The Learning Path of Android (iv) Study of inventory files in the project and common display units in Android

1. The so-called manifest file is the Androidmanifest.xml file in the project, which is of great use, such as: The name of the app, the icon, the package name of the app-supported version of the app, and so on. Let me introduce the various parameters of this manifest file.

<manifest xmlns:android= "http://schemas.android.com/apk/res/android" namespace  package= "Com.example.hello" Package name uniquely identifies an app android:versioncode= "1" version number    android:versionname= "1.0" version name   android:icon= "@drawable/ic_launcher The app icon. To access the Drawable constants of the R.java file, use the icon's ic_launcher under this constant as the app icons  android:label= "@string/app_name" app name < Activity has multiple activity in an application. An activity represents a window            android:name= "com.example.hello.MainActivity" This package Com.example.hello under the Mainactivity            Android:label= the title <intent-filter> Intent filter of the "@string/app_name" >activity window            specifically matches the intent to filter the data                <action Android:name= "Android.intent.action.MAIN"/> Action name                <category android:name= " Android.intent.category.LAUNCHER "/>            </intent-filter>  </activity>   android: Minsdkversion= "8" specifies the lowest version supported by the app        android:targetsdkversion= "/>" the highest version

Display units in 2.android

1..PX (pixels) The general HVGA represents 320*480 pixels, which is used more
2..dip or DP (device independent pixels), this is related to the device hardware, generally in order to support WVGA,QVGA and HVGA recommended to use this, do not rely on pixels
3..SP (proportional pixels) primarily handles the size of the font and can be adapted to the font of the system.
In addition to the above 3, there are several less commonly used, in (feet), mm (mm), pt (point) 1/72 inch
In order to adapt to different resolutions, different pixel densities, it is recommended to use Dip, text using SP,