java - 在“saved.add(FileName); add 时出现错误如何解决这个错误？

Question

我一直在尝试构建一个获取文件名然后将其输入 a 的页面，listview然后首先出现此问题我不知道如何构建布局页面，然后Saved.add(FileName);在添加时此行特别?

我尝试删除最终的 infront 列表视图，但最终在 Saved 上出现错误

这是有问题的代码：

public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    final ImageButton Add = (ImageButton)findViewById(R.id.imageButton);
      final ListView Saved = (ListView)findViewById(R.id.Saved_list);
     final ArrayAdapter<String> Arr1 = new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_1);
    Saved.setAdapter(Arr1);

    Add.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            AlertDialog.Builder builder=new AlertDialog.Builder(MainActivity.this);
            builder.setTitle("Save");

            View mView = getLayoutInflater().inflate(R.layout.SaveFile_dialog_layout, null);
            final EditText  SavedText = (EditText) findViewById(R.id.SavedText);
            Button Save = (Button)mView.findViewById(R.id.Save);
            Button Later = (Button)mView.findViewById(R.id.Later);
            Button Cancel = (Button)mView.findViewById(R.id.Cancel);


            builder.setView(mView);
            final AlertDialog SavingsDialogue =builder.create();

            Save.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if (!SavedText.getText().toString().isEmpty()){
                      String  FileName = SavedText.getText().toString();
                      Saved.add(FileName);
                     SavedText.getText().clear();
                     Toast.makeText(MainActivity.this,"file name added",Toast.LENGTH_LONG).show();
                     Intent Transition = new Intent(MainActivity.this,Main2Activity.class);
                        startActivity(Transition);
                        // Here I need to add the file organizayion system to start adding the file

                    }