float in Java example code
Android development
Java float is 32 bit single precision type and used when fractional precision calculation is required.
Java float je 32 bitů veliké číslo sloužící především pro přesný výsledek za desetinnou tečkou například při dělení čísel. Pro větší přesnost použíijte 64 bitový typ Double.
Java float is 32 bit single precision type and used when fractional precision calculation is required.
Java float je 32 bitů veliké číslo sloužící především pro přesný výsledek za desetinnou tečkou například při dělení čísel. Pro větší přesnost použíijte 64 bitový typ Double.
// declaration and assignment of value type float
float x = 18.41785f;
//print formated value
System.out.printf("The value of x is %.3f%n", x); // 18.418
// declaring more variables in single statement
float f1 = 12.4F, f2 = 564.5F, f3 = 14.589F;
// float range of value
System.out.println(Float.MIN_VALUE); // 4E-45
System.out.println(Float.MAX_VALUE); // 4028235E38
// is NaN Not-a-Number
float f = (float) Math.sqrt(-15);
boolean bNaN = Float.isNaN(f);
System.out.print(bNaN); // true
// check if a string is a valid number in Java example
// convert string to float Java example
String sF = "12.8";
float fParse = Float.parseFloat(sF);
// convert strings to numbers
String sFl = "15.48";
float fFromString = (Float.valueOf(sFl)).floatValue();
// float to string in Java example code
Float fObj = new Float(68.5);
String str = fObj.toString();
// else
Float fS = 11.6f;
String sFloat = fS.toString();
// compare two float variables
Float fComp1 = 4.3f;
if(fComp1.equals(4.3f))
System.out.print("true");
// compares the two specified float values in Java example
int i = Float.compare(11.5f, 11.7f); // -1 first < second
// 0 first == second
// 1 first > second
System.out.print(i);
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Update TextView from TimerTask, Handler, schedule, run, cancel TimerTask, Android example
public class TimerActivity extends Activity {
TimerTask mTimerTask;
final Handler handler = new Handler();
Timer t = new Timer();
TextView hTextView;
TableRow hTableRow;
Button hButton, hButtonStop;
private int nCounter = 0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
hTextView = (TextView)findViewById(R.id.idTextView);
hButton = (Button)findViewById(R.id.idButton);
hButton.setOnClickListener(mButtonStartListener);
hButtonStop = (Button)findViewById(R.id.idButtonStop);
hButtonStop.setOnClickListener(mButtonStopListener);
} // end onCreate
View.OnClickListener mButtonStartListener = new OnClickListener() {
public void onClick(View v) {
doTimerTask();
}
};
View.OnClickListener mButtonStopListener = new OnClickListener() {
public void onClick(View v) {
stopTask();
}
};
public void doTimerTask(){
mTimerTask = new TimerTask() {
public void run() {
handler.post(new Runnable() {
public void run() {
nCounter++;
// update TextView
hTextView.setText("Timer: " + nCounter);
Log.d("TIMER", "TimerTask run");
}
});
}};
// public void schedule (TimerTask task, long delay, long period)
t.schedule(mTimerTask, 500, 3000); //
}
public void stopTask(){
if(mTimerTask!=null){
hTextView.setText("Timer canceled: " + nCounter);
Log.d("TIMER", "timer canceled");
mTimerTask.cancel();
}
}
}
Android app setup preferences, settings, open, read, write, onStop(), onPause(), getSharedPreferences(), SharedPreferences.Editor getInt(), getBoolean(), getString() , putInt(), putString(), putBoolean() example source code.
import android.content.SharedPreferences;
public class MainClass extends Activity {
public static final String PREFERENCES_NAME = "MyPrefsFile";
String myNewString;
int myNewInt;
Boolean myNewBool;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// read old settings if exist
SharedPreferences settings = getSharedPreferences(PREFERENCES_NAME, 0);
String sDefault = "Hello!";
String sStringFromPrefFile = settings.getString("myString", sDefault); // new text or default Hello!
