對於按鈕事件，我應該使用AlertDialog.builder什麼上下文？

Question

我使用此代碼...請糾正它

btnLogin.setOnClickListener(new OnClickListener() 
     { 
     @Override 
     public void onClick(View v) 
     { 
     // Check Login 
     String username = etUsername.getText().toString(); 
     String password = etPassword.getText().toString(); 

      String str1 = DownloadText("http://........"); 
      if(str1.length()==1) 
      { 

      AlertDialog dialog = new AlertDialog.Builder(btnLogin).setTitle("Alert 1").setMessage("Login Success").create(); 
      alertDialog.setButton("OK", new DialogInterface.OnClickListener() { 
          public void onClick(DialogInterface dialog, int which) { 
            return; 
          }}); 
}} 

Answer 1

....新AlertDialog.Builder（YourActivity.this）......