ch12.rar

package com.ehappy.exlogin; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.Manifest; import android.app.AlertDialog; import android.content.DialogInterface; import android.content.pm.PackageManager; import android.os.Build; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.InputStreamReader; public class MainActivity extends AppCompatActivity { private EditText edtID, edtPW; private Button btnOK, btnReset; private String[] login; private File filename; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); edtID = (EditText)findViewById(R.id.edtID); edtPW = (EditText)findViewById(R.id.edtPW); btnOK = (Button)findViewById(R.id.btnOK); btnReset = (Button)findViewById(R.id.btnReset); btnOK.setOnClickListener(listener); btnReset.setOnClickListener(listener); requestStoragePermission(); //檢查驗證 } //檢查驗證 private void requestStoragePermission() { if(Build.VERSION.SDK_INT >= 23) { //Androis 6.0 以上 //判斷是否已取得驗證 int hasPermission = checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE); if(hasPermission != PackageManager.PERMISSION_GRANTED) { //未取得驗證 requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 1); return; } } readFile(); //已取得驗證 } //requestPermissions 觸發的事件 @Override public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { if (requestCode == 1) { if (grantResults[0] == PackageManager.PERMISSION_GRANTED) { //按 允許 鈕 readFile(); } else { Toast.makeText(this, "未取得權限！", Toast.LENGTH_SHORT).show(); finish(); //結束應用程式 } } else { super.onRequestPermissionsResult(requestCode, permissions, grantResults); } } //讀取檔案 private void readFile() { filename = new File("sdcard/login.txt"); //SD卡根目錄密碼檔 try { FileInputStream fin = new FileInputStream(filename); BufferedReader reader = new BufferedReader(new InputStreamReader(fin)); String line = "", wholedata = ""; int i = 0; while ((line = reader.readLine()) != null) { wholedata = wholedata + line + "\n"; i++; } login = wholedata.split("\n"); reader.close(); fin.close(); } catch (Exception e) { Toast.makeText(getApplicationContext(), "error!", Toast.LENGTH_LONG) .show(); e.printStackTrace(); } } private Button.OnClickListener listener=new Button.OnClickListener() { @Override public void onClick(View v) { switch(v.getId()) { case R.id.btnOK: //登入 //檢查帳號及密碼是否都有輸入 if(edtID.getText().toString().equals("") || edtPW.getText().toString().equals("")){ Toast.makeText(getApplicationContext(), "帳號及密碼都必須輸入！", Toast.LENGTH_LONG) .show(); break; } Boolean flag=false; for(int i=0;i<login.length;i+=2){ if(edtID.getText().toString().equals(login[i])){ //帳號存在 flag=true; if(edtPW.getText().toString().equals(login[i+1])){ //密碼正確 new AlertDialog.Builder(MainActivity.this) .setTitle("登入") .setMessage("登入成功！\n歡迎使用本應用程式！") .setPositiveButton("確定", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialoginterface, int i) { //轉換到應用程式啟始頁面程式碼置於此處 finish(); } }) .show(); } else { Toast.makeText(getApplicationContext(), "密碼不正確！", Toast.LENGTH_LONG) .show(); edtPW.setText(""); break; } } } if(!flag) { Toast.makeText(getApplicationContext(), "帳號不正確！", Toast.LENGTH_LONG) .show(); edtID.setText(""); edtPW.setText(""); } break; case R.id.btnReset: //重新輸入 edtID.setText(""); edtPW.setText(""); break; } } }; }