将asynctask值传递给mainactivity时出现上下文错误

Question

在我的主要活动中，如果我应用此代码，我收到错误gridviewadapter() cannot be applied,这是上下文中的问题。

  GridViewAdapter adapter = new GridViewAdapter(this, R.layout.grid_item_layout, result);

如果我这样申请：

public MainActivity (Context context) {
        mContext = context;

    }
      GridViewAdapter adapter = new GridViewAdapter(mContext, R.layout.grid_item_layout, result);

我在logcat中遇到了这个错误

java.lang.InstantiationException: can't instantiate class com.justedhak.www.i.MainActivity; no empty constructor

我试图将asynctask arraylist值传递给mainactivity ..如何解决？

Answer 1

试

GridViewAdapter adapter = new GridViewAdapter(MainActivity.this, R.layout.grid_item_layout, result);

Answer 2

删除此构造函数

public MainActivity (Context context) {
    mContext = context;
}

在onCreate()

的MainActivity内添加此内容

mContext = this;

Answer 3

GridViewAdapter adapter = new GridViewAdapter（this，R.layout.grid_item_layout，Listitem）;

Answer 4

如果要传递mContext变量，请按以下方式初始化此变量：

public class MainActivity extends AppCompatActivity {
     private final Context mContext = this;

     ... // other codes such as onCreate...
}

希望这有帮助！

Answer 5

不应该为MainActivity类使用构造函数。 请使用：

GridViewAdapter adapter = new GridViewAdapter(getApplicationContext(), R.layout.grid_item_layout, result);

而不是：

GridViewAdapter adapter = new GridViewAdapter(this, R.layout.grid_item_layout, result);