action bar上的up button

up button 和 back button的比較:
up:  回到前一頁或是某個頁面
back:  回上一步，比方收起鍵盤

顯示up button

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        ActionBar actionBar = getActionBar();
        actionBar.setDisplayHomeAsUpEnabled(true);
     
}


判斷up button 被點選

public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    // Respond to the action bar's Up/Home button
    case android.R.id.home:
          this.finish();
        return true;
    }
    return super.onOptionsItemSelected(item);
}

設定編碼UTF8

讓EditText的cursor color等於文字顏色

設定  textCursorDrawable

  <EditText
    android:layout_width="30dp"
    android:layout_height="44dp"
    android:textColor="#000000"
   
    android:textSize="14sp"
     android:paddingLeft="6dp"
     android:textCursorDrawable="@null"
   
    />
   

delete file

ex:
     
                File file = new File(context.getFilesDir(), "plan.txt");

try {
file.getCanonicalFile().delete();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

back多層activity

ex:

A ->  B -  > C
想要從C返回A


C.java:


Intent intent = new Intent(this, A.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);

AndroidManifest.xml:


 <activity
            android:name="com.passionbean.fitmi.A"
            android:label="@string/app_name"
            android:screenOrientation="portrait"
            android:launchMode="singleTask" 
            >
           
        </activity>

回到桌面(home)

moveTaskToBack(true);

防止back鍵作用

   public boolean onKeyDown(int keyCode, KeyEvent event) {
       if (keyCode == KeyEvent.KEYCODE_BACK ) {
           /*
            * Use this hook instead of onBackPressed(), because onBackPressed()
            * is not available in API 4.
            */
           return true;
       }

       return super.onKeyDown(keyCode, event);
   }// onKeyDown()

設定action bar的title

XML:

利用android:label

ex:

  <activity
            android:name=".RegisterActivity"
            android:label="註冊新帳號"
            android:screenOrientation="portrait"
                        android:windowSoftInputMode="stateHidden"
             >


JAVA:


  ActionBar ab = getActionBar();
  ab.setTitle("My Title");

讀檔產生圖片Bitmap

File storageDir = new File(
       Environment.getExternalStoragePublicDirectory(
           Environment.DIRECTORY_PICTURES
       ),
       "FitMi"
    );
File imageFile = new File(storageDir.getPath(), "test.jpg");
Bitmap bitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath());

存取專案裡assets下的檔案

ex:

AssetManager assetManager = getAssets();


try {
            InputStream input = assetManager.open("Message.plist");


} catch (Exception e) {

e.printStackTrace();
}

當按下enter時收起鍵盤

   EditText nameEditText = (EditText)this.findViewById(R.id.editBasicNameEditText);
       
       
        OnKeyListener keyboardListener = new OnKeyListener()
        {
            /**
             * This listens for the user to press the enter button on
             * the keyboard and then hides the virtual keyboard
             */
        public boolean onKey(View arg0, int arg1, KeyEvent event) {
               // If the event is a key-down event on the "enter" button
               if ( (event.getAction() == KeyEvent.ACTION_DOWN  ) &&
                    (arg1 == KeyEvent.KEYCODE_ENTER)   )
               {              
                InputMethodManager imm = (InputMethodManager)getSystemService(INPUT_METHOD_SERVICE);
                       imm.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY, 0);  
                       return true;
               }
               return false;
            }
       } ;
       
nameEditText.setOnKeyListener(keyboardListener);

AChartEngine

http://code.google.com/p/achartengine/

1. 在折線圖上顯示出每個點的值


((XYSeriesRenderer) renderer.getSeriesRendererAt(0)).setDisplayChartValues(true);

2.  not show legend item


     ((XYSeriesRenderer) renderer.getSeriesRendererAt(0)).setShowLegendItem(false);

hide 紅色圈起的部分

3. 改變X, Y軸上label的color

ex:

   renderer.setYLabelsColor(0, Color.BLACK);

