Get Context Java Android example
getContext() getApplicationContext() method Java Android example source
Context myContext_1 = ThisClassName.this; // to open a Dialog
Context myContext_2 = getContext();
Context myContext_3 = this.getContext();
Context myContext_4 = this;
Context myContext_5 = this.getApplicationContext ();
OnClickListener getImageBtnOnClick = new OnClickListener() {
public void onClick(View view) {
Context context = view.getContext();
}
};
// Toast
Toast.makeText(getApplicationContext(), "Context == getApplicationContext "
, Toast.LENGTH_SHORT).show();
// store Context in public class
public class MyActivity extends Activity {
public static Context myCnt = null;
...
protected void onCreate(Bundle icicle) {
...
myCnt = this;
MyStorage.setContext(myCnt);
// or
// MyStorage.setContext(this);
// cntxFromStorage == this
Context cntxFromStorage = MyStorage.getContext();
...
};
};
public class MyStorage
{
private static Context cntStorageContext = null;
public static Context getContext() {
return cntStorageContext;
}
public static void setContext(Context context) {
MyStorage.cntStorageContext = context;
}
};
class DataBaseHelper extends SQLiteOpenHelper {
// get MyActivity context
Context cnt = MyStorage.getContext();
}
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I You use offline work for better building speed of project or for other purpose
https://gradle.org/releases
Offline work:
File - Settings - Gradle
- select Use local gradle distribution
- select path Gradle home:
- check Offline work
https://gradle.org/releases
Offline work:
File - Settings - Gradle
- select Use local gradle distribution
- select path Gradle home:
- check Offline work
Android development
long is 64 bit signed type and used when int is not large enough to hold the value.
long je celé číslo 64 bitů -9223372036854775808 +9223372036854775807 a používá se tam, kde typ int není schopen pojmout takovou hodnotu čísla.
long is 64 bit signed type and used when int is not large enough to hold the value.
long je celé číslo 64 bitů -9223372036854775808 +9223372036854775807 a používá se tam, kde typ int není schopen pojmout takovou hodnotu čísla.
// declaration and assignment of value type long
long n = 22337203685477580L;
// print formated value
System.out.printf("The value of x is %d%n", n); // 22337203685477580
System.out.format("%+,8d%n%n", n); // +22 337 203 685 477 580
// declaring more variables in single statement
long lo1 = 12L, lo2 = 56, lo3 = 1455555555589L;
// long range of value
System.out.println(Long.MAX_VALUE); // 9223372036854775807
System.out.println(Long.MIN_VALUE); // -9223372036854775808
// check if a string is a valid number in Java example
// convert string to long Java example
String sLong = "1288888888888888";
long longParse = Long.parseLong(sLong);
// convert strings to numbers
long longFromString = (Long.valueOf(sLong)).longValue();
// long to string in Java example code
Long longObj = new Long(229999999999L);
String str = longObj.toString();
// else
Long longS = 888888888888L;
String strLong = longS.toString();
// compare two long variables
Long longComp1 = 5555L;
if (longComp1.equals(55555555L))
System.out.print("true");
// compares the two specified long values in Java example
int i = longS.compareTo(444444L); // -1 first < second
// 0 first == second
// 1 first > second
System.out.print(i);
Issue: Cropped superscript index between tags sup /sup is not correctly visible in TextView or View as Button.

String s = "10<sup>12 </sup>";
textView.setText(Html.fromHtml(s)); // 12 will cropped
// solution:
s = "10<sup>12 </sup>\t "; // add behind ending of sup tag the tabulator \t,
// but not char \t but only press to TAB key!!! in source code
textView.setText(Html.fromHtml(s)); // 12 is visible correctly

putString(), putBoolean(), putInt() etc.¨
How we can start an activity programmatically.
How we can start an activity programmatically.
// MainActivity.java
// myButton.setOnClickListener
Intent binary = new Intent(getApplicationContext(),Calculate.class);
Bundle b = new Bundle();
b.putString("prvni_label", "Decimal");
b.putString("druhy_label", "Binary");
b.putString("mode", "binary_to_decimal");
binary.putExtras(b);
startActivityForResult(binary, 0);
// in Calculate.java onCreate
TextView mTextView1 = (TextView)findViewById(R.id.textView1);
TextView mTextView2 = (TextView)findViewById(R.id.textView2);
Bundle _bundle = getIntent().getExtras();
mTextView1.setText(_bundle.getString("prvni_label"));
mTextView2.setText(_bundle.getString("druhy_label"));
//.................. HOW OPEN START NEW ACTIVITY WITHOUT A PARAMETER .........................
startActivity(new Intent(ThisActivity.this, NewActivity.class));
Editace: 2011-10-15 08:31:19
Počet článků v kategorii: 396
Url:get-context-java-android-example