錯誤：（42，17）錯誤：無法找到符號變量

我有一個像下面這樣的活動。在這個活動中，我有10個圖像。圖像隨着next和prev按鈕而改變。但我得到這樣的錯誤錯誤：（42，17）錯誤：無法找到符號變量ImageViewPic。請幫助我編寫代碼或編輯我的代碼。錯誤：（42，17）錯誤：無法找到符號變量

這裏是Java代碼

public class MainActivity extends AppCompatActivity { 
     private ImageView img; 
     private Button lbutton, rbutton; 
     private int cur=0; 
     final int [] images = {R.drawable.p1,R.drawable.p2,R.drawable.p3,R.drawable.p4,R.drawable.p5,R.drawable.p6,R.drawable.p7,R.drawable.p8,R.drawable.p9,R.drawable.p10}; 
     private View.OnClickListener lbuttonChangeImageListener,rbuttonChangeImageListener; 

     @Override 
     protected void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.activity_main); 

      img = (ImageView) findViewById(R.id.ImageViewPic); 
      lbutton = (Button) findViewById(R.id.Pbutton); 
      rbutton = (Button) findViewById(R.id.Nbutton); 

      //View.OnClickListener lbuttonChangeImageListener = null; 

      lbutton.setOnClickListener(lbuttonChangeImageListener); 
      //View.OnClickListener rbuttonChangeImageListener = null; 
      rbutton.setOnClickListener(rbuttonChangeImageListener); 

      View.OnClickListener iButtonChangeImageListener = new View.OnClickListener() { 
       public void onClick(View v) { 
        //Increase Counter to move to next Image 
        cur++; 
        cur = cur % images.length; 
        ImageViewPic.setImageResource(images[cur]); 
       } 
      }; 
      View.OnClickListener rbuttonChangeImageListener = new View.OnClickListener() { 
       public void onClick(View v) { 
        //Increase Counter to move to next Image 
        cur--; 
        cur = (cur + images.length) % images.length; 
        ImageViewPic.setImageResource(images[cur]); 
       } 
      };

和XML

?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:gravity="fill" 
    android:orientation="vertical" 
    > 
    <ImageView 
     android:id="@+id/ImageViewPic" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:layout_weight="100" 
     android:adjustViewBounds="true" 
     android:background="#66FFFA" 

     /> 
    <LinearLayout 

     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:background="#33FFFA" 
     > 
     <Button 
      android:id="@+id/Pbutton" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="0" 
      android:text="Prev" 
      android:background="#AA348C90" 
      > 
     </Button> 
     <Button 
      android:id="@+id/Nbutton" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="0" 
      android:text="nxt" 
      android:background="#AA348C90" 
      > 

     </Button> 

    </LinearLayout 
     > 
</LinearLayout>

來源

2015-12-16 Israt

請發佈你的錯誤logcat？ – pRaNaY

嘗試把img.setImageResource(images[cur]);

，而不是ImageViewPic.setImageResource(images[cur]);

來源

2015-12-16 04:00:13

謝謝你的工作。但現在又出現了另一個問題。我不能通過按鈕點擊看到任何圖像。在這方面，我可以說按鈕不工作，但爲什麼？ – Israt

如果這沒有奏效，那就不要試試這個方法。嘗試使其匿名或嘗試將onClick屬性設置爲XML按鈕。 –

我不清楚。你能解釋一下你的答案嗎？ – Israt

試着改變你的代碼，如下所示：

public class MainActivity extends AppCompatActivity { 
    private ImageView img; 
    private Button lbutton, rbutton; 
    private int cur=0; 
    final int [] images = {R.drawable.p1,R.drawable.p2,R.drawable.p3,R.drawable.p4,R.drawable.p5,R.drawable.p6,R.drawable.p7,R.drawable.p8,R.drawable.p9,R.drawable.p10}; 
    private View.OnClickListener lbuttonChangeImageListener,rbuttonChangeImageListener; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     img = (ImageView) findViewById(R.id.ImageViewPic); 
     lbutton = (Button) findViewById(R.id.Pbutton); 
     rbutton = (Button) findViewById(R.id.Nbutton); 

     //View.OnClickListener lbuttonChangeImageListener = null; 

     lbutton.setOnClickListener(lbuttonChangeImageListener); 
     //View.OnClickListener rbuttonChangeImageListener = null; 
     rbutton.setOnClickListener(rbuttonChangeImageListener); 

     View.OnClickListener rbuttonChangeImageListener = new View.OnClickListener() { 
      public void onClick(View v) { 
       //Increase Counter to move to next Image 
       cur++; 
       cur = cur % images.length; 
       img.setImageResource(images[cur]); 
      } 
     }; 
     View.OnClickListener lbuttonChangeImageListener = new View.OnClickListener() { 
      public void onClick(View v) { 
       //Decrease Counter to move to Previous Image 
       cur--; 
       cur = (cur + images.length) % images.length; 
       img.setImageResource(images[cur]); 
      } 
     };

來源

2015-12-16 04:27:09 pRaNaY

錯誤：（42，17）錯誤：無法找到符號變量

回答

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