擷取螢幕解析度，透過 getResource()

透過 getResource()方法傳回一個Resource 物件，再用Resource 物件中的getDisplayMetrics()
傳回DisplayMetrics(

package com.example.mygraphics;

import android.app.Activity;
import android.content.res.Resources;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {
private TextView tv;
private Resources res;
DisplayMetrics metrics;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv=(TextView)findViewById(R.id.tv);
res=getResources();
metrics=res.getDisplayMetrics();
}

@Override
protected void onStart() {
// TODO Auto-generated method stub
super.onStart();
tv.setText("寬"+metrics.widthPixels+"\n");
tv.append("長"+metrics.heightPixels+"\n");
tv.append("DPI"+metrics.densityDpi);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}

}