android - 「addurl」ボタンを押すと強制終了エラー

Question

これは、Dialogのコードを使用する私のアクティビティです...ユーザーがボタンを押すと、ユーザーがそのリンクをデータベースに保存するかどうかを尋ねるダイアログが表示される必要があります。

public class Add_ink extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.websearch);

    Button btn = (Button)  findViewById(R.id.add_link);
    btn.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
               showDialog(0);           
        }
    });
    }
    @Override
    protected Dialog onCreateDialog(int id){
         switch (id){
         case 0:
        return new AlertDialog.Builder(this)
         .setIcon(R.drawable.help_ov)
         .setTitle("This is a dialog with simple text")
         .setPositiveButton("OK",new DialogInterface.OnClickListener() {


            public void onClick(DialogInterface dialog, int whichButton) {
                Toast.makeText(getBaseContext(), "OK Clicked", Toast.LENGTH_SHORT).show();              
            }
        })
        .setNegativeButton("Cancel",new DialogInterface.OnClickListener() {


            public void onClick(DialogInterface dialog, int whichButton) {
                Toast.makeText(getBaseContext(), "Cancel Clicked", Toast.LENGTH_SHORT).show();

            }
        })


        .create(); 
         }
        return null;


    }   
}

Answer 1

Hi The Solutions is 


/*Code*/

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.websearch);

Button btn = (Button)  findViewById(R.id.add_link);
btn.setOnClickListener(new View.OnClickListener() {

    public void onClick(View v) {
           showDialog();           
    }
});

public void showDialog()
{
final AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setMessage("Do you really want to finish ?? You haven't selected any security settings option to activate your app.");  

    builder.setCancelable(false)
                .setPositiveButton("Yes",
                        new DialogInterface.OnClickListener() {
                            public void onClick(
                                    @SuppressWarnings("unused") final DialogInterface dialog,
                                    @SuppressWarnings("unused") final int id) {

                     Toast.makeText(getBaseContext(), "OK Clicked", Toast.LENGTH_SHORT).show();         
dialog.cancel();        
                            }
                        })
                .setNegativeButton("No", new DialogInterface.OnClickListener() {
                    public void onClick(final DialogInterface dialog,
                            @SuppressWarnings("unused") final int id) {

Toast.makeText(getBaseContext(), "Cancel Clicked", Toast.LENGTH_SHORT).show();
                        dialog.cancel();

                    }
                });
        final AlertDialog alert = builder.create();
        alert.show();


}