4. 設定線條顏色

            int[] colors = new int[] {  Color.rgb(30, 155, 165)};
   PointStyle[] styles = new PointStyle[] { PointStyle.CIRCLE };
  renderer = buildRenderer(colors, styles);

5. 設定線條粗細

 renderer = buildRenderer(colors, styles);
   int length = renderer.getSeriesRendererCount();
   for (int i = 0; i < length; i++) {
     XYSeriesRenderer seriesRenderer  = ((XYSeriesRenderer)  renderer.getSeriesRendererAt(i));

     seriesRenderer.setLineWidth(3f);


   }

6. 設定point

   renderer.setPointSize(10);

write & read object to file by Serializable

ex:

public class FitPlan implements Serializable {

public long startDateNumber;
public long endDateNumber;
public float targetWeight;
public float startWeight;
public String name;
public int calorieQuota;
public int bmr;
public float workPercentage;
public String uuid;


       public void writeToFile(Context context)
{
File file = new File(context.getFilesDir(), "plan.txt");
try {
FileOutputStream fos = new FileOutputStream(file);
ObjectOutputStream oos = new ObjectOutputStream(fos);            
oos.writeObject(this);
oos.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

public static FitPlan createFromFile(Context context)
{
File file = new File(context.getFilesDir(), "plan.txt");
FitPlan plan = null;

try{
FileInputStream fis = new FileInputStream(file);
ObjectInputStream in = new ObjectInputStream(fis);            

plan = (FitPlan) in.readObject();

in.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

return plan;
}

}

說明
FitPlan的每個欄位也都必須是Serializable，才能寫入檔案。
不想寫入檔案的欄位，可加上transient

取得前一天/後一天的時間

currentDate的類別是Time

void preDay() {
this.currentDate.monthDay -= 1;
this.currentDate.normalize(true);

}


void nextDay() {
 this.currentDate.monthDay += 1;
 this.currentDate.normalize(true);

}

apk

路徑:

bin/xxx.apk

執行App後，才會產生新的apk

從Finder打開檔案

1. 設定External Tools Configuration

2. 新增打開Finder的指令

輸入Location : /usr/bin/open
       Arguments:  ${container_loc}

3. 點選檔案

4. 點選finder

取得screen的大小

        DisplayMetrics displaymetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
        int width = displaymetrics.widthPixels;
        int height = displaymetrics.heightPixels;

設定action bar的title color

ex


   <style name="MyTitleTextStyle" parent="@android:style/TextAppearance">
    <item name="android:textColor">#000000</item>
  </style>
 
    <style name="MyActionBar" parent="android:Widget.Holo.ActionBar">
  <item name="android:background">@android:color/transparent</item>
     <item name="android:titleTextStyle">@style/MyTitleTextStyle</item>
 
</style>
   
    <style name="FitMiTheme" parent="@android:style/Theme.Holo">
          <item name="android:windowActionBarOverlay">true</item>
       <item name="android:actionMenuTextColor">#0000ff</item>
      <item name="android:actionBarStyle">@style/MyActionBar</item>
             
    </style>

設定action bar上button icon

<menu xmlns:android="http://schemas.android.com/apk/res/android" >

    <item
        android:id="@+id/action_settings"
        android:showAsAction="always"
        android:icon="@drawable/setting"/>

</menu>

移除action bar divider

ex:

 <style name="MyActionBar" parent="android:Widget.Holo.ActionBar">
  <item name="android:background">@android:color/transparent</item>
</style>
   
    <style name="FitMiTheme" parent="@android:style/Theme.Holo">
          <item name="android:windowActionBarOverlay">true</item>
       <item name="android:actionMenuTextColor">#0000ff</item>
         <item name="android:actionBarStyle">@style/MyActionBar</item>
             
    </style>

App設計教學文章

Android cheatsheet for graphic designers

Designing For Android

write bitmap to file

ex:
File imageFile; 
Bitmap bitmap;
FileOutputStream out = new FileOutputStream(imageFile);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);

save file in external storage

1. 設定權限 in AndroidManifest.xml


<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.passionbean.fitmi"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="11"
        android:targetSdkVersion="17" />
 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

