/android_functions_collection

Android Native Application Functions

Primary LanguageHTML

Specifications

Related Android Design Pattern:

  • Factory(Bitmap)
  • Adapter(ListView)
  • Builder(AlertDialog).

Directory:

Screen Layout:

This folder includes Relative Layout Table Layout Linear Layout List View Swipe Views.

  • To apply a layout, follows:

    1. copy the layout.xml to res/layout folder in your project.
    2. Pick the activity java class then modify setContentView(R.layout.your_layout_name).

  • List View (List item value stored in .xml file):

    1. for basic list view: copy all four files in the basic folder seperately to your android project or
    2. create a class extends ListActivity(import related class)
    3. create an XML file for string resources
    4. create an XML file for display each item (type: TextView)
    5. create ArrayAdapter to get the string[]

  • List View (List item value stored in .java file, for activity not extend Listactivity):

    1. create an XML fiel for displaying each list item
    2. create an string array to store value
    3. create an Adapter to connect list value and item layout
    4. create listview and connect it to xml file
    5. setAdapter(listview reference)

  • Be aware of layout_weight.

Staggered GridView(Etsy):

  • Setting up(ADT):
  • Customization/Modification:
    1. TextView aligned on the bottom of layout: android:layout_gravity="bottom"
    2. TextView background transparent with color, for example: android:background="#B3000000", for other opacity refer bottom Reference.
    3. ImageView in XML set scale: android:scaleType="fitXY", fitting xy for example.
  • Ways to set image displayed in app.
    1. The XML way to set image in a layout:
    2. Put image into res->drawable folder
    3. Set android:id="@+id/id-name" & android:src"@drawable/your-file-name" in ImageView component
    4. findViewById() way to set image:
    5. Create an ImageView variable for xml imageview component (import android.widget.ImageView). (Set android:id="@+id/id-name")
    6. variable = (ImageView) findViewById(R.id.id-name), link it.
    7. use imageview variable method setImageResource(R.drawable.your-file-name) to get the image file.

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Icon:

  1. copy icons image seperately to drawable folder under res;
  2. change android:icon="@drawable/your_icon_name in AndroidManifest.xml;

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Splash screen:

  1. for basic splash screen: copy all three files into different folders in your project or
  2. create a handler and also use its Handler().postDelayed(new Runnable(), SPLASH_DISPLAY_LENGTH)
  3. Override run() method.
  4. full screen: add android:theme="@android:style/Theme.NoTitleBar.Fullscreen" to AndroidManifest.xml.
  5. (Optional for splash screen) add android:screenOrientation="portrait"android:theme="@android:style/Theme.Black.NoTitleBar", this will let the splash screen with a status bar and perform perfect sa far.

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Alert Dialog:

  1. (Skip step) For the fluent UI and hold the main UI thread runs without clogging, we could set up a new worker thread to finish the job. new a handler, new a runnable and override the run() method.
  2. new AlertDialog inside the block and set the its builder for the specific activity.
  3. setTitle(), setMessage(), setCancelable(boolean), setNegativeButton("string",Override OnClickListenr() method).
  4. call the .create() and .show() method.

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Navgation bar listening:

= onSaveInstanceState = onUserLeaveHint = ACTION_CLOSE_SYSTEM_DIALOGS = Framework PhoneWindowManager.java

Debug:

  1. Using logcat to debug:
  2. create log class then using its d method to pass the tag and message.
  3. Using toast to test: Toast.makeText(context, message, duration).show();, for the context arguement I would like to use this for current class.

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Reference:

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http://stackoverflow.com/questions/15852122/hex-transparency-in-colors

Hex Values Opacity
100% — FF
95% — F2
90% — E6
85% — D9
80% — CC
75% — BF
70% — B3
65% — A6
60% — 99
55% — 8C
50% — 80
45% — 73
40% — 66
35% — 59
30% — 4D
25% — 40
20% — 33
15% — 26
10% — 1A
5% — 0D
0% — 00