无法在以下代码中解析Preferences.readString方法：

Question

package com.jiit.minorproject.emergencycontact;

    import android.net.Uri;
    import android.os.Bundle;
    import android.app.Activity;
    import android.content.ActivityNotFoundException;
    import android.content.Intent;
    import android.util.Log;
    import android.view.Menu;
    import android.view.View;

    import java.util.prefs.Preferences;

公共类MainActivity扩展了Activity {

/*
 * HOSPITAL, POLICE, FIRESTATION, and AMBULANCE are constant variables that are assigned
 * to their respective emergency itent. It helps us to draw icons and perform web services
 * related activities.
 */
private static final int HOSPITAL = 1;
private static final int POLICE = 2;
private static final int FIRESTATION = 3;
private static final int AMBULANCE = 4;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    if(Preferences.readString(this, Preferences.NAME) == null){
        startActivity(new Intent(this, Registration.class));
        if(Preferences.readString(this, Preferences.NAME) == null){
            this.finish();
        }
    } else {
        setContentView(R.layout.activity_main);
    }
}

无法解析Prefernces.readString方法

Answer 1

java.util.prefs.Preferences通常不会在Android代码中使用。但即使它是 - 该类中没有readString方法。查看其上的文档https://docs.oracle.com/javase/7/docs/api/java/util/prefs/Preferences.html

我不确定为什么你认为这个功能应该存在，但它确实没有。

Answer 2

如何创建活动PREFERENCE Android？

首先创建一个新的XML

然后这个xml说出MainActivity的女儿是怎样的

你看起来像这样

http://www.hermosaprogramacion.com/wp-content/uploads/2015/04/android-studio-settings-preconfigured.png

它是第一个然后玩jeje，reed官方信息。

Android developers：设置