    <application
        android:allowBackup="true"

2.  建立file


File albumDir = new File(
   Environment.getExternalStoragePublicDirectory(
       Environment.DIRECTORY_PICTURES
   ),
   "FitMi"
);


if(albumDir.exists() == false)
{
albumDir.mkdir();

}

File imageFile = new File(albumDir.getPath(), "test.jpg");

camera使用

http://developer.android.com/training/camera/photobasics.html

AlertDialog的使用

ex:


AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
     AddFoodActivity.this);
   
alertDialogBuilder.setTitle("選擇來源");
   
 
alertDialogBuilder.setCancelable(true)
    .setPositiveButton("拍照",new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog,int id) {
    // if this button is clicked, close
    // current activity
    Intent i = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    startActivityForResult(i, CAPTURE_IMAGE_ACTIVITY_REQ );
    }
     })
    .setNeutralButton("相簿",new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog,int id) {
    // if this button is clicked, just close
    // the dialog box and do nothing
    Intent i = new Intent(Intent.ACTION_GET_CONTENT);
    i.setType("image/*");
    startActivityForResult(i, ALBUM_IMAGE_ACTIVITY_REQ );
    }
    })
    .setNegativeButton("取消", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog,int id) {
    // if this button is clicked, just close
    // the dialog box and do nothing
    dialog.cancel();
    }
    });
   
AlertDialog alertDialog = alertDialogBuilder.create();
   
alertDialog.show();

建立list單選的dialog:


final CharSequence[] items = {"靜態活動(大部份時間都坐著)", "輕度活動(每天散步的人)", "中度活動(每天做劇烈運動的人)",
"重度活動(參與每日體育訓練的人)" };

AlertDialog.Builder builder = new AlertDialog.Builder(this);
     

builder.setTitle("工作活動量")
          .setItems(items, new DialogInterface.OnClickListener() {
              public void onClick(DialogInterface dialog, int which) {
              // The 'which' argument contains the index position
              // of the selected item
             
          }
   });
AlertDialog alertDialog = builder.create();
alertDialog.show();

ViewPager的使用

建立頁面UI元件

public Object instantiateItem(View container, int position)

delete頁面UI元件
public void destroyItem(View arg0, int arg1, Object arg2)

更新ViewPager

ex:
ImageAdapter adapter = (ImageAdapter)viewPager.getAdapter();
viewPager.setAdapter (null);
viewPager.setCurrentItem(newIndex);
viewPager.setAdapter (adapter);

dp轉pixel

ex:

 int height = (int)TypedValue.applyDimension(
               TypedValue.COMPLEX_UNIT_DIP, 1, getResources().getDisplayMetrics());


當程式或XML裡設定單位為dp時，對應的pixel計算範例:
10 dp:
MDPI : 10 pixel
HDPI:   15 pixel
XHDPI:  20 pixel

文字置中

ex:

dateTextView.setGravity(Gravity.CENTER_HORIZONTAL);

UI文字設定 (font)

XML:
ex:


<Button
           android:id="@+id/addFoodCategoryBreakfastButton"
    android:layout_width="80dp"
    android:layout_height="30dp"
    android:layout_marginTop="10dp"
    android:layout_marginLeft="10dp"
    android:text="早餐"
     android:textColor="#000000"

android:textSize="12sp"

    android:background="@drawable/roundcornerforaddfoodcategorybutton"
    />

設定圓角

1. 新增設定圓角圖形的XML在res/drawable下

ex: 新增roundcorner.xml


<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

<corners android:radius="8dp" />

<solid android:color="#7fc7b299" />

</shape>

ex:


<corners android:bottomRightRadius="8dp" android:bottomLeftRadius="8dp"
     android:topLeftRadius="0dp" android:topRightRadius="0dp"/>


說明:
solid欄位設定圖形的背景顏色

2.  在layout的xml指定background為roundcorner

ex:


