Android：爲什麼我的字符串變量在我的try-catch塊之外無法識別？

Question

當我打印getCategory在logcat中與下面的代碼我得到the category is Plumber（或任何review.setCategory設爲。）

//post the review that has been clicked in the ListView and send it to 
     // ContactView.php and from that get other review details 
     StringRequest stringRequest = new StringRequest(Request.Method.POST, ContactView_URL, 
       new Response.Listener<String>() { 
        @Override 
        public void onResponse(String response) { 
         //hide the 'loading' box when the page loads 
         pDialog.dismiss(); 
         //toast the response of ContactView.php, which has been converted to a 
         //JSON array in the Php file with JSON encode 
         Toast.makeText(ContactView.this, response, Toast.LENGTH_LONG).show(); 
         for (int i = 0; i < response.length(); i++) { 
          getCategory = null; 
          try { 
           JSONArray responseObject = new JSONArray(response); 
           JSONObject obj = responseObject.getJSONObject(i); 
           Review review = new Review(); 
           review.setCategory(obj.getString("category")); 
           review.setName(obj.getString("name")); 
           review.setPhone(obj.getString("phone")); 
           review.setAddress(obj.getString("address")); 
           review.setComment(obj.getString("comment")); 
           //we are getting the review id so we can pull extra needed info, like Address etc 
           //review.setReviewid(obj.getString("reviewid")); 
           Toast.makeText(ContactView.this, review.getCategory(), Toast.LENGTH_SHORT).show(); 
           //reviewList.add(review); 

           getCategory = review.getCategory(); 
           System.out.println("the category is " + getCategory); 
          } catch (JSONException e) { 
           Log.e("MYAPP", "unexpected JSON exception", e); 
           // Do something to recover ... or kill the app. 
          } 

         } 

但是當我把System.out.println("the category is " + getCategory);其他地方的活動中，try-catch外面，我得到the category is null

我在Stackoverflow上讀了很多帖子，通過在try-catch塊之前聲明getCategory = null;來解決這個問題，但t並沒有解決這個問題。任何幫助，將不勝感激。

Answer 1

您需要分配的例子getCategory

類型下面你可以訪問name所設定的try

String name = ""; 

try{ 

    name = "asdasd"; 

}catch (Exception e){ 

} 

System.out.println(name);