Draw drawARGB() Android basic example
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) {
//drawARGB (int a, int r, int g, int b)
// a alpha component (0..255) of the color to draw onto the canvas
// r red component (0..255)
// g green component (0..255)
// b blue component (0..255)
canvas.drawARGB(255, 0, 255, 10);
}
}
}
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Další témata ....(Topics)
Convert number int to string Android Java example source code.
int n = 0;
try {
n = Integer.parseInt("21"));
} catch(NumberFormatException e) {
System.out.println("Could not parse " + e);
}
// int to string
String s = String.valueOf(24);
choreographer skipped frames
Create filter with TAG regex to disable Choreographer messages, see code and picture below:

Create filter with TAG regex to disable Choreographer messages, see code and picture below:
^((?!Choreographer).)*$

Try this trick.
In AndroidManifest - activity tag write this code
App hold data of a views if will to rotation of device.
In AndroidManifest - activity tag write this code
android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"
App hold data of a views if will to rotation of device.
<activity
android:name=".Tests_Activity"
android:label="@string/app_name"
android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize" />
Log.e println needs a message error.
E/AndroidRuntime(330): FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{b.paint/b.paint.MainActivity}: java.lang.NullPointerException: println needs a message
Try this code:
E/AndroidRuntime(330): FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{b.paint/b.paint.MainActivity}: java.lang.NullPointerException: println needs a message
Try this code:
// Error
String s = null;
Log.e("bla", s); // !!! error Log.e println needs a message error.
// OK
String s = null;
Log.e("bla", s+""); // OK
StringBuilder, res/raw folder, try catch finaly throws, BufferedReader, InputStream, openRawResource, getResources Android example
MainActivity.java
MainActivity.java
public class MainActivity extends Activity {
TextView txtV;
Context cntx;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
txtV = (TextView)findViewById(R.id.idLabel);
cntx = this;
try {
StringBuilder strBuilder = myFunction(cntx);
txtV.setText(strBuilder);
} catch (IOException e) {
e.printStackTrace();
}
}
private StringBuilder myFunction(Context context) throws IOException {
final Resources resources = context.getResources();
InputStream inputStream = resources.openRawResource(R.raw.my_file);
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder strBuild = new StringBuilder();
try {
String line;
while ((line = reader.readLine()) != null) {
strBuild.append(line);
}
} finally {
reader.close();
}
return strBuild;
}
}
Editace: 2013-12-09 13:10:51
Počet článků v kategorii: 396
Url:draw-drawargb-android-basic-example