int nDefaultIndex = 2; //
int nIndexFromPrefFile = settings.getInt("myInt", nDefaultIndex); // 4 or default 2
Boolean bDefault = false;
Boolean bFromPrefFile = settings.getBoolean("silentMode", bDefault); // true or default false
// new settings will saved in onStop or onPause
myNewString = "new text";
myNewInt = 4;
myNewBool = true;
}
@Override
protected void onPause() {
super.onPause();
Toast.makeText(getApplicationContext(), "onPause "
, Toast.LENGTH_SHORT).show();
savePreferences();
}
@Override
protected void onStop() {
super.onStop();
savePreferences();
}
/**save settings*/
public void savePreferences(){
try {
SharedPreferences settings = getSharedPreferences(PREFERENCES_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString("myString", myNewString);
editor.putInt("nMyInt", myNewInt);
editor.putBoolean("silentMode", myNewBool); //
editor.commit();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
| Brand | Samsung |
| Model (codename) | Galaxy Mini (S5570) |
| Price (cena, včetně DPH) | 3500 / 06.2012 |
| Display size in Inch (v palcích) | 3.14 |
| Display-resolution | 240x320 |
| Dotek-typ | kapacitní |
| CPU typ | MSM7227 |
| CPU MHz | 600 |
| CPU core | |
| L2 cache | yes |
| RAM | 256 |
| ROM | 512 |
| GPU | Adreno 200 |
| NenaMark2 Benchmark | |
| GPU-GLBenchmark | |
| Baterie mAh | 1200 |
| Foto MPx | 3 |
| Autofocus | no |
| Video | QVGA (320 x 240) při 15 frames/s |
| Official Android ICS | Android Froyo 2.2 |
| CyanogenMod support | yes |
| Dotek-prstů-max | Dual-touch (two fingers) |
| Display-ppi | 127 |
| Display-retina | 39% |
| Networks | GSM&EDGE (850 / 900 / 1.800 / 1.900 MHz) 3G (900 / 2.100 MHz) |
| Connectivity | Bluetooth V2.1 , USB V2.0 , USB mass storage , SyncML(DM) , WIFI , AGPS, 3.5 mm jack |
| Note |
Samsung S5570 Galaxy Mini - image
AdMob in Android emulator not visible?
You have to using some from this libraries:
GoogleAdMobAdsSdk-4.3.1.jar
GoogleAdMobAdsSdk-6.0.1.jar
GoogleAdMobAdsSdk-6.2.1.jar
AndroidManifest.xml
onCreate in your Activity.java
main.xml (res/layout)
You have to using some from this libraries:
GoogleAdMobAdsSdk-4.3.1.jar
GoogleAdMobAdsSdk-6.0.1.jar
GoogleAdMobAdsSdk-6.2.1.jar
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="//schemas.android.com/apk/res/android"
package="cz.okhelp.admob"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="13"
android:targetSdkVersion="16"/>
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<application android:icon="@drawable/ic_launcher" android:label="@string/app_name">
<meta-data
android:value="a14d932xxxxxxxx"
android:name="ADMOB_PUBLISHER_ID" />
<activity android:name=".AdmobActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="com.google.ads.AdActivity"
android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize" />
</application>
</manifest>
onCreate in your Activity.java
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
AdViw adView = new AdView(this, AdSize.BANNER, "a14d932xxxxxxxxx");//MY_AD_UNIT_ID
LinearLayout layout = (LinearLayout)findViewById(R.id.idReklamaLayout);
// Add the adView to it
layout.addView(adView);
// Initiate a generic request to load it with an ad
AdRequest adRequest = new AdRequest();
//adRequest.setTesting(true);
adRequest.setGender(AdRequest.Gender.MALE);
adView.loadAd(adRequest);
}
main.xml (res/layout)
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello" />
<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
android:id="@+id/idReklamaLayout"
android:orientation="vertical"
android:gravity="center"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="3" />
</LinearLayout>
C:\documents\workspace\.metadata\.plugins\org.eclipse.core.runtime\.settings\org.eclipse.jdt.ui.prefs
Editace: 2011-09-26 20:49:50
Počet článků v kategorii: 396
Url:float-in-java-example-code
