I want to use getWindowManager() in my MainActivity, but I don’t want to write this method directly in it.
Here is my MainActivity code
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String d= new DisplayMessageActivity().getWeithAndHeight(d);
}
and here is my DisplayMessageActivity code
public class DisplayMessageActivity extends Activity {
@SuppressLint("NewApi")
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Intent intent = getIntent();
....
....
setContentView(textView);
}
public String getWeithAndHeight(String url) {
DisplayMetrics dm = new DisplayMetrics();
*getWindowManager().getDefaultDisplay().getMetrics(dm);*
int width = dm.widthPixels;
int height = dm.heightPixels;
String w=new String(""+width);
String h=new String(""+height);
url=url+"&23=w%3A"+w+"%20h%3A"+h+"%20d%3A";
return url;
}
}
my code break at getWindowManager(), please tell me why. Thank you very much.
public String getWeithAndHeight(Context context, String url) {
DisplayMetrics dm = new DisplayMetrics();
((Activity)context).getWindowManager().getDefaultDisplay().getMetrics(dm);
//....
}
Answer：
Why don’t you create static method:
public static String getWeithAndHeight(Activity activity, String url) {
DisplayMetrics dm = new DisplayMetrics();
activity.getWindowManager().getDefaultDisplay().getMetrics(dm);
int width = dm.widthPixels;
int height = dm.heightPixels;
String w=new String(""+width);
String h=new String(""+height);
url=url+"&23=w%3A"+w+"%20h%3A"+h+"%20d%3A";
return url;
}
Your DisplayMessageActivity is not created successuffly. You cannot just create new activity object to use all of its methods.
Answer：
Way too late to the party here, posting the answer as someone might be able to benefit from it. you can get WindowManager()as a static reference using the context like this.
DisplayMetrics displayMetrics = new DisplayMetrics();
WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
if (windowManager != null) {
windowManager.getDefaultDisplay().getMetrics(displayMetrics);
}
now you can use display matrix to get width,height etc
Answer：
Answer of your first question “I want to use getWindowManager() in my MainActivity, but I don’t want to write this method directly in it.” You can write BaseActivity extends Activity & here you can define the code for
public String getWeithAndHeight(Context context, String url) {
DisplayMetrics dm = new DisplayMetrics();
((Activity)context).getWindowManager().getDefaultDisplay().getMetrics(dm);
//....
}
And for DisplayMessageActivity & MainActivity you can extends with BaseActivity.
Answer：
Follow two steps:
First:
extend Activity class
class Example extends Activity
Second: Use these lines
DisplayMetrics displayMetrics = new DisplayMetrics();
WindowManager windowmanager = (WindowManager)getApplicationContext().getSystemService(Context.WINDOW_SERVICE);
windowmanager.getDefaultDisplay().getMetrics(displayMetrics);
int deviceWidth = displayMetrics.widthPixels;
int deviceHeight = displayMetrics.heightPixels;
Answer：
If you are using Kotlin, this code might be helpful to you:
private fun getDeviceWidthAndHeight() {
val metrics = DisplayMetrics()
val windowManager = context.getSystemService(Context.WINDOW_SERVICE) as WindowManager
windowManager?.defaultDisplay?.getMetrics(metrics)
viewWidth = metrics.widthPixels
viewHeight = metrics.heightPixels
}
Tags: android, androidjava, file
