android - 警告对话框不在列表 Activity 中显示 Android

Question

我遇到了一个问题。我有一个扩展 listactivity 的类，它的代码是这样的:

public class QuestionListActivity extends ListActivity
{
//Members

private ImageButton bntRefresh;
private ImageButton bntSettings;
private ImageButton bntGetSurveys;


 /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.surveylist);

    initialize();

    currentSurveys=new SurveyList();
 }

private void initialize()
{
    bntRefresh= (ImageButton) findViewById(R.id.ibtnRefresh);
    bntRefresh.setImageResource(R.drawable.refresh);
    bntRefresh.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
        Toast.makeText(SurveyListActivity.this, "This will refresh the survey list.", Toast.LENGTH_SHORT).show();   
        }
    });



    bntSettings= (ImageButton) findViewById(R.id.ibtnSettings);
    bntSettings.setImageResource(R.drawable.settings);
    bntSettings.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            Toast.makeText(SurveyListActivity.this, "This will open the settings.", Toast.LENGTH_SHORT).show(); 
        }
    });

    bntGetSurveys= (ImageButton) findViewById(R.id.ibtnGetSurveys);
    bntGetSurveys.setImageResource(R.drawable.getsurvey);
    bntGetSurveys.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) 
        {
            AlertDialog getSurveyAlert = new AlertDialog.Builder(QuestionListActivity .this).create();
            getSurveyAlert.setTitle("Enter QR Code");
            getSurveyAlert.setMessage("Choose a source");
            getSurveyAlert.setButton("Camera", new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {

                }
            });
            getSurveyAlert.setButton2("text", new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {

                }
            });
        }
    });
}

    class SurveyAdapter extends ArrayAdapter<Survey>
    {
      //-- code here for adapter
    }
}

在我的初始化函数中，您可以看到我有三个图像按钮，并且我已经为它们实现了 onClicklisteners。对于“设置”和“刷新”按钮，我展示了一个 Toast，它工作正常。对于“获取”按钮，我显示了一个对话框，进一步要求用户执行某些操作，但我面临的问题是该对话框没有出现，我不知道为什么？

Answer 1

你忘了，写行

getSurveyAlert.show();

试试这个，

bntGetSurveys.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) 
        {
            AlertDialog getSurveyAlert = new AlertDialog.Builder(QuestionListActivity .this).create();
            getSurveyAlert.setTitle("Enter QR Code");
            getSurveyAlert.setMessage("Choose a source");
            getSurveyAlert.setButton("Camera", new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {

                }
            });
            getSurveyAlert.setButton2("text", new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {

                }
            });
        getSurveyAlert.create().show();
}