警报对话框未在列表活动中显示Android

警报对话框未在列表活动中显示Android,android,Android,我面临一个问题。 我有一个扩展listactivity的类,其代码如下: public class QuestionListActivity extends ListActivity { //Members private ImageButton bntRefresh; private ImageButton bntSettings; private ImageButton bntGetSurveys; /** Called when the activity is first crea

我面临一个问题。 我有一个扩展listactivity的类,其代码如下:

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initialize函数中,您可以看到我有三个ImageButton,并为它们实现了onClicklisteners。 对于设置和刷新按钮,我已经展示了一个祝酒词,它工作正常。
对于“获取”按钮,我显示了一个对话框,它进一步要求用户执行某些操作,但我面临的问题是对话框没有出现,我不知道为什么?

您忘记了,请写一行

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();
}

你忘了写一行

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();
}
呼叫显示方法

@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();
        }
    });
呼叫显示方法

@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();
        }
    });

AlertDialog getSurveyAlert=新建AlertDialog.BuilderQuestionListActivity.this.create; //用这行代替这行


AlertDialog getSurveyAlert=新建AlertDialog.BuilderQuestionListActivity.this.show

AlertDialog getSurveyAlert=新建AlertDialog.BuilderQuestionListActivity.this.create; //用这行代替这行


AlertDialog getSurveyAlert=新建AlertDialog.BuilderQuestionListActivity.this.show

谢谢,我想我现在有点搞砸了。。只是忘了这么简单的事。谢谢,我想我现在有点搞砸了。。只是忘了这么简单的事。谢谢,我想我现在有点搞砸了。。只是忘了这么简单的事。谢谢,我想我现在有点搞砸了。。忘了这么简单的事。