Android 开发笔记___存储方式__共享参数__sharedprefences

Android 的数据存储方式有四种，这次是【共享参数__sharedprefences】

听起来挺别扭的，平时看到的app里面，当用户删除了一些软件以后下次安装，发现原来的设置还在，这种情况就是把一些用户的设置保存在手机里面的一个存储区域，

• 格式是XML
• key__Value
• 不方便保存关系比较复杂的数据

write

 package com.example.alimjan.hello_world;

 /**
  * Created by alimjan on 7/4/2017.
  */

         import android.content.Context;
         import android.content.Intent;
         import android.content.SharedPreferences;
         import android.os.Bundle;
         import android.support.v7.app.AppCompatActivity;
         import android.view.View;
         import android.view.View.OnClickListener;
         import android.widget.AdapterView;
         import android.widget.ArrayAdapter;
         import android.widget.EditText;
         import android.widget.Spinner;
         import android.widget.Toast;
         import android.widget.AdapterView.OnItemSelectedListener;

         import com.example.alimjan.hello_world.Utils.DateUtil;

 public class class_4_1_1 extends AppCompatActivity implements OnClickListener {

     private SharedPreferences mShared;
     private EditText et_name;
     private EditText et_age;
     private EditText et_height;
     private EditText et_weight;
     private boolean bMarried = false;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.code_4_1_1);
         et_name = (EditText) findViewById(R.id.et_name);
         et_age = (EditText) findViewById(R.id.et_age);
         et_height = (EditText) findViewById(R.id.et_height);
         et_weight = (EditText) findViewById(R.id.et_weight);
         findViewById(R.id.btn_save).setOnClickListener(this);

         ArrayAdapter<String> typeAdapter = new ArrayAdapter<String>(this,
                 R.layout.item_select, typeArray);
         typeAdapter.setDropDownViewResource(R.layout.item_dropdown);
         Spinner sp_married = (Spinner) findViewById(R.id.sp_married);
         sp_married.setPrompt("请选择婚姻状况");
         sp_married.setAdapter(typeAdapter);
         sp_married.setSelection(0);
         sp_married.setOnItemSelectedListener(new TypeSelectedListener());

         mShared = getSharedPreferences("share", MODE_PRIVATE);
     }

     private String[] typeArray = {"未婚", "已婚"};
     class TypeSelectedListener implements OnItemSelectedListener {
         public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
             bMarried = (arg2==0)?false:true;
         }

         public void onNothingSelected(AdapterView<?> arg0) {
         }
     }

     @Override
     public void onClick(View v) {
         if (v.getId() == R.id.btn_save) {
             String name = et_name.getText().toString();
             String age = et_age.getText().toString();
             String height = et_height.getText().toString();
             String weight = et_weight.getText().toString();
             if (name==null || name.length()<=0) {
                 showToast("请先填写姓名");
                 return;
             }
             if (age==null || age.length()<=0) {
                 showToast("请先填写年龄");
                 return;
             }
             if (height==null || height.length()<=0) {
                 showToast("请先填写身高");
                 return;
             }
             if (weight==null || weight.length()<=0) {
                 showToast("请先填写体重");
                 return;
             }

             SharedPreferences.Editor editor = mShared.edit();
             editor.putString("name", name);
             editor.putInt("age", Integer.parseInt(age));
             editor.putLong("height", Long.parseLong(height));
             editor.putFloat("weight", Float.parseFloat(weight));
             editor.putBoolean("married", bMarried);
             editor.putString("update_time", DateUtil.getCurDateStr("yyyy-MM-dd HH:mm:ss"));
             editor.commit();
             showToast("数据已写入共享参数");
         }
     }

     private void showToast(String desc) {
         Toast.makeText(this, desc, Toast.LENGTH_SHORT).show();
     }

     public static void startHome(Context mContext) {
         Intent intent = new Intent(mContext, class_4_1_1.class);
         mContext.startActivity(intent);
     }

 }

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:focusable="true"
     android:focusableInTouchMode="true"
     android:orientation="vertical"
     android:padding="10dp" >

     <RelativeLayout
         android:layout_width="match_parent"
         android:layout_height="50dp" >

         <TextView
             android:id="@+id/tv_name"
             android:layout_width="wrap_content"
             android:layout_height="match_parent"
             android:layout_alignParentLeft="true"
             android:gravity="center"
             android:text="姓名："
             android:textColor="@color/black"
             android:textSize="17sp" />

         <EditText
             android:id="@+id/et_name"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:layout_marginBottom="5dp"
             android:layout_marginTop="5dp"
             android:layout_toRightOf="@+id/tv_name"
             android:background="@drawable/editext_selector"
             android:gravity="left|center"
             android:hint="请输入姓名"
             android:inputType="text"
             android:maxLength="12"
             android:textColor="@color/black"
             android:textColorHint="@color/grey"
             android:textCursorDrawable="@drawable/text_cursor"
             android:textSize="17sp" />
     </RelativeLayout>

     <RelativeLayout
         android:layout_width="match_parent"
         android:layout_height="50dp" >

         <TextView
             android:id="@+id/tv_age"
             android:layout_width="wrap_content"
             android:layout_height="match_parent"
             android:layout_alignParentLeft="true"
             android:gravity="center"
             android:text="年龄："
             android:textColor="@color/black"
             android:textSize="17sp" />

