Android code block

1. Obtain the System Version Number:

PackageInfo info = this. getPackageManager (). getPackageInfo (this. getPackageName (), 0 );

Int versionCode = info. versionCode

String versionName = info. versionNam

2. Obtain system information:

String archiveFilePath = "sdcard/download/Law.apk"; // installation package path

PackageManager pm = getPackageManager ();

PackageInfo info = pm. getPackageArchiveInfo (archiveFilePath, PackageManager. GET_ACTIVITIES );

If (info! = Null ){

ApplicationInfo appInfo = info. applicationInfo;

String appName = pm. getApplicationLabel (appInfo). toString ();

String packageName = appInfo. packageName; // obtain the installation package name.

String version = info. versionName; // obtain the version information.

Toast. makeText (test4.this, "packageName:" + packageName + "; version:" + version, Toast. LENGTH_LONG). show ();

Drawable icon = pm. getApplicationIcon (appInfo); // get the icon Information

TextView TV = (TextView) findViewById (R. id. TV); // display icon

TV. setBackgroundDrawable (icon );
3. Obtain the installation path and list of installed programs

(1) obtain the current program path in android

GetApplicationContext (). getFilesDir (). getAbsolutePath ()

(2) android app list

List PackageInfoList = getPackageManager (). getInstalledPackages (0 );
4. Image Retrieval, application name, and package name

PackageManager pManager = MessageSendActivity. this. getPackageManager ();

List AppList = Utils. getAllApps (MessageSendActivity. this );

For (int I = 0; I

PackageInfo pinfo = appList. get (I );

Required iteminfo items item = new required iteminfo ();

// Set Icon

Using item. setIcon (pManager. getApplicationIcon (pinfo. applicationInfo ));
5. solve the problem that the Item itself cannot be clicked when there is a button on the item on the listview:

1. Add the code android: descendantFocusability = "blocksDescendants" to the item Attempt"

2. Add the code android: focusable = "true" to listview"

6. Do not enter Chinese characters in the text box:

Android: digits = "1234567890qwertyuiopasdfghjklzxcvbnm '-= [] \;,./~! @ # $ % ^ * () _ + }{:? & <> "'" Does not input Chinese characters.
7. Obtain the screen width and height
DisplayMetrics displayMetrics = new DisplayMetrics ();

This. getWindowManager (). getdefadisplay display (). getMetrics (displayMetrics );

Int height = displayMetrics. heightPixels;

Int width = displayMetrics. widthPixels;
8. Obtain the device model, SDK version, and system version.
String device_model = Build. MODEL; // Device MODEL

String version_sdk = Build. VERSION. SDK; // the sdk version of the device.

String version_release = Build. VERSION. RELEASE; // system VERSION of the device
9. obtain all the activities under the application.
Public static ArrayList GetActivities (Context ctx ){

ArrayList Result = new ArrayList ();

Intent intent = new Intent (Intent. ACTION_MAIN, null );

Intent. setPackage (ctx. getPackageName ());

For (ResolveInfo info: ctx. getPackageManager (). queryIntentActivities (intent, 0 )){

Result. add (info. activityInfo. name );

}

Return result;

}