You need to override onSaveInstanceState(Bundle savedInstanceState)
and write the application state values you want to change to the Bundle
parameter like this:
@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
// Save UI state changes to the savedInstanceState.
// This bundle will be passed to onCreate if the process is
// killed and restarted.
savedInstanceState.putBoolean("MyBoolean", true);
savedInstanceState.putDouble("myDouble", 1.9);
savedInstanceState.putInt("MyInt", 1);
savedInstanceState.putString("MyString", "Welcome back to Android");
// etc.
}
The Bundle is essentially a way of storing a NVP ("Name-Value Pair") map, and it will get passed in to onCreate()
and also onRestoreInstanceState()
where you would then extract the values from activity like this:
@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
// Restore UI state from the savedInstanceState.
// This bundle has also been passed to onCreate.
boolean myBoolean = savedInstanceState.getBoolean("MyBoolean");
double myDouble = savedInstanceState.getDouble("myDouble");
int myInt = savedInstanceState.getInt("MyInt");
String myString = savedInstanceState.getString("MyString");
}
Or from a fragment.
@Override
public void onViewStateRestored(@Nullable Bundle savedInstanceState) {
super.onViewStateRestored(savedInstanceState);
// Restore UI state from the savedInstanceState.
// This bundle has also been passed to onCreate.
boolean myBoolean = savedInstanceState.getBoolean("MyBoolean");
double myDouble = savedInstanceState.getDouble("myDouble");
int myInt = savedInstanceState.getInt("MyInt");
String myString = savedInstanceState.getString("MyString");
}
You would usually use this technique to store instance values for your application (selections, unsaved text, etc.).
Best Answer
UPDATE
Latest versions introduce
sdkmanager
, a command line tool that allows you to view, install, update, and uninstall packages for the Android SDK.The
sdkmanager
tool is provided in the Android SDK Tools package (25.2.3 and higher) and is located inandroid_sdk/tools/bin/
.so, to update the packages run
to accept the licenses
OLD ANSWER
(Please note: The android command is deprecated!)
The closer you can get to automation probably is:
android provide these options for automatic updates:
If you want to list which packages are available for installation you can use
and you'll obtain an ordered list of packages, for example
Also you can limit the update only to a desired component if you use the
--filter
optionwhere component is one or more of
android list sdk
(i.e. 1, also know as package index)or can be one or more specific identifiers. For instance, if you just want to download a small set of specific packages, you could do this:
and you'll just get the platform tools, api level 16 and support package jar. This is really handy if you're building a build machine only and would have to pay for downloading all the extra stuff that you'll never use.
To see the available options you can use --help, for example