         <EditText
             android:id="@+id/et_age"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:layout_marginBottom="5dp"
             android:layout_marginTop="5dp"
             android:layout_toRightOf="@+id/tv_age"
             android:background="@drawable/editext_selector"
             android:gravity="left|center"
             android:hint="请输入年龄"
             android:inputType="number"
             android:maxLength="2"
             android:textColor="@color/black"
             android:textColorHint="@color/grey"
             android:textCursorDrawable="@drawable/text_cursor"
             android:textSize="17sp" />
     </RelativeLayout>

     <RelativeLayout
         android:layout_width="match_parent"
         android:layout_height="50dp" >

         <TextView
             android:id="@+id/tv_height"
             android:layout_width="wrap_content"
             android:layout_height="match_parent"
             android:layout_alignParentLeft="true"
             android:gravity="center"
             android:text="身高："
             android:textColor="@color/black"
             android:textSize="17sp" />

         <EditText
             android:id="@+id/et_height"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:layout_marginBottom="5dp"
             android:layout_marginTop="5dp"
             android:layout_toRightOf="@+id/tv_height"
             android:background="@drawable/editext_selector"
             android:gravity="left|center"
             android:hint="请输入身高"
             android:inputType="number"
             android:maxLength="3"
             android:textColor="@color/black"
             android:textColorHint="@color/grey"
             android:textCursorDrawable="@drawable/text_cursor"
             android:textSize="17sp" />
     </RelativeLayout>

     <RelativeLayout
         android:layout_width="match_parent"
         android:layout_height="50dp" >

         <TextView
             android:id="@+id/tv_weight"
             android:layout_width="wrap_content"
             android:layout_height="match_parent"
             android:layout_alignParentLeft="true"
             android:gravity="center"
             android:text="体重："
             android:textColor="@color/black"
             android:textSize="17sp" />

         <EditText
             android:id="@+id/et_weight"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:layout_marginBottom="5dp"
             android:layout_marginTop="5dp"
             android:layout_toRightOf="@+id/tv_weight"
             android:background="@drawable/editext_selector"
             android:gravity="left|center"
             android:hint="请输入体重"
             android:inputType="numberDecimal"
             android:maxLength="5"
             android:textColor="@color/black"
             android:textColorHint="@color/grey"
             android:textCursorDrawable="@drawable/text_cursor"
             android:textSize="17sp" />
     </RelativeLayout>

     <RelativeLayout
         android:layout_width="match_parent"
         android:layout_height="50dp" >

         <TextView
             android:id="@+id/tv_married"
             android:layout_width="wrap_content"
             android:layout_height="match_parent"
             android:layout_alignParentLeft="true"
             android:gravity="center"
             android:text="婚否："
             android:textColor="@color/black"
             android:textSize="17sp" />

         <Spinner
             android:id="@+id/sp_married"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:layout_toRightOf="@+id/tv_married"
             android:gravity="left|center"
             android:spinnerMode="dialog" />
     </RelativeLayout>

     <Button
         android:id="@+id/btn_save"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:text="保存到共享参数"
         android:textColor="@color/black"
         android:textSize="20sp" />

 </LinearLayout>

read

 package com.example.alimjan.hello_world;

 import java.util.Map;

 /**
  * Created by alimjan on 7/4/2017.
  */

 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
         import android.os.Bundle;
         import android.support.v7.app.AppCompatActivity;
         import android.widget.TextView;

 public class class_4_1_1_1 extends AppCompatActivity {

     private SharedPreferences mShared;
     private TextView tv_share;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.code_4_1_1_1);
         tv_share = (TextView) findViewById(R.id.tv_share);
         readSharedPreferences();
     }

     private void readSharedPreferences() {
         mShared = getSharedPreferences("share", MODE_PRIVATE);
         String desc = "共享参数中保存的信息如下：";
         Map<String, Object> mapParam = (Map<String, Object>) mShared.getAll();
         for (Map.Entry<String, Object> item_map : mapParam.entrySet()) {
             String key = item_map.getKey();
             Object value = item_map.getValue();
             if (value instanceof String) {
                 desc = String.format("%s\n　%s的取值为%s", desc, key,
                         mShared.getString(key, ""));
             } else if (value instanceof Integer) {
                 desc = String.format("%s\n　%s的取值为%d", desc, key,
                         mShared.getInt(key, 0));
             } else if (value instanceof Float) {
                 desc = String.format("%s\n　%s的取值为%f", desc, key,
                         mShared.getFloat(key, 0.0f));
             } else if (value instanceof Boolean) {
                 desc = String.format("%s\n　%s的取值为%b", desc, key,
                         mShared.getBoolean(key, false));
             } else if (value instanceof Long) {
                 desc = String.format("%s\n　%s的取值为%d", desc, key,
                         mShared.getLong(key, 0l));
             } else {
                 desc = String.format("%s\n参数%s的取值为未知类型", desc, key);
             }
         }
         if (mapParam==null || mapParam.size()<=0) {
             desc = "共享参数中保存的信息为空";
         }
         tv_share.setText(desc);
     }

     public static void startHome(Context mContext) {
         Intent intent = new Intent(mContext, class_4_1_1_1.class);
         mContext.startActivity(intent);
     }

 }

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:focusable="true"
     android:focusableInTouchMode="true"
     android:orientation="vertical"
     android:padding="10dp" >

     <TextView
         android:id="@+id/tv_share"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:textColor="@color/black"
         android:textSize="17sp" />

 </LinearLayout>