Java 根据所选对话框选项填充自定义列表

填充自定义列表时遇到问题。当应用程序处于“创建”状态时，它会使用默认元素正确填充列表。但是，当我转到“设置”对话框时，我有一个无线电组，允许我选择将使用哪个数组填充列表，但我不能从对话框中调用populatelistview自定义类，因为它不允许我使用“this”作为输入，因为它在对话框中，所以它不接受它作为上下文。这是我的populatelistview类：

 class populateListView extends ArrayAdapter <String>
{
    Context context;
    String [] times;
    String [] runtimes;

    populateListView(Context c,String [] tms, String [] rts)
    {
        super(c, R.layout.seizure_list2,R.id.firstLine,tms);
        this.context=c;
        this.runtimes=rts;
        this.times = tms;

    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent)
    {
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View row = inflater.inflate(R.layout.seizure_list2,parent,false);
        TextView runtime_text = (TextView) row.findViewById(R.id.secondLine);
        TextView time_text = (TextView) row.findViewById(R.id.firstLine);

        time_text.setText(times[position]);
        runtime_text.setText(runtimes[position]);
        return row;


    }
}

最后，这是我与广播组的对话：

`公共无效对话框_过滤器（）{

---

`

ArrayAdapter要求第一个输入是

上下文的实例。由于
对话框
不是从
上下文
扩展而来，因此不能使用
此
实例化适配器。但是，您可以调用
getContext（）
，并将其传递给您。
将用于在onclick方法中创建适配器的代码行更改为如下所示

adapter = adapter = new populateListView(YourActivityName.this, all_times_array, all_runtimes_array);

此方法出现nullpointer异常。在OnCreate期间，我使用此方法时完全没有任何问题。当我调用此方法时：populateListView（YourActivityName.this，all_times_数组，all_runtimes_数组）；您是否已将活动名称替换为“YourActivityName”在代码中？是的，我已经意识到问题来自数组，因为它们是空的。在主活动中它们不是空的。我如何才能将值传递到对话框中？在开关情况下为特定选择将数组分配给适配器我找不到此方法，只有getAppliCationContext（）或getBaseContext（）
    final String[] grpname = {"Today", "This Month", "This Year", "All time"};

    AlertDialog.Builder alt_bld = new AlertDialog.Builder(this);
    //alt_bld.setIcon(R.drawable.icon);
    alt_bld.setTitle("See reports from ...");
    alt_bld.setSingleChoiceItems(grpname, -1, new DialogInterface
            .OnClickListener() {
        public void onClick(DialogInterface dialog, int item) {
            time_filter = item;
            System.out.println(time_filter);
            Toast.makeText(getApplicationContext(),
                    grpname[item] + " selected", Toast.LENGTH_SHORT).show();

            switch (time_filter) {


                case 3:
                    //adapter = new populateListView(this, all_times_array, all_runtimes_array);
                    bannertext = "Total seizures:" + " " + total_seizures;
                    banner.setText(bannertext);
                    list.setAdapter(adapter);

                    break;

                case 0:
                    // adapter = new populateListView(this, today_times_array, today_runtimes_array);
                    bannertext = "Today seizures:" + " " + today_seizures;
                    banner.setText(bannertext);
                    list.setAdapter(adapter);
                    break;

                case 1:
                   // adapter = new populateListView(this, month_times_array, month_runtimes_array);
                    bannertext = "Month seizures:" + " " + month_seizures;
                    banner.setText(bannertext);
                    list.setAdapter(adapter);
                    break;
                case 2:
                  //  adapter = new populateListView(this, year_times_array, year_runtimes_array);
                    bannertext = "Year seizures:" + " " + year_seizures;
                    banner.setText(bannertext);
                    list.setAdapter(adapter);
                    break;


            }


            dialog.dismiss();
        }
            }


    );
    AlertDialog alert = alt_bld.create();
    alert.show();

}

adapter = adapter = new populateListView(YourActivityName.this, all_times_array, all_runtimes_array);