lacklack
ActionBarActivity deprecated: Use AppCompatActivity instead
source
Add a comment for a button press using Toast: source
Action Bar icons not displaying: add xmlns:app=”http://schemas.android.com/apk/res-auto” to schema, then change android:showAsAction to app:showAsAction, source
-The use of application icon plus title as a standard layout is discouraged on API 21 devices and newer. source, Gabriele, design guidelines
Scroll text screen: add two properties to the textview:
android:maxLines = “AN_INTEGER”
android:scrollbars = “vertical”
then add foo_variable.setMovementMethod(new ScrollingMovementMethod()); to your java call. source
int min = 65;
int max = 80;
Random r = new Random();
int i1 = r.nextInt(max – min + 1) + min; source
convert float to 2 sig digits: source
String.format(“%.2f”, floatValue);
increase font size of Toast: source
Toast toast = Toast.makeText(context, R.string.yummyToast, Toast.LENGTH_SHORT);
LinearLayout toastLayout = (LinearLayout) toast.getView();
TextView toastTV = (TextView) toastLayout.getChildAt(0);
toastTV.setTextSize(30);
toast.show();
Square Root function: source
xconv = Math.sqrt(xconv);
float constant: 1.2f;
Speed Equation for Accelerometer: source
Formatting in a TextView
\n: newline
\t: new tab
\b backspace
\t horizontal tab
\n linefeed
\f form feed
\r carriage return
\” double quote
\’ single quote
\\ backslash
Java Smoothing Low Pass filter, source
-pretty much a very common DSP low pass filter, lots of resources. I had to change the alpha value for the z component as my accelerometer was too jumpy.
Call a class from another class: source
Class2 cls2= new Class2();
cls2.UpdateEmployee();
Where to do init stuff in Android: source onCreate is the place.
Declare an Array: source
int[] myIntArray = new int[3];
Invoke a Method with an Array parameter:
Simple onClick Button: source
Android Layouts: source
Return 2 values from a Method: source
-put the 2 values into a class, send the class back
Restore onCreate() after orientation change: sourcesee Robert
Change min API level: source, Mauricio and Scotti. I finally got my Nexus One (API8, yes, very old), to connect to Ubuntu 14.04, so needed to know how to degrade my apps down to API8.
Samsung built-in sensor test: source, second source
*#0*#
Initialize arrays: source
-You need to initialize all arrays in java before you use them. Otherwise you get a null point exception.
Math functions:
Math.sqrt: square root
Math.pow(a, b): to the power of
Math.log: logarithmic
Get Android Studio to run faster: source, Gradle offline work really made things faster.
in Settext, when concat R.string.label (from strings.xml) put into the getString() or you’ll get a strange number. source
Scientific Notation source, convert scientific notation to long: (long)1e9
XML Comments source
Where to put
…
Add vibrate to the app source
OnAccuracyChanged Code: source. It seems few people (1) actually code this, though it is available in all code snippets
Log.d(“Sensor Accuracy”, String.format(“onAccuracyChanged sensor: %s accuracy: %d”,
sensor, accuracy));
Log.d(“TestingArea”,”onAccuracyChanged: ” + sensor +
” has accuracy: ” + accuracy); source
Unfortunately, there seem to be some devices that always report SENSOR_STATUS_UNRELIABLE and others that always report SENSOR_STATUS_ACCURACY_HIGH. Don’t place too much confidence in the accuracy status. source
Copy Project to another name: I still cannot do this. The posted solutions do not redo file links. This is a known bug. I’ll have to try this the next time: possible workaround
Layout Heights and weights, source, Ian, source
-you can use layout_weight to proportion parts of yourview, but you must also make layout_height or width = 0dp, or the resulting proportions will be backwards!
Adding Material Icons to Android Studio, yesitisme, source>
-downloaded Material icons from Google’s GIT, then extracted them to my AS directory. From AS, new, Image Asset, Image file (browse to your directory) and they’ll all be there. The Material design icons list
-good icon search here at icons8.com
-different dpi required, source
HTML in Android: Not all html tags are supported. I especially wanted lists, but no, they are not available. source
“Unable to find explicit activity class…have you declared this activity in your AndroidManifest.xml?” Yes, this error crashes your app with no further info. I forgot to add my class to the manifest.xml. source
Spinner/Drop down box: source, Abishek
-I only need it for numbers
Passing data back from a different class, like from a settings page: source, Nishant
String to integer: source, rob
Spinner items font size increase: source, VJ
Trying to pass a value from Settings to Main activity: source
Pass value from Main to Settings activity: source, Scenic
Make link clickable in textview: source, Mohammed
-android:autoLink=”web”
android:linksClickable=”true”
-tried this to hide the url, but it did not work
Make font larger using : source
Allow images and text to scroll, use a scrollview: source, Flio
Convert R.string from reference to string: source, Skidadon
getResources().getString(R.string.title_activity)