配器设置为列表...

myListView.setAdapter(new SpecialListAdapter(getApplicationContext(), globalIDArray, globalNamesArray);

现在在按钮点击时...

button.setOnClickListener(new OnClickListener() {
       @Override
       public void onClick(View v)
       {
              globalIDArray.remove("id to remove");
              globalNamesArray.remove("name to remove");
              // now just invalidate the views and it will do remaining work automatically
              myListView.invalidateViews();
       }
}

编辑：

您可以在适配器的getView函数中实现删除项目的功能。就像这样...

public View getView(final int position, View convertView, ViewGroup parent)
{
    // TODO Auto-generated method stub

    LayoutInflater inflater =  context.getLayoutInflater();

    if (convertView == null)
    {
        convertView = inflater.inflate(R.layout.special_list_item, null);
        holder = new ViewHolder();
        holder.txtViewID = (TextView) convertView.findViewById(R.id.specialId);
        holder.txtViewName = (TextView) convertView.findViewById(R.id.specialName);

        holder.txtViewID.setText(id.get(position));
        holder.txtViewName.setText(name.get(position));

        holder.btnDelete = (ImageButton) convertView.findViewById(R.id.bDelete);

        //
        // Set tag to button so we can use ID and Name values at 'onClick'
        //
        holder.btnDelete.setTag(new ID_Name_Set(id.get(position), name.get(position)));

        holder.btnDelete.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // retrieve tag object and fetch ID and Name from this object

                ID_Name_Set set = (ID_Name_Set)v.getTag();
                id.remove(set.ID);
                name.remove(set.Name);
                notifyDataSetChanged();

            }
        });


        convertView.setTag(holder);
    }
    else
    {
        holder = (ViewHolder) convertView.getTag();
    }
    return convertView;
}

private class ID_Name_Set
{
    public String ID = "";
    public String Name = "";

    public ID_Name_Set(String id, String name)
    {
        this.ID = id;
        this.Name = name;
    }
}

希望这可以帮到你。
:)
我该如何从我的Activity类中访问删除按钮？ - AhulR
仍然在id.remove(set.ID)上给我相同的错误。 - AhulR
0

您应该按照以下方式将项目的位置添加到按钮中，然后在onClick方法中，您还应该从实际列表中将其删除。

holder.btnDelete = (ImageButton) convertView.findViewById(R.id.bDelete);
holder.btnDelete.setTag(position);

在你的onClick方法中，请添加这些新行：

int pos = (Integer)v.getTag();
//remove item from list and notifydatasetChanged
name.remove(pos);
notifyDataSetChanged();

还有一件事是，在“convertview！= null”的情况下，您也应该为视图添加标签。

我希望这能帮助您，因为它帮助我解决了我的问题。

敬礼。

我尝试了你的代码，但它不起作用！当触发"onClick"时，它给我一个java.lang.UnsupportedOperationException错误。 - AhulR
你可以把完整的错误日志写在这里，这样我就可以看一下。 - denizt
0
List<String> id = new ArrayList<String>();
List<String> name = new ArrayList<String>();

应该是

ArrayList<String> id;
ArrayList<String> name;

List 不会被修改，使用 ArrayList

然后在你的构造函数中使用

this.id = new ArrayList<String>(id);
this.name = new ArrayList<String>(name);
0
    if (convertView == null)
    {
    convertView = inflater.inflate(R.layout.special_list_item, null);
    holder = new ViewHolder();



    convertView.setTag(holder);
    }
    else
    {
    holder = (ViewHolder) convertView.getTag();
     }
    holder.txtViewID = (TextView) convertView.findViewById(R.id.specialId);
    holder.txtViewName = (TextView) convertView.findViewById(R.id.specialName);

    holder.txtViewID.setText(id.get(position));
    holder.txtViewName.setText(name.get(position));

    holder.btnDelete = (ImageButton) convertView.findViewById(R.id.bDelete);
    holder.btnDelete.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            id.remove(position);
            name.remove(position);
            notifyDataSetChanged();

        }
    });
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