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Acessing file

Cource: Embedded Systems and Realtime

Instructor: Dr. Tran Thi Minh Chau

Student : Nguyen Van Lan

Email: lancan.nguyen@gmail.com

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Out line:

Data Storage & Accessing File

Shared Preferences

Internal Storage

External Storage

SQLite Databases

Custom Format Text ( My Project)

HTML & SpannedDemo

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Data Storage

Trong android, Data clutrvinhiu option khc nhau:Shared Preferences

Dliu l private, didngcp Key-ValueInternal Storage

Ludliu ch private v lu trn cc thitbvt lExternal Storage

Ludliu ch public v lu trn cc thitbvt lngoi nh Sdcard

SQLite Databases

L hnh thcludliu c cu trc v htr truy vntheo cu lnh SQL

Network Storage

JDBC

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Shared Preferences

L hnh thclutrdng

Dliu l kiucbn: booleans, floats, ints, longs, and strings.

Hiuqu trong vic lu thng tin cu hnh, thng tin ktni,ngdng.

C g gingvi Bundles

Bnvnghn Bundles

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Shared Preference API

Tomtitng Shared Preferences

getShared Preferences()

getPreferences()

thao tc:

Gi edit() trvitng SharedPreferences.Editor

Thm gi tr : putBoolean(),putString()

Commit() thchin thao tc

Tham kho thm:http://developer.android.com/reference/android/content/Sh

aredPreferences.html

http://developer.android.com/reference/android/content/SharedPreferences.htmlhttp://developer.android.com/reference/android/content/SharedPreferences.htmlhttp://developer.android.com/reference/android/content/SharedPreferences.htmlhttp://developer.android.com/reference/android/content/SharedPreferences.html

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Internal Storage

File clutrctip trn thitbbnh trong.(InternalStorage)

Ddiu ny l private v chchusqun lca chnh ngdngangchy n, cc ngdng khc khng th truy cp

c To ghi private file trong Internal Storage:

Dng openFileOutput() phngthc ny trvitngFileOutputStream:

Code : FileOutputStream f = openFileOutput( FILENAME,

Context.MODE_PRIVATE);

f.write(string.getBytes()); // ghi file

f.close(); //ng tream li

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Khi c file tbnh trong ta dng phngthcopenFileInput() tomtitng FileInputStream

Sau thao tc vi file bng cc phngthc: read(),close()

FileInputStream.read()

Tip : Nhng file thng xuyn sdng trong qu trnh chyngdng ta cnlu chng cnhtimtni : res/raw

OpenRawResource()

-> Lu cache files:Tngtc cho chng trnh, tuy nhin phithng xuyn dndp file cache tiu khng gian nh trong

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External Storage

Lutr ngoi ( External Storage )

uim:

Khng gian lutrln

D di chuyngia cc thitb :PC, Mobile

D thay thnng cp

Nhcim:

Tnh bomt khng cao : public data

Tc truy cpthp

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Accessing file on External Storage

Trc khi dng External Storages cnphikim tra trng tri thitb

boolean mExternalStorageAvailable = false;

boolean mExternalStorageWriteable = false;

String state = Environment.getExternalStorageState();

if (Environment.MEDIA_MOUNTED.equals(state)) {

// We can read and write the media

mExternalStorageAvailable = mExternalStorageWriteable = true;

} else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {

// We can only read the media

mExternalStorageAvailable = true;

mExternalStorageWriteable = false;} else {

// Something else is wrong. It may be one of many other states, but all we need

// to know is we can neither read nor write

mExternalStorageAvailable = mExternalStorageWriteable = false;

}

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Accessing

Mmt file: getExternalFilesDir() (API >= 8)getExternalStorageDirectory() (API < 7)

Thmcvitdliu:

