android--data Storage (Classroom code collation: sharedpreferences Storage and mobile internal file storage)

Layout file:

1 <?XML version= "1.0" encoding= "Utf-8"?>2 <LinearLayoutxmlns:android= "Http://schemas.android.com/apk/res/android"3 Xmlns:tools= "Http://schemas.android.com/tools"4 Android:layout_width= "Match_parent"5 Android:layout_height= "Match_parent"6 Android:paddingbottom= "@dimen/activity_vertical_margin"7 Android:paddingleft= "@dimen/activity_horizontal_margin"8 Android:paddingright= "@dimen/activity_horizontal_margin"9 Android:paddingtop= "@dimen/activity_vertical_margin"Ten Tools:context= "Com.hanqi.testapp3.MainActivity" One android:orientation= "vertical"> A  -     <TextView -         Android:layout_width= "Wrap_content" the Android:layout_height= "Wrap_content" - Android:text= "Hello world!" - Android:id= "@+id/tv_1"/> -     <Button +         Android:layout_width= "Match_parent" - Android:layout_height= "Wrap_content" + Android:text= "SP Storage" A Android:onclick= "Bt_onclick"/> at     <Button -         Android:layout_width= "Match_parent" - Android:layout_height= "Wrap_content" - Android:text= "sp read" - Android:onclick= "Bt1_onclick"/> -     <EditText in         Android:layout_width= "Match_parent" - Android:layout_height= "Wrap_content" to Android:hint= "Please enter ..." + Android:id= "@+id/et_1"/> -     <Button the         Android:layout_width= "Match_parent" * Android:layout_height= "Wrap_content" $ Android:text= "Write internal file"Panax Notoginseng Android:onclick= "Bt2_onclick"/> -     <Button the         Android:layout_width= "Match_parent" + Android:layout_height= "Wrap_content" A Android:text= "Read internal file" the Android:onclick= "Bt3_onclick"/> + </LinearLayout>

Java class:

1  Packagecom.hanqi.testapp3;2 3 Importandroid.content.SharedPreferences;4 ImportAndroid.os.Bundle;5 Importandroid.support.v7.app.AppCompatActivity;6 ImportAndroid.view.View;7 ImportAndroid.widget.EditText;8 ImportAndroid.widget.TextView;9 ImportAndroid.widget.Toast;Ten  One ImportJava.io.File; A ImportJava.io.FileInputStream; - ImportJava.io.FileOutputStream; - ImportJava.io.PrintStream; the  -  Public classMainactivityextendsappcompatactivity { -  - EditText et_1; + TextView tv_1; - @Override +     protected voidonCreate (Bundle savedinstancestate) { A         Super. OnCreate (savedinstancestate); at Setcontentview (r.layout.activity_main); -Et_1 =(EditText) Findviewbyid (r.id.et_1); -Tv_1 =(TextView) Findviewbyid (r.id.tv_1); -     } -      Public voidBt_onclick (View v) //sharedpreferences storage  -     { in         //1. Get Sharedpreferences Object -Sharedpreferences sharedpreferences = getsharedpreferences ("abc", mode_append); to         //2. Get the editor +Sharedpreferences.editor Editor =Sharedpreferences.edit (); -         //3. Adding Data Using editor the //editor.putstring ("A", "abcdef"); * //Editor.putlong ("Long", 12345); $Editor.remove ("a");Panax Notoginseng         //4. Submit a Save - editor.commit (); theToast.maketext (mainactivity. This, "Save data successfully", Toast.length_short). Show (); +     } A     //Read the      Public voidBt1_onclick (View v) +     { -Sharedpreferences sp = getsharedpreferences ("abc", mode_private); $String str = sp.getstring ("A", "Default value")); $Toast.maketext (mainactivity. This, "key = a" + "value =" +str, toast.length_short). Show (); -     } -     //Write internal files (phone internal file storage)  the      Public voidBt2_onclick (View v) -     {Wuyi         //write files from memory the         //1. Get the internal storage directory -         Try { WuFile File =Getfilesdir (); -String Path =File.getabsolutepath (); AboutToast.maketext (mainactivity. This, "path =" +path, Toast.length_short). Show (); $             //2. Writing to a file with an output stream -FileOutputStream fos = openfileoutput ("Test.txt", mode_append); -             //3. Writing file Contents -PrintStream PS =NewPrintStream (FOS); A  +String str =Et_1.gettext (). toString (); the  - ps.print (str); $ //ps.print ("test"); the //ps.println ("line wrapping"); the ps.close (); the  the fos.close (); -Toast.maketext (mainactivity. This, "Saved successfully", Toast.length_short). Show (); in         } the         Catch(Exception e) the         { AboutToast.maketext (mainactivity. This, "Save Failed", Toast.length_short). Show (); the         } the  the     } +      Public voidBt3_onclick (View v) -     { the         Try {Bayi             //input Stream theFileInputStream FIS = openfileinput ("Test.txt"); the             //1. Definition byte[] -             byte[] B =New byte[1024]; -             inti = 0;//length of data read theString str1 = ""; the             //2. Cyclic reading the              while((i = Fis.read (b)) >0) the             { -String str =NewString (b,0, i); theSTR1 + =str; the             } the fis.close ();94 Tv_1.settext (str1); the         } the         Catch(Exception e) the         {98  About         } -     }101}

android--data Storage (Classroom code collation: sharedpreferences Storage and mobile internal file storage)