how to transfer messages from android to android via bluetooth

wasThis is the main code in the first activityThe code for the second activity isEdit without any errors, but run the program, the following interface appearsWhen you click the Calculate button, the following conditions occur:Check for Logcat hints in eclipseThe reason for the error is probably that an activity parameter is not passed to the second activity, causing the second activity to receive a null parameter, and then cause the program to run an error, after its own careful check out, the

---restore content starts---First of all, to install the software, feel I have found some of the textbooks are relatively simple, after some detours, decided to follow this Baidu experience toA detailed tutorial on Android development environmentHttp://jingyan.baidu.com/article/948f592448183bd80ff5f9d1.htmlThe place to compare pits is that the Android SDK is downloaded, and after clicking on "SDK Manager.ex

=NewBigInteger (1/*Positive*/, pubkey.getencoded ()). ToString (16);55 56//Pin It!57 58Final Booleanexpected =pub_key.equalsignorecase (encoded);59 60if(!expected) {61 62Throw NewCertificateexception ("checkservertrusted:expected public key:" + Pub_key + ", got public key:" +encoded);63 64 }65 66 }67 68}2 Certificate Locking: The issuing of public key certificates for the client is stored in the mobile client (using KeyStore), when HTTPS communication, in the client code to secure t

1, must find a common on Android and JDK encryption algorithm, later found http://www.cnblogs.com/hjtdlx/p/3926141.html this article, try it, it can be used. 2, Android and server side of the transmission in JSON format, in addition to encryption to verify whether or not modified. Transfer format: {PARAMS:XXX,SIGN:XXX} Where the params is DES3 encrypted JSON d

Years ago, I studied how Android can implement the Wireless Data Transfer Function and wrote a demo. I have nothing to do with it recently. I want to sort it out and share it with you. Early research found that Android has the following technologies to achieve wireless data transfer: 1. Bluetooth has been used for a lo

Two applications between the value, in fact, the title is too water, the professional argument is "two process how to pass the value", what?! It's not professional enough, okay, you're kinky! "Interprocess communication" is actually more professional, this time you always satisfied! Incidentally, abbreviated to IPC:inter-process communication. Brothers, if you find this article from search engines or other sources, it means that your Android technolog

Original: http://blog.csdn.net/xueerfei008/article/details/23046341The project needs to use in the 2 activities between the data transfer, before doing are some strings and other things, the results of this card for a long time, tossing an afternoon.First: Pass bitmapThis problem is very wonderful (probably my Android level is not enough), incredibly do not error, I am directly using bundles or intent extra

This article illustrates the method of data transfer between Android implementation activities. Share to everyone for your reference. The specific analysis is as follows: First, explain the start and shutdown of activity: 1. StartActivity (Intent Intent); Start activityFinish (); End Current Activity2. Startactivityforresult (Intent Intent, int requestcode); Starts an activity with the specified request c

;ImportAndroid.widget.TextView; Public classExitextendsActivityImplementsonclicklistener{Button exitbtn; Button returnbtn; TextView Name; @Overrideprotected voidonCreate (Bundle savedinstancestate) {Super. OnCreate (savedinstancestate); Setcontentview (R.layout.activity_exit); EXITBTN=(Button) Findviewbyid (R.ID.EXITBTN); RETURNBTN=(Button) Findviewbyid (R.ID.RETURNBTN); Name=(TextView) Findviewbyid (r.id.name); String name=getintent (). Getextras (). getString ("name"); Name

Android development, often in the Java code and the JNI layer passed between the array (byte[]), a typical application is the Java layer to send the data sent to the client stream to the JNI layer, by the JNI layer socket code sent out, of course, The JNI layer also needs to return the data stream received from the socket to the Java layer. I summarized briefly, from the Java layer to the JNI layer, from the JNI layer to the Java layer, there are 3 ki

In the development of Android UI, we often encounter this requirement:Two components that support sliding, such as the ListView nested multiple Listview,listview item is a Viewpager or gallary? or ScrollView nested ScrollView and so on.In general, you may also need to support several features such as:¤ Two-layer components can slide¤ Do not let two components slide at the same time, or let two components sliding simultaneously and can adjust themselve

; @Overrideprotected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); Setcontentview (r.layout.activity_regist); Initviews ();} private void Initviews () {et_uname = (EditText) Findviewbyid (r.id.et_uname); et_upass = (EditText) Findviewbyid (r.id.et_ UPass);} public void regist (view view) {String uname = Et_uname.gettext (). toString (). Trim (); String UPass = Et_upass.gettext (). toString (). Trim (); if (Textutils.isempty (uname) | | Textutils.isempty (UPass))

For example, interface a passes value to interface b1. Interface a considerations:(1) Intent put different types of parameters with the same name parameter the last one will overwrite the previous parameter (one parameter name can only correspond to one parameter value, and multiple parameters will be overwritten by the last parameter)2. Interface B Considerations:(2) Intent get different types of parameters, only if interface a put the parameters of the type, B interface to get to the value, ot

The first is the call service for the system clipboard:Clipboardmanager Clipboardmanager=getsystemservice (Context.clipboard_service);Then it is written, taken out.It is important to note that before Android version 11, the use of the Clipboard to pass data using the SetText and GetText methods, but after version 11, the two GetText and set methods are discarded, instead of the need to use the Clipdata object to pass the data. Compared with the GetTex

Now assume that there are two classes Aclass.class and Bactivity.class, passing the value in a to the B call1, the code in Aclass.class is as followspublic class AClass implements { //Get interface Object private Onaclasslistener Aclasslistener; //Construction Method Private AClass () { } //Send data public void sends () {if (aclasslistener!= null) { aclasslistener.onaclass ("Pass the value Here"); } } For B-bound interface public void Setonaclass (Onac

closed. Test results:java : Java new 5000s waste 3ms c++ : c++ new 5000s Waste 18ms java : java new 10000s Waste 5ms c++ : c++ new 10000s waste 24ms Span class= "http" >java : java new 50000s waste 44ms c++ : c++ new 50000s waste 121ms java : java new 100000s waste 65ms c++ : c++ new 100000s waste 259ms This time, the results show that if the cache method ID and Jclass can be shortened by half the time. But still less fast than Java. It's also good to understand that C + + creat

Set values by Putextra, get values by GetextraPutextra need to set the key-value pair, Getextra by the corresponding key to get the passed value (directly between the Getextra plus the value type you want to get)1. Open another activity in one activity through Startactivityforresult ()2. This method usually receives two parameters, the first one is the intent object, the second is the Requestcode3. In the first activity, rewrite the Onactivityresult method, by switch to determine the transmitted

Activity jumps and passes values. Mainly through the intent class. The role of intent is to activate the component and the accompanying data.First, activity jumpsMethod OneIntent Intent = new Intent (a.this, B.class);StartActivity (Intent)Method TwoIntent Intent = new Intent ();Intent.setclass (A.this, B.class);StartActivity (Intent);Implementation from a jump to B (A, B are inherited from activity)II. Transmission of dataActivity A transmits dataMethod OneIntent Intent = new Intent ();Intent.se

I. Public Intent PutExtra (String name, double[] value)Set Method Intent.putextra ("AAA", "bbbb");Get Method This.getintent (). Getcharsequenceextra ("AAA")Ii. public Intent Putextras (Bundle extras)Setup MethodBUNDLE BD = new bundle ();bd.putstring ("AAA", "bbbb");Intent.putextras (BD);Get MethodBundle bd=this.getintent (). Getextras ();bd.getstring ("AAA")); Iii. SummaryThe band S has to bind the data through a bundle. ---Putextra and Putextras of Android