Question

我开发了一个计数器应用程序，当用户在屏幕上点击时，它会递减-1，并且每次打开应用程序时默认计数器号都是100。现在，我放了一个编辑按钮，它应该更改默认计数器号，但只能显示在屏幕上，并且无法用Java代码实现。下面是Java代码和xml。

MainActivity.xml

<RelativeLayout 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="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:padding="5dp"
    android:id="@+id/tap"
    android:background=" #2471a3 ">

    <TextView
        android:id="@+id/tvcounter"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="130dp"
        android:text="100"
        android:textStyle="bold"
        android:gravity="center"
        android:background="@drawable/shape"
        android:textColor="#FFF"
        android:textSize="55sp" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="30dp"
        android:id="@+id/btnedit"
        android:text="Edit"
        android:textColor="#FFF"
        android:layout_marginLeft="135dp"
        android:background=" #154360 "/>

MainActivity.Java

    RelativeLayout tap;
        int counter=100 ;
        TextView tvcounter;
    tvcounter = findViewById(R.id.tvcounter);
            tap = findViewById(R.id.tap);
    tap.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (counter != 0)
                        counter--;
                    tvcounter.setText(Integer.toString(counter));
                    }
                }
            });

layout_dialog.xml

<EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/editnum"
        android:hint="Enter the number"
        android:textColor="#000"
        android:textSize="20sp"
        android:inputType="number"
        android:layout_marginTop="20dp"/>

ExampleDialog.Java

    public class ExampleDialog extends AppCompatDialogFragment {
        private EditText editnum;
        private ExampleDialogListener listener;

        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
            LayoutInflater inflater = getActivity().getLayoutInflater();
            View view = inflater.inflate(R.layout.layout_dialog, null);
            builder.setView(view)
                    .setTitle("Edit")
                    .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {

                        }
                    })
                    .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            String editnumber=editnum.getText().toString();
                            listener.applynum(editnumber);

                        }
                    });
            editnum = view.findViewById(R.id.editnum);
            return builder.create();
        }

        @Override
        public void onAttach(Context context) {
            super.onAttach(context);
            try {
                listener= (ExampleDialogListener) context;
            } catch (ClassCastException e) {
                throw new ClassCastException(context.toString()+ "must implement ExampleDialog Listener");
            }
        }

        public interface ExampleDialogListener {
            void applynum(String editnumber);
        }
    }

    enter code here

编辑计数器编号后如何实现默认的计数器编号

0 个答案: