This class java.util.Random provides methods that generates pseudo-random numbers of different types, such as int, long, double, and float.
It support two public constructor:
Random() - Construct a random generator with the current time of day in milliseconds as the initial state.
Random(long seed) - Construct a random generator with the given seed as the initial state.
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Generate Random number"
android:id="@+id/generate"
/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/generatenumber"
/>
</LinearLayout>
AndroidRandom.java
package com.exercise.AndroidRandom;
import java.util.Random;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class AndroidRandom extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final Random myRandom = new Random();
Button buttonGenerate = (Button)findViewById(R.id.generate);
final TextView textGenerateNumber = (TextView)findViewById(R.id.generatenumber);
buttonGenerate.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
textGenerateNumber.setText(String.valueOf(myRandom.nextInt()));
}});
}
}
Related:
- Generate sequence of Random number.
9 comments:
quick question what If i want to generate a random number of 12 characters and create a database and every random number generated is saved into that database?
hello chilltime,
To generate sequence of random number, please refer Generate Random number, Random().
Gore database, pls refer A simple example using Android's SQLite database
But if you only want to save 12 random number, I think SharedPreferences.Editor is much more easy.
Hope can help.
The method setOnClickListener(View.OnClickListener) in the type View is not applicable for the arguments (new DialogInterface.OnClickListener(){})
why won't this pass?
hello MooseAMoose,
DialogInterface!? are u mis-typing? or import a wrong class?
I copied and pasted this right into eclipse. ctrl+shift+o and then tried to run.
01-03 21:52:08.546: E/AndroidRuntime(415): FATAL EXCEPTION: main
01-03 21:52:08.546: E/AndroidRuntime(415): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{bb.bb.bb/bb.bb.bb.BbActivity}: java.lang.ClassNotFoundException: bb.bb.bb.BbActivity in loader dalvik.system.PathClassLoader[/data/app/bb.bb.bb-1.apk]
01-03 21:52:08.546: E/AndroidRuntime(415): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585)
01-03 21:52:08.546: E/AndroidRuntime(415): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
01-03 21:52:08.546: E/AndroidRuntime(415): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
01-03 21:52:08.546: E/AndroidRuntime(415): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
01-03 21:52:08.546: E/AndroidRuntime(415): at android.os.Handler.dispatchMessage(Handler.java:99)
01-03 21:52:08.546: E/AndroidRuntime(415): at android.os.Looper.loop(Looper.java:123)
01-03 21:52:08.546: E/AndroidRuntime(415): at android.app.ActivityThread.main(ActivityThread.java:4627)
01-03 21:52:08.546: E/AndroidRuntime(415): at java.lang.reflect.Method.invokeNative(Native Method)
01-03 21:52:08.546: E/AndroidRuntime(415): at java.lang.reflect.Method.invoke(Method.java:521)
01-03 21:52:08.546: E/AndroidRuntime(415): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
01-03 21:52:08.546: E/AndroidRuntime(415): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
01-03 21:52:08.546: E/AndroidRuntime(415): at dalvik.system.NativeStart.main(Native Method)
01-03 21:52:08.546: E/AndroidRuntime(415): Caused by: java.lang.ClassNotFoundException: bb.bb.bb.BbActivity in loader dalvik.system.PathClassLoader[/data/app/bb.bb.bb-1.apk]
01-03 21:52:08.546: E/AndroidRuntime(415): at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243)
01-03 21:52:08.546: E/AndroidRuntime(415): at java.lang.ClassLoader.loadClass(ClassLoader.java:573)
01-03 21:52:08.546: E/AndroidRuntime(415): at java.lang.ClassLoader.loadClass(ClassLoader.java:532)
01-03 21:52:08.546: E/AndroidRuntime(415): at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
01-03 21:52:08.546: E/AndroidRuntime(415): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577)
01-03 21:52:08.546: E/AndroidRuntime(415): ... 11 more
how to generate 20 random question and its 4 options out of 100 given questions with each 4 options from sqlite database
How can I generate random numbers without going back the same number? For example, I have 20 numbers. When "15" and "6" is already picked out, it will not be printed again to the next process output. Help please, thank you
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