Resource int R.string.app_name to String Android example
R.string.app_name to String example.
MyActivity.java
res/values/string.xml
MyActivity.java
Resources res = getResources();
String sText = res.getString(R.string.app_name);
res/values/string.xml
<resources>
<string name="app_name">My app name</string>
</resources>
396LW NO topic_id
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Old code with HashMap
Lint warning:
Use new SparseArray(...) instead for better performance
Issue: Looks for opportunities to replace HashMaps with the more efficient SparseArray
Id: UseSparseArrays
New code with SparseArray
SparseArray methods:
//developer.android.com/reference/android/util/SparseArray.html
Map<Integer, Bitmap> _bitmapCache = new HashMap<Integer, Bitmap>();
private void fillBitmapCache() {
_bitmapCache.put(R.drawable.icon, BitmapFactory.decodeResource(getResources(), R.drawable.icon));
_bitmapCache.put(R.drawable.abstrakt, BitmapFactory.decodeResource(getResources(), R.drawable.abstrakt));
_bitmapCache.put(R.drawable.wallpaper, BitmapFactory.decodeResource(getResources(), R.drawable.wallpaper));
_bitmapCache.put(R.drawable.scissors, BitmapFactory.decodeResource(getResources(),
}
Bitmap bm = _bitmapCache.get(R.drawable.icon);
Lint warning:
Use new SparseArray
Issue: Looks for opportunities to replace HashMaps with the more efficient SparseArray
Id: UseSparseArrays
New code with SparseArray
SparseArray<Bitmap> _bitmapCache = new SparseArray<Bitmap>();
private void fillBitmapCache() {
_bitmapCache.put(R.drawable.icon, BitmapFactory.decodeResource(getResources(), R.drawable.icon));
_bitmapCache.put(R.drawable.abstrakt, BitmapFactory.decodeResource(getResources(), R.drawable.abstrakt));
_bitmapCache.put(R.drawable.wallpaper, BitmapFactory.decodeResource(getResources(), R.drawable.wallpaper));
_bitmapCache.put(R.drawable.scissors, BitmapFactory.decodeResource(getResources(),
}
Bitmap bm = _bitmapCache.get(R.drawable.icon);
SparseArray methods:
//developer.android.com/reference/android/util/SparseArray.html
If Android emulator freezes at startup, try create new virtual device with smaller memory and cpu usage, or select older version of Android, or buy new pc with higher performance.
- open AVD MANAGER
- press Create Virtual Device
- select Device with small memory usage (e.g. 480x800 of resolution) - Next
- check - Show downloadable ....
- Download - lower version of system Android, select, press - Next
- check data, Show Advanced Settings, check Use host... and press Finish
1.) Try delete some apps from Android emulator (can from Eclipse DDMS perspective
- File Explorer tab - data/apps folder path )
2.) Try resize emulator internal storage or SD card storage to hight size
3.)Try add to AndroidManifest.xml android:installLocation="preferExternal"
4.) Try resize particion from Eclipse
Preferences,
select Android- Launch
Add "-partition-size 1024" into "Default emulator option” field.
Click "Apply” and use your emulator as usual
- File Explorer tab - data/apps folder path )
2.) Try resize emulator internal storage or SD card storage to hight size
3.)Try add to AndroidManifest.xml android:installLocation="preferExternal"
<manifest xmlns:android="//schemas.android.com/apk/res/android"
package="com.myweb.mypackage"
android:installLocation="preferExternal"
4.) Try resize particion from Eclipse
Preferences,
select Android- Launch
Add "-partition-size 1024" into "Default emulator option” field.
Click "Apply” and use your emulator as usual
Terms Screen size, density, density independent pixel, resolution as a picture - pictogram.
Test your knowledge
Q: How to find out the phone screen size?
A: (By length of display diagonale in inch - Not to measure a diagonal of device!!!)
Q: What resolution has 720 x 1280 display?
