android java从内部类访问，需要声明最终[重复]

Question

        TextView countTV = mView.findViewById(R.id.main_left_count);
        final TextView totalTV = mView.findViewById(R.id.main_left_total);
        orderGoodsAdapter = new OrderGoodsAdapter(mContext,mView){
            @Override
            public void onRefreshBottom(int len,int total) {
                super.onRefreshBottom(len,total);
                countTV.setText(String.valueOf(len));
                totalTV.setText(String.valueOf(total));
            }
        };

此代码将显示错误“android java访问来自内部类，需要声明为final”

如果您将变量设置为最终变量，或将变量设置为类字段，则错误将消失。

类字段和final关键字有什么不同？

Answer 1

您应该这样编码：

public class TestActivity extends Activity {

    private OrderGoodsAdapter orderGoodsAdapter;

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

        final TextView countTV = findViewById(R.id.main_left_count);
        final TextView totalTV = findViewById(R.id.main_left_total);
        orderGoodsAdapter = new OrderGoodsAdapter(TestActivity.this, mView){
            @Override
            public void onRefreshBottom(int len,int total) {
                super.onRefreshBottom(len,total);
                countTV.setText(String.valueOf(len));
                totalTV.setText(String.valueOf(total));
            }
        };
    }
}

或者你应该这样做

public class TestActivity extends Activity {

    private OrderGoodsAdapter orderGoodsAdapter;
    private TextView countTV;
    private TextView totalTV;

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

        countTV = findViewById(R.id.main_left_count);
        totalTV = findViewById(R.id.main_left_total);
        orderGoodsAdapter = new OrderGoodsAdapter(TestActivity.this, mView){
            @Override
            public void onRefreshBottom(int len,int total) {
                super.onRefreshBottom(len,total);
                countTV.setText(String.valueOf(len));
                totalTV.setText(String.valueOf(total));
            }
        };
    }
}

您可以检查此以获取更多解释：SO链接