<View
           android:id="@+id/addFoodCategoryBackground"
    android:layout_width="100dp"
    android:layout_height="100dp"
    android:layout_marginTop="10dp"
    android:layout_marginLeft="10dp"
     android:layout_below="@+id/addFoodDateTitleImageView"
    android:layout_toRightOf="@+id/addFoodPhotoButton"
    android:background="@drawable/roundCorner"
    />
       

防止鍵盤因為ScrollView上有EditText而自動彈出

修改AndroidManifest.xml，於scroll view對應的activity裡設定windowSoftInputMode

ex:

         <activity
            android:name=".AddFoodActivity"
            android:label="@string/app_name"
            android:windowSoftInputMode="stateHidden" >
         
        </activity>

防止表格over scroll時出現藍色線條

listView.setOverScrollMode(View.OVER_SCROLL_NEVER);

基本表格操作

透過ListView顯示表格

1. 新增xml，定義ListView

2. 新增xml，定義表格裡每一行的UI

3. 新增繼承自ArrayAdapter的類別 (.java)
    定義getView method。此method將回傳表格每一行的UI

4. 在activity的程式碼裡設定listView的adapter


設定cell的高度
由定義表格裡每一行UI的XML的layout_height決定

更新表格內容
ex:
 dataListView.invalidateViews();

UI元件的隱藏

設定
呼叫setVisibility
Parameters
visibility One of VISIBLE, INVISIBLE, or GONE.

判斷是否隱藏
呼叫isShown

字串和數字的轉換

 int count = Integer.parseInt("100");

float value = Float.parseFloat("100.33");

產生UUID

String uniqueID = UUID.randomUUID().toString();

設定action bar

XML

<menu xmlns:android="http://schemas.android.com/apk/res/android" >

    <item
        android:id="@+id/action_done"
        android:showAsAction="always"
        android:title="完成"
        />
</menu>

JAVA
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu items for use in the action bar
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.done, menu);
    return super.onCreateOptionsMenu(menu);
}

button被點選

public boolean onOptionsItemSelected(MenuItem item) {

   

return true;

}

設定透明顏色

XML:

   <ImageButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_toRightOf="@+id/addFecesDiarrheaButton"
    android:layout_alignBottom="@+id/addFecesCountLabel"
    android:src="@drawable/irregularity"
    android:background="@android:color/transparent"
    />

JAVA:


    addFoodButton.setBackgroundColor(Color.TRANSPARENT);

利用picker設定日期和時間

ex:


   dateButton.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
DatePickerDialog dialog = new DatePickerDialog(AddFecesActivity.this, new DatePickerDialog.OnDateSetListener() {

@Override
public void onDateSet(DatePicker view, int year, int monthOfYear,
int dayOfMonth) {
// TODO Auto-generated method stub
  currentTime.set(0, currentTime.minute, currentTime.hour, dayOfMonth,
monthOfYear,year);
  String timeStr = currentTime.format("%Y-%m-%d");
      dateButton.setText(timeStr);
}
}, currentTime.year, currentTime.month, currentTime.monthDay);
dialog.show();
}
});
     
 
     
       timeButton.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub

TimePickerDialog dialog = new TimePickerDialog(AddFecesActivity.this, new TimePickerDialog.OnTimeSetListener(){
@Override
   public void onTimeSet(TimePicker view, int hourOfDay, int minute) {

currentTime.set(0, minute, hourOfDay, currentTime.monthDay,
currentTime.month+1, currentTime.year);
  String timeStr = currentTime.format("%H:%M");
      timeButton.setText(timeStr);
     
   }

}, currentTime.hour, currentTime.minute,
false);

dialog.show();

}
});

時間轉字串

ex:


Time time = new Time();
time.setToNow();
String str = time.format("%Y-%m-%d %H:%M");


->

2013-08-27 11:31

取得目前時間

Time time = new Time();
time.setToNow();

