Android之File及其内部与外部存储

    package com.example.test0508;
    
    import androidx.appcompat.app.AppCompatActivity;
    
    import android.os.Bundle;
    import android.view.View;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.TextView;
    
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.FileOutputStream;
    import java.io.IOException;
    
    public class FileActivity extends AppCompatActivity {
    
    private EditText mEtName;
    private Button mBtnSav