Summary of trivial knowledge points in Android programming (5)

1. No animation is required to start the program.

Java code

1. Myintent. setflags (intent. flag_activity_no_animation); // 1.5 should be used, so that no animation effect can be obtained.
2. Getwindow (). setwindowanimations (1) // 1.6 should be used. Do not forget to put it in Activity

 

2. Create a directory for the SD card

Java code

1. File wallpaperdirectory = new file ("/sdcard/wallpaper /");
2. Wallpaperdirectory. mkdirs ();
3. File outputfile = new file (wallpaperdirectory, filename );
4. Fileoutputstream Fos = new fileoutputstream (outputfile );

Be sure to add permissions.

XML Code

1. <Uses-Permission Android: Name = "android. Permission. write_external_storage"/>

 

3. crossline effect in the middle of the text

Java code

1. Pricetv. settext ("Price: RMB 2.00 ");
2. Pricetv. getpaint (). setflags (paint. strike_thru_text_flag );

 

4. Use transactions to operate SQLite databases in Android

Java code

1. Sqlitedatabase DB = ....;
2. DB. begintransaction (); // start the transaction
3. Try {
4. Db.exe csql ("insert into person (name, age) values (?,?) ", New object [] {" James ",
6. 4 });
7. Db.exe csql ("Update person set name =? Where personid =? ", New object [] {" Li Si ", 1 });
8. DB. settransactionsuccessful (); // call this method to submit the current task when it is executed to endtransaction ().
10. If this method is not called, the transaction will be rolled back.
11. } Finally {
12. DB. endtransaction (); // The transaction identifier determines whether to commit or roll back the transaction.
13. }
14. DB. Close ();

 

5. Questions about sms smessage

Java code

1. Public void onreceive (context, intent ){
2. // Todo auto-generated method stub
3. Log. D (TAG, "---> onreceive, SMS reach ");
5. Bundle bundle = intent. getextras ();
6. If (bundle! = NULL ){
7. Object [] PDUS = (object []) bundle. Get ("PDUS ");
8. Smsmessage [] messages = new smsmessage [PDUS. Length];
9. For (INT I = 0; I <PDUS. length; I ++ ){
10. Messages = smsmessage. createfrompdu (byte []) PDUS );
11. }
12. For (smsmessage: messages ){
13. From = smsmessage. getdisplayoriginatingaddress ();
14. Data = smsmessage. getdisplaymessagebody (). Trim ();
15. Log. D (TAG, from + "" + data );
16. // Process content
17. Response (context, data );
18. }
19. }
20. }

 

6. webview in Android supports multi-touch:

Java code

1. Public class usingmywebview extends activity {
2. Private webview mwebview;
3. @ Override
4. Public void oncreate (bundle savedinstancestate ){
5. Super. oncreate (savedinstancestate );
6. Setcontentview (R. layout. Main );
8. // Get Web View
9. Mwebview = (webview) findviewbyid (R. Id. mywebview); // This is the ID you gave to the webview in the main. xml
10. Mwebview. getsettings (). setjavascriptenabled (true );
11. Mwebview. getsettings (). setsuppzoom zoom (true );
12. // Zoom control on Web (you don't need this if Rom supports multi-touch
13. Mwebview. getsettings (). setbuiltinzoomcontrols (true); // enable multitouch if supported by Rom
14. // Load URL
15. Mwebview. loadurl ("http://www.firstdroid.com/advertisement.htm ");
16. }
17. }

7. Android program automatically starts at startup:

XML Code

1. <Cycler Android: Name = ". bootbroadcastreceiver">
2. <Intent-filter>
3. <Action Android: Name = "android. Intent. Action. boot_completed"/>
4. </Intent-filter>
5. </Cycler>

Add the receiver tag to the application tag of the manifest file, and Android: Name specifies a broadcastreceiver. filter the broadcast that is completed when the device is started.

Java code

1. Package com. jftt. bootstart;
3. Import Android. content. broadcastreceiver;
4. Import Android. content. context;
5. Import Android. content. intent;
7. Public class bootbroadcastreceiver extends broadcastreceiver {
8. Static final string action = "android. Intent. Action. boot_completed ";
10. @ Override
11. Public void onreceive (context, intent ){
12. If (intent. getaction (). Equals (Action )){
13. Intent sayhellointent = new intent (context, bootstart. Class); // specify the activity page to be enabled
14. Sayhellointent. addflags (intent. flag_activity_new_task );
16. Context. startactivity (sayhellointent );
17. }
18. }
19. }