访问匿名内部类中的非最终值答案

【问题标题】：Accessing non-final values inside anonymous inner class访问匿名内部类中的非最终值
【发布时间】：2023-03-13 15:01:01
【问题描述】：

我有这 5 个 Edittext 字段，我想使用一个按钮将这些值写入数据库。对于按钮 Clicklistener，我使用了匿名内部类，但只允许使用最终值，这意味着在写入数据库时我将获得空字段。我如何才能将这些字段作为非最终字段访问？有什么办法吗？

 public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    EditText yardarea = (EditText)view.findViewById(R.id.yardarea);
    String areaofyard = yardarea.getText().toString();
    EditText brick = (EditText)view.findViewById(R.id.brick);
    final String brickused = brick.getText().toString();
    EditText rcc = (EditText)view.findViewById(R.id.rcc);
    final String rccused = rcc.getText().toString();
    EditText overhead = (EditText)view.findViewById(R.id.overhead);
    final String ovhh = overhead.getText().toString();
    EditText underground = (EditText)view.findViewById(R.id.underground);
    final String ung = underground.getText().toString();

    Button button = (Button) view.findViewById(R.id.register);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            DatabaseAccess databaseAccess = DatabaseAccess.getInstance(getActivity().getApplicationContext());
            databaseAccess.open();
            databaseAccess.insertIntoCriteriaTable(areaofyard, brickused, rccused, ovhh, ung );
            databaseAccess.close();
        }
    });
}

【问题讨论】：

你想从edittext获取值吗？
@AbhayBohra 是的。我稍微编辑了代码。请看。
为什么不将字符串和变量声明为全局变量？

标签： java android inner-classes anonymous-inner-class

【解决方案1】：

尝试将 EditText 声明为全局

EditText yardarea , brick , rcc,  overhead , underground;

public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    yardarea = (EditText)view.findViewById(R.id.yardarea);
     brick = (EditText)view.findViewById(R.id.brick);
    rcc = (EditText)view.findViewById(R.id.rcc);
    overhead = (EditText)view.findViewById(R.id.overhead);
    underground = (EditText)view.findViewById(R.id.underground);

    Button button = (Button) view.findViewById(R.id.register);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            String areaofyard = yardarea.getText().toString();
            String brickused = brick.getText().toString();
            String rccused = rcc.getText().toString();
            String ovhh = overhead.getText().toString();
            String ung = underground.getText().toString();

            DatabaseAccess databaseAccess = DatabaseAccess.getInstance(getActivity().getApplicationContext());
            databaseAccess.open();
            databaseAccess.insertIntoCriteriaTable(areaofyard, brickused, rccused, ovhh, ung );
            databaseAccess.close();

        }
    });
}

【讨论】：

【解决方案2】：

public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    final EditText yardarea = (EditText)view.findViewById(R.id.yardarea);
    final EditText brick = (EditText)view.findViewById(R.id.brick);
    final EditText rcc = (EditText)view.findViewById(R.id.rcc);
    final EditText overhead = (EditText)view.findViewById(R.id.overhead);
    final EditText underground = (EditText)view.findViewById(R.id.underground);

    Button button = (Button) view.findViewById(R.id.register);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            String areaofyard = yardarea.getText().toString();
            String brickused = brick.getText().toString();
            String rccused = rcc.getText().toString();
            String ovhh = overhead.getText().toString();
            String ung = underground.getText().toString();

            DatabaseAccess databaseAccess = DatabaseAccess.getInstance(getActivity().getApplicationContext());
            databaseAccess.open();
            databaseAccess.insertIntoCriteriaTable(areaofyard, brickused, rccused, ovhh, ung );
            databaseAccess.close();

        }
    });
}

您可以将 EditText 对象声明为 final，也可以将它们声明为全局变量，并在单击按钮时使用上面发布的相同代码。

【讨论】：

【解决方案3】：

把获取字符串放在 onClickListener 中怎么样？

public void onViewCreated(View view, @Nullable Bundle 保存的实例状态）{ super.onViewCreated(view, savedInstanceState);

    EditText yardarea = (EditText)view.findViewById(R.id.yardarea);





    EditText brick = (EditText)view.findViewById(R.id.brick);



    EditText rcc = (EditText)view.findViewById(R.id.rcc);



    EditText overhead = (EditText)view.findViewById(R.id.overhead);




    EditText underground = (EditText)view.findViewById(R.id.underground);




    Button button = (Button) view.findViewById(R.id.register);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String areaofyard = yardarea.getText().toString();
            String brickused = brick.getText().toString();
            String rccused = rcc.getText().toString();
            String ovhh = overhead.getText().toString();
            String ung = underground.getText().toString();
            DatabaseAccess databaseAccess = DatabaseAccess.getInstance(getActivity().getApplicationContext());
            databaseAccess.open();
            databaseAccess.insertIntoCriteriaTable(areaofyard, brickused, rccused, ovhh, ung );
            databaseAccess.close();

        }
    });



}

【讨论】：

不可能，因为我们无法在该内部类中获得 yardarea 的引用。

【解决方案4】：

 You should get the value from edittext inside onClick 


 final EditText yardarea = (EditText)view.findViewById(R.id.yardarea);
 final EditText brick = (EditText)view.findViewById(R.id.brick);
 final EditText rcc = (EditText)view.findViewById(R.id.rcc);
 final EditText overhead = (EditText)view.findViewById(R.id.overhead);
 final EditText underground = (EditText)view.findViewById(R.id.underground);


 button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
              String brickused = brick.getText().toString();
              String rccused = rcc.getText().toString();
              String ovhh = overhead.getText().toString();
              String areaofyard = yardarea.getText().toString();
              String ung = underground.getText().toString();                  
              // Do your database operation with these value
            }
        });

【讨论】：