A: (921600 pixels)
Q: What does it mean "240 dpi" screen density?
A: (Display have density 240 x 240 dots - "Tri-color LED etc." - per every physical (real) square inch. If you have icon 240x240 pixels, this will just occupy an area of one square inch on the display.)
Q: Phone have screen density 240 dpi. Image for 160 dpi screen density have size 128x 128 pixels. What will be the size of the image for 240 dpi screen density?
A: (Calculate the virtual pixels size. 128 * (240/160) = 192. You have to resize image to new size 192 x 192 physical pixels and put into folder drawable-hdpi (high) ~240dpi for phone with screen density 240 dpi. ) or use density independend pixels 128dp x 128dp.
Test your knowledge
Q: How to find out the phone screen size?
A: (By length of display diagonale in inch - Not to measure a diagonal of device!!!)
Q: What resolution has 720 x 1280 display?
A: (921600 pixels)
Q: What does it mean "240 dpi" screen density?
A: (Display have density 240 x 240 dots - "Tri-color LED etc." - per every physical (real) square inch. If you have icon 240x240 pixels, this will just occupy an area of one square inch on the display.)
Q: Phone have screen density 240 dpi. Image for 160 dpi screen density have size 128x 128 pixels. What will be the size of the image for 240 dpi screen density?
A: (Calculate the virtual pixels size. 128 * (240/160) = 192. You have to resize image to new size 192 x 192 physical pixels and put into folder drawable-hdpi (high) ~240dpi for phone with screen density 240 dpi. ) or use density independend pixels 128dp x 128dp.
Spinner in Android application is equivalent of ComboBox in WinApi.
Spinner get selected item to string example.
Spinner get selected item position to int example.
Main activity class MainComboBox.java
File MyOnItemSelectedListener.java
strings.xml
main.xml
Spinner get selected item to string example.
Spinner get selected item position to int example.
Main activity class MainComboBox.java
public class MainComboBox extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Spinner spinner = (Spinner) findViewById(R.id.spinner);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
this, R.array.countries_array, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new MyOnItemSelectedListener());
Button myButton =(Button)findViewById(R.id.button1);
myButton.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
Spinner sp = (Spinner)findViewById(R.id.spinner);
String spinnerString = null;
spinnerString = sp.getSelectedItem().toString();
int nPos = sp.getSelectedItemPosition();
Toast.makeText(getApplicationContext(), "getSelectedItem=" + spinnerString,
Toast.LENGTH_LONG).show();
Toast.makeText(getApplicationContext(), "getSelectedItemPosition=" + nPos,
Toast.LENGTH_LONG).show();
}
});
}
}
File MyOnItemSelectedListener.java
public class MyOnItemSelectedListener implements OnItemSelectedListener {
public void onItemSelected(AdapterView<?> parent,
View view, int pos, long id) {
Toast.makeText(parent.getContext(), "Item is " +
parent.getItemAtPosition(pos).toString(), Toast.LENGTH_LONG).show();
}
public void onNothingSelected(AdapterView parent) {
// Do nothing.
}
}
strings.xml
<resources>
<string name="hello">Hello World, MainComboBox!</string>
<string name="app_name">ComboBox</string>
<string name="prompt">Choose a country</string>
<string-array name="countries_array">
<item>China</item>
<item>India</item>
<item>USA</item>
<item>Indonesia</item>
<item>Brazil</item>
<item>Pakistan</item>
<item>Nigeria</item>
<item>Bangladesh</item>
<item>Russia</item>
</string-array>
</resources>
main.xml
<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
android:orientation="vertical"
android:padding="10dip"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dip"
android:text="@string/prompt"
/>
<Spinner
android:id="@+id/spinner"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:prompt="@string/prompt"
/>
<Button android:text="Button" android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
</LinearLayout>
Editace: 2011-11-07 08:59:41
Počet článků v kategorii: 396
Url:resource-int-r-string-app_name-to-string-android-example
