Okhelp.cz

Recepty, články, nápady, programování. Dříve dum-zahrada, finance, internet a know-how.okhelp.cz Pro lepší výsledky hledání používejte i diakritiku.

Java Basic Rules


AD MOB


// file name MyFirstClass.java

import java.util.*;
import java.lang.Math;
import java.io.*;
import javax.swing.*;

public class MyFirstClass{ // start of program
  public static void main(String[] args) { // basic  function main

// variables and calculation
int a=2;
int b=3;
int c=Integer.parseInt(JOptionPane.showInputDialog(" Put number: ", "1"));
System.out.println("Number is: "+c);
System.out.println(a+" * "+b+" = "+(a*b));
System.out.println("a^3 "+Math.pow(a,b));

//array
int[] array_my=new int[10];
array_my[0]=3;
array_my[1]=5;
System.out.println("Number of elements "+array_my.length+" 1 + 2 element of array "+(array_my[0]+array_my[1]));

//strings
String txt="Quick red fox";
String txt2=JOptionPane.showInputDialog("Write text: ", "word");
System.out.println("Text is: "+txt2);
String[] count_of_word=txt.split(" ");
System.out.println("Length: "+txt.length()+" Count of words "+count_of_word.length);
System.out.println(txt +" -> "+txt.replace("red","brown"));
System.out.println("First 5 chars of string is: "+ txt.substring(0,5));

//for a if
for(int i=0; i<10;i++){
	if(i==3)System.out.println("i equal "+i);
	}

// file
try {
  File soubor=new File("some_file.txt");
  if(!soubor.exists()){
	System.out.println("File dont exist");
  }
  else { // utf-8 encoding
    BufferedReader in1 = new BufferedReader(new InputStreamReader(new FileInputStream(soubor),"UTF-8"));
    BufferedWriter out1 = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("zapis.txt"),"UTF-8"));
    String str;
      while ((str = in1.readLine())!=null){
        System.out.println(str);
        out1.write(str+"

"); } in1.close(); out1.close(); } } catch(IOException e){System.out.println("Error " + e);} // dir File pathName = new File("some_dir"); String[] fileNames = pathName.list(); if(pathName.exists()) System.out.println("Name of first file in \"some_dir\": "+fileNames[0]); else System.out.println("dir not exist"); //function int nResult = calculateMyFc(3,5); System.out.println("Result of function: "+nResult); } // end of function main // new function , you can add to end MyFc = my function public static int calculateMyFc(int a, int b){ return (a+b); } } // end of class of program

397LW NO topic_id




AD

Další témata ....(Topics)


108

Turn screen ON OFF Android sample code | turn-screen-on-off-android-sample-code


WakeLock, PowerManager,uses-permission Android sample.
Main.java

public class Main extends Activity {
	    private SensorManager mSensorManager;
	    private PowerManager mPowerManager;
	    private WindowManager mWindowManager;
	    private WakeLock mWakeLock;
	    private Button button;
	    private TextView textView;

	    /** Called when the activity is first created. */
	    @Override
	    public void onCreate(Bundle savedInstanceState) {
	        super.onCreate(savedInstanceState);
try{
	        // Get an instance of the SensorManager
	        mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);

	        // Get an instance of the PowerManager
	        mPowerManager = (PowerManager) getSystemService(POWER_SERVICE);

	        // Get an instance of the WindowManager
	        mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
	        mWindowManager.getDefaultDisplay();

	        // Create a bright wake lock
	        mWakeLock = mPowerManager.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK, getClass()
	                .getName());

	        setContentView(R.layout.main);
	        textView = (TextView)findViewById(R.id.textView1);
	        button = (Button)findViewById(R.id.button1);
	        button.setOnClickListener(mButtonStopListener);
	       
	        
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			Log.e("onCreate", e.getMessage());
		}
} // END onCreate
	    
	    View.OnClickListener mButtonStopListener = new OnClickListener() {
	    	public void onClick(View v) {
		        try {
					mWakeLock.release();
					textView.setText("mWakeLock.release()");
				} catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
					Log.e("onPause",e.getMessage());
				}
	    	
	    	}
	    };

	    @Override
	    protected void onResume() {
	        super.onResume();
	        /*
	         * when the activity is resumed, we acquire a wake-lock so that the
	         * screen stays on, since the user will likely not be fiddling with the
	         * screen or buttons.
	         */
	        
	        try {
				mWakeLock.acquire();
				textView.setText("mWakeLock.acquire()");
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
				Log.e("onResume", e.getMessage());
			}

	    }

	    @Override
	    protected void onPause() {
	        super.onPause();

	        // and release our wake-lock
	        try {
				mWakeLock.release();
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
				Log.e("onPause",e.getMessage());
			}
	    }
}



AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="//schemas.android.com/apk/res/android"
      package="cz.okhelp.Main"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="7" />
    <uses-permission android:name="android.permission.HARDWARE_TEST"></uses-permission>
<uses-permission android:name="android.permission.VIBRATE"></uses-permission>

<uses-permission android:name="android.permission.WAKE_LOCK"></uses-permission>

    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".ScreenBrightnessActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
</manifest>


386

Android Studio Gradle Download Link | android-studio-gradle-download-link


I You use offline work for better building speed of project or for other purpose
https://gradle.org/releases

Offline work:
File - Settings - Gradle
- select Use local gradle distribution
- select path Gradle home:
- check Offline work
273

Android Widget OnClick Example | android-widget-onclick-example


Open link in browser after user do click on widget area:

private Context _context;
	@Override
		public void onStart(Intent intent, int startId) {
                        _context = this;
			String definePage ="//old.chmi.cz/meteo/rad/rad_data.php";
			 Intent defineIntent = new Intent(Intent.ACTION_VIEW,
			 Uri.parse(definePage));
			 PendingIntent pendingIntent = PendingIntent.getActivity(_context,
			 0 /* no requestCode */, defineIntent, 0 /* no flags */);
			 updateViews.setOnClickPendingIntent(R.id.widget, pendingIntent);

251

How to create icon for Android apps | how-to-create-icon-for-android-apps


First cteate big icon 512x512 px formtat .PGN in graphics editor as Photoshop, Gimp, Piant.NET and save image.
If you create new project via Eclipse and choice your 512x512 image for ic_launcher.
Eclipse will make all icons from this image for new application very well.

create-custom-icon-eclipse

create-custom-icon-eclipse
148

Crop cropped cut bitmap image pictures Android example | crop-cropped-cut-bitmap-image-pictures-android-example


Cut, shear, clip, snip, crop a bitmap, picture, image Android example

public class ApokusActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}

		@Override
		protected void onDraw(Canvas canvas) {
			Paint paint = new Paint();

			canvas.drawColor(Color.YELLOW);


			// you need to insert a image flower_blue into res/drawable folder
			paint.setFilterBitmap(true);
			Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),
					R.drawable.flower_blue);

			Bitmap croppedBmp = Bitmap.createBitmap(bitmapOrg, 0, 0,
					bitmapOrg.getWidth() / 2, bitmapOrg.getHeight());
			int h = bitmapOrg.getHeight();
			canvas.drawBitmap(bitmapOrg, 10, 10, paint);
			canvas.drawBitmap(croppedBmp, 10, 10 + h + 10, paint);

		}

	}
}



crop bitmap android


Editace: 2013-12-09 11:06:19
Počet článků v kategorii: 397
Url:java-basic-rules

AD
11 Share
Share
Tweet