XML Drawables

Layer List
State List
Level List
TransitionDrawable
InsetDrawable
ClipDrawable
ScaleDrawable
ShapeDrawable

http://www.vogella.com/articles/AndroidDrawables/article.html

9-patch image

http://radleymarx.com/blog/simple-guide-to-9-patch/

http://www.ootpapps.com/2013/02/android-9-patch-imageshow-they-work-and-how-to-create-them/

draw 9 patch image

draw9patch

density

 For example, you might decide that your default padding is going to be 16px for XHDPI. That means it will be 12px for HDPI and 8px for MDPI (which is also 8dp). Approach your design with the 2:3:4 ratio in mind; that’s the ratio of MDPI pixels to HDPI pixels to XHDPI pixels

fragment

A Fragment represents a behavior or a portion of user interface in an Activity. You can combine multiple fragments in a single activity to build a multi-pane UI and reuse a fragment in multiple activities. You can think of a fragment as a modular section of an activity, which has its own lifecycle, receives its own input events, and which you can add or remove while the activity is running (sort of like a "sub activity" that you can reuse in different activities).

AdapterView

You have a data set, you throw it at an Adapter, and you end up with views in your layout

ex:

ListView

ExpandableListView

group list data by categories. It has the capability of expanding and collapsing the groups when user touches header.

GridView

Spinner

ViewPager

Adapter is the interface that takes a data set and returns views representing that data. The adapter is able to say how many items there are, return an item for a specific position, and return the view associated with a position, among other things. For a ListView, you will use the ListAdapter interface that extends Adapter to add a couple of list-specific methods. Similarly, you will use the SpinnerAdapter interface for use in a Spinner.

gravity and layout_gravity

android:gravity sets the gravity of the content of the View its used on.
android:layout_gravity sets the gravity of the View or Layout in its parent.

ex:

<Button
           android:id="@+id/addFoodDateButton"
    android:layout_width="140dp"
    android:layout_height="40dp"
    android:layout_marginTop="12dp"
    android:layout_marginLeft="12dp"
    android:textColor="#000000"
     android:background="@android:color/transparent"
     android:layout_toRightOf="@id/addFoodDateTitleImageView"
     android:text="2013-09-12"
     android:gravity="left|center_vertical"      
    />




android:gravity
center_vertical, top , bottom

ex:


calorieTextView.setGravity(Gravity.CENTER);

ViewGroup

the ViewGroup class is for views that can contain one or more child views. ViewGroup provides the standardized methods for these classes to use so that they can perform tasks such as adding, removing, getting, and counting child views.

 Iterating through a ViewGroup’s Children
ex:

final int childCount = myViewGroup.getChildCount();
for (int i = 0; i < childCount; i++) {
    View v = myViewGroup.getChildAt(i);
    // Do something with the View
}



FrameLayout
LinearLayout
RelativeLayout
ListView
GridView
Spinner
ViewPager
AdapterViewAnimator
AdapterViewFlipper
AppWidgetHostView
DialerFilter
FragmentBreadCrumbs
GestureOverlayView
GridLayout
HorizontalScrollView
ImageSwitcher
MediaController
PagerTabStrip
PagerTitleStrip
ScrollView
SearchView
SlidingDrawer
StackView
TabHost
TabWidget
TableLayout
TableRow
TextSwitcher
ViewAnimator
ViewFlipper
ViewSwitcher
ZoomControls

圖片縮放

scaleType

resize bitmap:

int width  = 1000;
int height = 500;

Bitmap resizeBitmap = Bitmap.createScaledBitmap(oldBitmap, width, height, true);

JAVA:

 categoryButton.setScaleType(ImageView.ScaleType.FIT_XY );

XML:


  <ImageButton
                android:id="@+id/foodDetailBigBut"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_alignTop="@+id/foodDetailViewPager"
                android:layout_alignLeft="@+id/foodDetailViewPager"
                android:src="@drawable/bigbut"
                android:scaleType="fitXY"
                 android:background="@android:color/transparent"
                />



