SD card SDcard get external storage directory Android
Environment.getExternalStorageDirectory()+ File.separator
AndroidManifest.xml
Boolean canWrite = Environment.getExternalStorageDirectory().canWrite() ;
if(canWrite){
File f = new File(Environment.getExternalStorageDirectory()
+ File.separator + "my_image.jpg")
f.createNewFile();
}else{
}
AndroidManifest.xml
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
396LW NO topic_id
AD
Další témata ....(Topics)
// warning
private static String DB_PATH = "/data/data/cz.okhelp.german_czech_phrases/databases/";
// OK
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
// OK
DB_PATH = context.getFilesDir().getParentFile().getPath()
+ "/databases/";
}
Canvas, drawCircle(), Paint, onDraw(), setStrokeWidth(), setStyle()
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new SampleView(this));
}
private static class SampleView extends View {
// CONSTRUCTOR
public SampleView(Context context) {
super(context);
setFocusable(true);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.CYAN);
Paint p = new Paint();
// smooths
p.setAntiAlias(true);
p.setColor(Color.RED);
p.setStyle(Paint.Style.STROKE);
p.setStrokeWidth(4.5f);
// opacity
//p.setAlpha(0x80); //
canvas.drawCircle(50, 50, 30, p);
}
}
}
WakeLock, PowerManager,uses-permission Android sample.
Main.java
AndroidManifest.xml
Main.java
public class Main extends Activity {
private SensorManager mSensorManager;
private PowerManager mPowerManager;
private WindowManager mWindowManager;
private WakeLock mWakeLock;
private Button button;
private TextView textView;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
try{
// Get an instance of the SensorManager
mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
// Get an instance of the PowerManager
mPowerManager = (PowerManager) getSystemService(POWER_SERVICE);
// Get an instance of the WindowManager
mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
mWindowManager.getDefaultDisplay();
// Create a bright wake lock
mWakeLock = mPowerManager.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK, getClass()
.getName());
setContentView(R.layout.main);
textView = (TextView)findViewById(R.id.textView1);
button = (Button)findViewById(R.id.button1);
button.setOnClickListener(mButtonStopListener);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("onCreate", e.getMessage());
}
} // END onCreate
View.OnClickListener mButtonStopListener = new OnClickListener() {
public void onClick(View v) {
try {
mWakeLock.release();
textView.setText("mWakeLock.release()");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("onPause",e.getMessage());
}
}
};
@Override
protected void onResume() {
super.onResume();
/*
* when the activity is resumed, we acquire a wake-lock so that the
* screen stays on, since the user will likely not be fiddling with the
* screen or buttons.
*/
try {
mWakeLock.acquire();
textView.setText("mWakeLock.acquire()");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("onResume", e.getMessage());
}
}
@Override
protected void onPause() {
super.onPause();
// and release our wake-lock
try {
mWakeLock.release();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("onPause",e.getMessage());
}
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="//schemas.android.com/apk/res/android"
package="cz.okhelp.Main"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="7" />
<uses-permission android:name="android.permission.HARDWARE_TEST"></uses-permission>
<uses-permission android:name="android.permission.VIBRATE"></uses-permission>
<uses-permission android:name="android.permission.WAKE_LOCK"></uses-permission>
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".ScreenBrightnessActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
float, double is NaN isNaN() isInfinite() Java Android example.
float f = 0.f;
boolean bIsNaN = Float.isNaN(f);
boolean bIsInfinite = Float.isInfinite(f);
double d = Math.sqrt(-10);
boolean b = Double.isNaN(d);
// single line
/*
multi line
*/
Editace: 2013-12-09 10:08:22
Počet článků v kategorii: 396
Url:sd-card-get-external-storage-directory-android