如何在设备内存中存储用户名和密码

Question

如何将用户名和密码存储在设备内存中。 即使用户关闭应用程序并返回，他也应该能够验证自己的用户名和密码。 现在我正在Eclipse中进行测试...所以请帮助我提供一些指针/链接，让我能够在Eclipse中进行测试，并最终在移动设备上运行。

- David Prun

Answer 1

我使用SharedPreferences来存储用户名/密码，它是一种更轻量级的存储解决方案，并且对您的应用程序安全。

Android Dev Guide中的Shared Preferences

- mmaitlen

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SharedPreferences 不安全！请查看：https://dev59.com/BWox5IYBdhLWcg3wYzUt - Paul Spiesberger

Answer 2

嘿..我为您制作了一个简单的演示，用于保存用户名和密码..!!! 它存储在设备的内部存储器中， 它创建一个文件并通过/从该文件保存/提取数据.. 代码如下：

import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

public class Login extends Activity {

    LinearLayout lymain;

    EditText user_edit;
    EditText pass_edit;

    TextView user_txt;
    TextView pass_txt;

    CheckBox savepass;

    Button save;

    public static final String PREFS_NAME = "MyPrefsFile";
    private static final String PREF_USERNAME = "username";
    private static final String PREF_PASSWORD = "password";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        lymain = new LinearLayout(getApplicationContext());
        lymain.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT));
        lymain.setPadding(15,15,15,15);
        lymain.setOrientation(1);
        lymain.setGravity(Gravity.CENTER);

        user_edit = new EditText(getApplicationContext());
        user_edit.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT));

        pass_edit = new EditText(getApplicationContext());        
        pass_edit.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT));

        user_txt = new TextView(getApplicationContext());
        user_txt.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT));        
        user_txt.setText("Enter Username");

        pass_txt = new TextView(getApplicationContext());
        pass_txt.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT));
        pass_txt.setText("Enter Password");

        savepass = new CheckBox(getApplicationContext());
        savepass.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,40));
        savepass.setText("Save Username/Password?");

        save = new Button(getApplicationContext());
        save.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));
        save.setText(" SAVE ");

        save.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                String loginName = user_edit.getText().toString();
                String password = pass_edit.getText().toString();

                if(savepass.isChecked()){
                    getSharedPreferences(PREFS_NAME,MODE_PRIVATE)
                        .edit()
                        .putString(PREF_USERNAME, loginName)
                        .putString(PREF_PASSWORD, password)
                        .commit();
                    Toast.makeText(getApplicationContext(),"Saved Successfully",Toast.LENGTH_LONG).show();
                }
            }
        });


        SharedPreferences pref = getSharedPreferences(PREFS_NAME,MODE_PRIVATE);   
        user_edit.setText(pref.getString(PREF_USERNAME, null));
        pass_edit.setText(pref.getString(PREF_PASSWORD, null));


        lymain.addView(user_txt);
        lymain.addView(user_edit);
        lymain.addView(pass_txt);
        lymain.addView(pass_edit);
        lymain.addView(savepass);
        lymain.addView(save);

        setContentView(lymain);       
    }
}

- Nirav Dangi

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出于安全原因，我不建议将密码存储在SharedPreferences中，因为可能会被root的手机读取这些选项。使用AccountManager来保存密码或类似的方法可能会更有用。 - ziniestro