java - 试图调用本地数据库变量并且应用程序停止工作

Question

如果我从本地数据库调用变量，我的应用程序将停止工作。我使用了带有字符串的 ALertDialog(让我大声翻译它)，并且尝试从本地数据库调用变量。

public class CameraActivity extends Activity
{
    private BdLocal bdl = new BdLocal(); //DB
    public static final int TAMANHOAREAFUMACA = 100;
    public static final int QUALIDADEJPEG = 100; 

    PreviewCamera mPreview;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        AlertDialog dialog;
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage(getResources().getString(R.string.afericao_instrucao) +
                String.valueOf(bdl.getLauTempo()) + //this variable make my app stop woking
                getResources().getString(R.string.fotos) +
                String.valueOf(bdl.getQntFotos()) + //this variable make my app stop woking
                getResources().getString(R.string.segundos));

        builder.setPositiveButton(android.R.string.ok, null);
        dialog = builder.create();
        dialog.show();

        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.activity_camera);
    }

我已经使用了一些其他代码，但总是让我的应用程序停止工作。

解决方案？

Answer 1

如果没有堆栈跟踪和 BdLocal 代码，调试起来非常困难。但是，您不能在 setContentView 之前添加对话框。考虑将所有代码移至 onResume 方法:

@Override
protected void onCreate(Bundle savedInstanceState) {  
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.activity_camera);
}

@Override
protected void onResume(){
  super.onResume();
  AlertDialog dialog;
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage(getResources().getString(R.string.afericao_instrucao) +
                String.valueOf(bdl.getLauTempo()) + //this variable make my app stop woking
                getResources().getString(R.string.fotos) +
                String.valueOf(bdl.getQntFotos()) + //this variable make my app stop woking
                getResources().getString(R.string.segundos));

        builder.setPositiveButton(android.R.string.ok, null);
        dialog = builder.create();
        dialog.show();
}

如果 Activity 尚未添加到窗口中，您就无法真正创建对话框。