維持比例縮放:  centerCrop & centerInside
不維持比例，縮放到指定的大小:  fitXY

android UI元件基本介紹

TextView: 顯示文字

EditText: 輸入文字

Button:  按鈕

ImageView: 顯示圖片

ImageButton:  顯示圖片的button

CheckBox,  RadioButton, Switch , ToggleButton

CalendarView

CheckedTextView

DatePicker

RatingBar

SeekBar

Spinner

TimePicker

AnalogClock

Chronometer

DigitalClock

KeyboardView

MediaRouteButton

QuickContactBadge

ProgressBar

WebView

VideoView

split action bar

模擬器的dpi

鍵盤(keyboard)樣式

http://developer.android.com/reference/android/widget/TextView.html#attr_android:inputType

設定inputType

ex:


<EditText android:layout_width="match_parent"
    android:layout_height="40dp"
    android:inputType="textEmailAddress" 
    android:layout_marginTop="10dp"
    android:textColor="#000000"/>

輸入數字和小數點: numberDecimal

只能輸入數字:

 android:inputType="phone"
 android:digits="1234567890"

設定顏色(color)和顏色的透明度

在XML裡設定
ex:
<EditText android:layout_width="match_parent"
    android:layout_height="40dp"
    android:inputType="textEmailAddress"
    android:layout_marginTop="10dp"
    android:textColor="#000000"/>


如果有4個byte，第一個byte設定透明度
ex:
#00000000


從Java設定

ex:

 seperatorView.setBackgroundColor(Color.argb(51, 255, 255, 255));
 wordTextView2.setTextColor(Color.rgb(0,0,0));

ex:
calorieView.getBackground().setAlpha(127);

讓模擬器顯示虛擬鍵盤 (keyboard)

1. 點選Edit button

2. uncheck "Hardware keyboard present"

margin and padding

margin: 外部間距，和其它UI元件的間距

padding: 內部間距，UI元件自己內部的間距

ex:

                android:paddingBottom="20dp"

ex:


layoutParams.setMargins(0, normalCalorieTextViewStartY, 0, 0);

action bar overlay

設定action bar overlay ( themes.xml)


<resources>

    <style name="FitMiTheme" parent="@android:style/Theme.Holo">
          <item name="android:windowActionBarOverlay">true</item>
    </style>


設定UI在action bar之後

從XML

<LinearLayout android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
   android:paddingTop="?android:attr/actionBarSize" >

從Java


                   TypedValue tv = new TypedValue();
   this.getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true);
   int actionBarHeight = getResources().getDimensionPixelSize(tv.resourceId);
   layoutParams.setMargins(0, actionBarHeight, 0, 0);

layout

for layout_height & layout_width:
match_parent & wrap_content

relative layout:

http://developer.android.com/reference/android/widget/RelativeLayout.LayoutParams.html

 it also allows you to create overlapping views and views that appear to float on top of others.

ex:

android:layout_centerHorizontal="true" 

android:layout_toRightOf="@+id/addPeriodStartDateTitleImageView"

linear layout :
延著水平或垂直排列

android:orientation="horizontal"
或
android:orientation="vertical"



ex:


 <LinearLayout android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >

        <Button   android:text="add"
         android:layout_width="0px"
         android:layout_height="wrap_content"
          android:layout_weight="1"
         />
FrameLayout     
         <Button android:text="subtract"
         android:layout_width="0px"
         android:layout_height="wrap_content"
          android:layout_weight="1"
         />
       
      </LinearLayout>
說明:
一樣的weight，兩個button平分畫面 。記得width的寬度要設成0px。


FrameLayout

http://www.onlymobilepro.com/2012/05/22/android-frame-layout-for-absolute-beginner/

一層一層疊view。

java:


layoutParams.addRule(RelativeLayout.BELOW, titleTextView.getId());


RelativeLayout.LayoutParams  layoutParams =  new RelativeLayout.LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);

設定背景圖片或背景顏色

每個UI元件都有background attribute


設定activity的xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/mainbackground"
    tools:context=".MainActivity" >


<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000000"
    tools:context=".MainActivity" >

theme and style

http://mobile.tutsplus.com/tutorials/android/android-sdk-exploring-styles-and-themes/

