Array copy to Array Java Android example
AD MOB
String[] source = {"Hello","world","by","Android"};
String[] destination = new String[source.length];
System.arraycopy(source, 0, destination, 0, source.length);
396LW NO topic_id
AD
Další témata ....(Topics)
Activities launcher
public class MainActivity extends ListActivity {
private class Sample {
private CharSequence title;
private Class<? extends Activity> activityClass;
public Sample(int titleResId, Class<? extends Activity> activityClass) {
this.activityClass = activityClass;
this.title = getResources().getString(titleResId);
}
@Override
public String toString() {
return title.toString();
}
}
private static Sample[] mSamples;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Instantiate the list of samples.
mSamples = new Sample[]{
new Sample(R.string.title_first_app, FirstActivity.class),
new Sample(R.string.title_second_app, SecondActivity.class),
new Sample(R.string.title_third_app, ThirdActivity.class),
};
setListAdapter(new ArrayAdapter<Sample>(this,
android.R.layout.simple_list_item_1,
android.R.id.text1,
mSamples));
}
@Override
protected void onListItemClick(ListView listView, View view, int position, long id) {
// Launch the sample associated with this list position.
startActivity(new Intent(MainActivity.this, mSamples[position].activityClass));
}
}
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);
How include layout defined in other xml file into another xml file example:
res/layout/my_layout.xml into
main.xml
res/layout/my_layout.xml into
main.xml
<include layout="@layout/my_layout" android:id="@+id/idMyLayout" />
No resource found that matches the given name - error examples.
Exist resource file?
Is code written correctly?
Exist resource file?
Is code written correctly?
// No resource found that matches the given name (at id with value @id/myButton).
android:id="@id/myButton" // invalid id notation
android:id="@+id/myButton" // correct
// No resource found that matches the given name
// (at icon with value @drawable/icons).
// exist file icons in res/drawable folder?
<application android:icon="@drawable/icons"
//No resource found that matches the given name
//(at theme with value @style/MyThem).
<activity android:name=".Main"
android:label="@string/app_name"
android:theme="@style/MyThem">
// Exist style MyThem in styles.xml ? No only MyTheme
<style name="MyTheme" parent="android:Theme">
<item name="android:windowTitleSize">50px</item>
</style>
// exist file my_background in folder drawable ?
android:background="@drawable/my_background" //
// no resource found that matches the given name(at "label" with value "@string/app_name")
// have you the string resource defined in res/values/strings.xml ?
<string name="app_name">"My App"</string>
Show keyboard if WebView input have focus Android apps development example source code.
WebView webview;
//in onCreate
webview = (WebView) findViewById(R.id.idWebviewPda);
webview.getSettings().setJavaScriptEnabled(true);
webview.loadUrl("//android.okhelp.cz");
webview.requestFocus(View.FOCUS_DOWN);
webview.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_UP:
if (!v.hasFocus()) {
v.requestFocus();
}
break;
}
return false;
}
});
Editace: 2011-11-20 11:05:23
Počet článků v kategorii: 396
Url:array-copy-to-array-java-android-example
AD