/Android/data//files/: tn package nhdng theo kiu trong

java

Lu : cnphi khai bo quyn truy cp trong manifest

Thao kho : http://www.youtube.com/watch?v=_WtTmPmr-zI&feature=relmfu

http://www.youtube.com/watch?v=_WtTmPmr-zI&feature=relmfuhttp://www.youtube.com/watch?v=_WtTmPmr-zI&feature=relmfuhttp://www.youtube.com/watch?v=_WtTmPmr-zI&feature=relmfuhttp://www.youtube.com/watch?v=_WtTmPmr-zI&feature=relmfuhttp://www.youtube.com/watch?v=_WtTmPmr-zI&feature=relmfu

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Custom Fomat text

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Spanned & HTML

Int getSpanStart(Object)

Int getSpanEnd(Object)

T[] getSpans(int start,int end,class)

Void removeSpan(Object)

Void setSpan(Object, int,int, int flags)

Editable insert(int where,Charsequence)

Editable replace(int, int, Charsequence)

Editable delete(int ,int)

Void clear()

Void clearSpans()

Immutable markup, immutable text

Mutable markup, immutable text

Immutable markup, immutable text

Spanned SpannedString

Spannable

Editable SpannableStringBuilder

SpannableString

CharSequence

Interface Implementation

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Presentation and saving

Presentation

Spanned Html.fromHtml(String)

imton m HTML sang mt

itng Spanned

Edittext.setText(Spanned)

Biudin Spanned ra bngmt

TextView

Saving

String Html.toHtml(Spanned)

Biudinitng Spannedbng m HTML

ny ta c thluitngvo CSDL v ln sau gili

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Database

Html.toHtml

Html.fromHtml

Ngi dng thao tcvi Edit text

Convert to Html

SpannedString

String

Spanned

Presentation

Saving

Convert to Spanned

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But ..

Khng phith HTML no cnghtrbiphngthc Html.fromHtml,Html.toHtml

Ta phi Implement interface Html.TagHandlerPublic Class myHandler implements TagHandler{

public void handleTag(boolean opening,String tag, Editableoutput,XMLreader xmlReader){

// doing somethings with tag

}

}Khi sdng Spanned Html.fromHtml(String source, ImageGetter null,myHandler handler);

phn ny ta tham kho:http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.2_r1.1/android/text/Html.java

http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.2_r1.1/android/text/Html.javahttp://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.2_r1.1/android/text/Html.javahttp://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.2_r1.1/android/text/Html.javahttp://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.2_r1.1/android/text/Html.java

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Conclusion

Phnu tin Accessing File l kthutcbn trong phttrinngdng Android

Trong phn Custom format text l gii php c nhn em a ratrong qu trnh lm Project cho ngdngNht k

Reference:

File :

Android-Chapter15-Files.pptx [Cleverland University]

http://www.ibm.com/developerworks/vn/library/x-

androidstorage/index.html

http://developer.android.com/guide/topics/data/data-storage.html

http://developer.android.com/reference/android/text

http://www.ibm.com/developerworks/vn/library/x-androidstorage/index.htmlhttp://www.ibm.com/developerworks/vn/library/x-androidstorage/index.htmlhttp://developer.android.com/guide/topics/data/data-storage.htmlhttp://developer.android.com/guide/topics/data/data-storage.htmlhttp://developer.android.com/reference/android/texthttp://developer.android.com/reference/android/texthttp://developer.android.com/reference/android/texthttp://developer.android.com/guide/topics/data/data-storage.htmlhttp://developer.android.com/guide/topics/data/data-storage.htmlhttp://developer.android.com/guide/topics/data/data-storage.htmlhttp://www.ibm.com/developerworks/vn/library/x-androidstorage/index.htmlhttp://www.ibm.com/developerworks/vn/library/x-androidstorage/index.htmlhttp://www.ibm.com/developerworks/vn/library/x-androidstorage/index.htmlhttp://www.ibm.com/developerworks/vn/library/x-androidstorage/index.htmlhttp://www.ibm.com/developerworks/vn/library/x-androidstorage/index.html

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Thank you!