1. create values/themes.xml
ex:


<?xml version="1.0" encoding="utf-8"?>
<resources>

    <style name="TestTheme" parent="android:Theme.Light">
    </style>

 

</resources>


2. modify AndroidManifest.xml

ex:

<application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/TestTheme" >

App Icon image & Icon title

AndroidManifest.xml


<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.cookbook.simple_activity"
          android:versionCode="1"
          android:versionName="1.0">
    <application android:icon="@drawable/icon"
                  android:label="@string/app_name">
        <activity android:name=".SimpleActivity"
                   android:label="@string/app_name">

app version

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.cookbook.simple_activity"
          android:versionCode="1"
          android:versionName="1.0">

取得硬體資訊

android.os.Build.MODEL

ex:
if(android.os.Build.MODEL.equals("Nexus+One")) { ... }

android documentation

http://developer.android.com/index.html

android version

android version比例圖表 

http://developer.android.com/about/dashboards/index.html 

AndroidManifest.xml:
設定minimum required SDK version and the target SDK version
ex:


<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="17" />

說明:

minSdkVersion:  API >= 8 的皆可安裝

Target SDK version: 一般採用最新的SDK

Build SDK version: 一般採用最新的SDK

設定Build SDK Version

檢查device的version

ex:

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {

        

    }

API version

http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels

設定起始畫面activity( launcher activity )

在AndroidManifest.xml:

ex:


<application
    ... >
    <activity
      android:name="com.bignerdranch.android.geoquiz.QuizActivity"
      android:label="@string/app_name" >
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
    <activity
      android:name=".CheatActivity"
      android:label="@string/app_name" />
  </application>

啟動舊專案

activity的啟動和返回和intent

intent:
Your app should handle reasonable Intents, which is the class Android uses to indicate what the user is trying to do and to find an appropriate app to accomplish that objective
說明:
android會依據intent尋找相關的App來給使用者挑選


利用intent

 public void startActivity(Intent intent);

ex:


Intent i = new Intent(QuizActivity.this, CheatActivity.class);
startActivity(i);


說明:
顯示另一個activity，原本activity的onStop被呼叫.
當按下back鍵後，將回到原來的activity

在activity間傳遞資訊: 透過intent的putExtra & getIntent

ex:


Intent i = new Intent(MainActivity.this, CheatActivity.class);
  boolean answerIsTrue = mAnswerKey[mCurrentIndex].isTrueQuestion();
  i.putExtra(CheatActivity.EXTRA_ANSWER_IS_TRUE, answerIsTrue);
startActivity(i);
說明:傳送



mAnswerIsTrue = getIntent().getBooleanExtra(EXTRA_ANSWER_IS_TRUE, false);

說明: 取得

Getting a result back from a child activity

1.
parent activity呼叫
public void startActivityForResult(Intent intent, int requestCode);
說明 :
之後才能夠取得child activity回傳的資料

2.
child  activity呼叫
 public final void setResult(int resultCode, Intent data);
說明:
回傳結果和Intent，資料包在intent裡。結果有2種:
Activity.RESULT_OK
Activity.RESULT_CANCELED.
這裡的intent有兩種產生方法:
1.  Intent data = new Intent();
2.  Intent i = getIntent();
     get the intent that start this activity


3. parent activity經由onActivityResult取得資料
ex:

  protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (data == null) {
          return;
        }
        mIsCheater = data.getBooleanExtra(CheatActivity.EXTRA_ANSWER_SHOWN, false);
    }
說明:
利用requestCode判斷是從哪個activity回來




返回:
按下back鍵或是activity物件呼叫finish method


Explicit intents:
explicitly defines the component which should be called by the Android system, by using the Java class as identifier.
ex:
Intent i = new Intent(this, ActivityTwo.class);


Implicit Intents:
Implicit intents specify the action which should be performed and optionally data which provides data for the action.

ex:

Intent i = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.vogella.com"));
startActivity(i);

說明:
The most commonly used intent filter is an action,