accessing file
TRANSCRIPT
-
7/31/2019 Accessing File
1/18
Acessing file
Cource: Embedded Systems and Realtime
Instructor: Dr. Tran Thi Minh Chau
Student : Nguyen Van Lan
Email: [email protected]
-
7/31/2019 Accessing File
2/18
Out line:
Data Storage & Accessing File
Shared Preferences
Internal Storage
External Storage
SQLite Databases
Custom Format Text ( My Project)
HTML & SpannedDemo
-
7/31/2019 Accessing File
3/18
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
-
7/31/2019 Accessing File
4/18
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
-
7/31/2019 Accessing File
5/18
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 -
7/31/2019 Accessing File
6/18
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
-
7/31/2019 Accessing File
7/18
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
-
7/31/2019 Accessing File
8/18
-
7/31/2019 Accessing File
9/18
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
-
7/31/2019 Accessing File
10/18
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;
}
-
7/31/2019 Accessing File
11/18
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 -
7/31/2019 Accessing File
12/18
Custom Fomat text
-
7/31/2019 Accessing File
13/18
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
-
7/31/2019 Accessing File
14/18
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
-
7/31/2019 Accessing File
15/18
Database
Html.toHtml
Html.fromHtml
Ngi dng thao tcvi Edit text
Convert to Html
SpannedString
String
Spanned
Presentation
Saving
Convert to Spanned
-
7/31/2019 Accessing File
16/18
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 -
7/31/2019 Accessing File
17/18
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 -
7/31/2019 Accessing File
18/18
Thank you!