android - How to get screen density

activity_main.xml 
 <RelativeLayout     xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:id="@+id/rl"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:padding="10dp"     tools:context=".MainActivity"     android:background="#eddf00"     android:animateLayoutChanges="true"     >     <TextView         android:id="@+id/tv"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:fontFamily="Sans-Serif-Condensed"         android:textSize="18dp"         android:textStyle="italic"         android:textColor="#000000"         android:padding="15dp"         />     <Button         android:id="@+id/btn"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="Get Screen Density"         android:layout_below="@id/tv"         /> </RelativeLayout>
MainActivity.java 
 package com.cfsuman.me.androidcodesnippets;  import android.app.ActionBar; import android.graphics.Color; import android.graphics.drawable.ColorDrawable; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.widget.Button; import android.widget.RelativeLayout; import android.widget.TextView; import android.util.DisplayMetrics; import android.content.Context; import android.view.WindowManager;   public class MainActivity extends Activity {      protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);          // Get the widgets reference from XML layout         simpulan RelativeLayout rl = (RelativeLayout) findViewById(R.id.rl);         simpulan Button btn = (Button) findViewById(R.id.btn);         simpulan TextView tv = (TextView) findViewById(R.id.tv);          ActionBar ab = getActionBar();         ab.setBackgroundDrawable(new ColorDrawable(Color.RED));          btn.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                 /*                     Context                         Interface to global information about an application environment.                         This is an abstract class whose implementation is provided by the                         Android system. It allows access to application-specific resources                         and classes, as well as up-calls for application-level operations                         such as launching activities, broadcasting and receiving intents, etc.                 */                  // Get the application context                 Context context = getApplicationContext();                  // Get the activity                 Activity activity = MainActivity.this;                  tv.setText("Screen density from activity : "                         + getScreenDensity(activity));                 tv.setText(tv.getText() + "\nScreen density from context : "                         + getScreenDensityFromContext(context));            }         });     }      // Custom method to get screen density using activity     public static float getScreenDensity(Activity activity){         /*             DisplayMetrics                 A structure describing general information about a display,                 such as its size, density, and font scaling.         */         DisplayMetrics dm = new DisplayMetrics();          /*             WindowManager                 The interface that apps use to talk to the window manager.                 Use Context.getSystemService(Context.WINDOW_SERVICE) to get one of these.         */          /*             public abstract Display getDefaultDisplay ()                  Returns the Display upon which this WindowManager instance will create new windows.                  Returns                 The display that this window manager is managing.         */          /*             public void getMetrics (DisplayMetrics outMetrics)                 Gets display metrics that describe the size and density of this display.                 The size is adjusted based on the current rotation of the display.                  Parameters                 outMetrics A DisplayMetrics object to receive the metrics.         */         activity.getWindowManager().getDefaultDisplay().getMetrics(dm);         /*             public float density              The logical density of the display.         */         float density = dm.density;         return density;     }      // Custom method to get screen density using Context object     public static float getScreenDensityFromContext(Context context){         DisplayMetrics dm = new DisplayMetrics();         WindowManager windowManager = (WindowManager) context.getSystemService(WINDOW_SERVICE);         windowManager.getDefaultDisplay().getMetrics(dm);         /*             public float density                 The logical density of the display. This is a scaling factor for the Density                 Independent Pixel unit, where one DIP is one pixel on an approximately                 160 dpi screen (for example a 240x320, 1.5"x2" screen), providing                 the baseline of the system's display. Thus on a 160dpi screen this                 density value will be 1; on a 120 dpi screen it would be .75; etc.         */         float density = dm.density;         return density;     } }
More android examples

Komentar

Posting Komentar