memory

activity_main.xml

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<EditText
android:id="@+id/editText1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:textSize="26sp"
android:hint="x value"
android:inputType="numberSigned"/>
<EditText
android:id="@+id/editText2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:textSize="26sp"
android:hint="y value"
android:inputType="numberSigned"/>
<Button
android:id="@+id/btn1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="toast meesage"
android:textSize="20sp"
android:onClick="onBtnClicked"/>
</LinearLayout>
<Button
android:id="@+id/btn2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text = "toast shape change"
android:onClick="onBtn2Clicked"
android:layout_gravity="center"
android:textSize="20sp"/>

toast_boarder.xml

<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="30sp"
android:padding="10dp"
android:background="@drawable/toast_background"/>

toast_background.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<stroke
android:width="5dp"
android:color="#00f"/>
<solid
android:color="#0ff"/>
<padding
android:left="20dp"
android:top="20dp"
android:right="20dp"
android:bottom="20dp"/>
<corners
android:radius="20dp"/>
</shape>

MainActivity.java

public class MainActivity extends AppCompatActivity {
EditText editText1;
EditText editText2;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

editText1 = findViewById(R.id.editText1);
editText2 = findViewById(R.id.editText2);
}
public void onBtnClicked(View v){
try {
Toast toast = Toast.makeText(context: this, text: "hahaha", Toast.LENGTH_LONG);
int xValue = Integer.parseInt(editText1.getText().toString());
int yValue = Integer.parseInt(editText2.getText().toString());
//입력된 좌표값을 가져온다
toast.setGravity(gravity: Gravity.TOP| Gravity.TOP, xValue, yValue);
toast.show();
}catch(NumberFormatException e){
e.printStackTrace();
}
}
//toast message 모양 바꾸기
public void onBtn2Clicked(View v){
LayoutInflater inflater = getLayoutInflater();

View layout = inflater.inflate(R.layout.toast_boarder, (ViewGroup)findViewById(R.id.toast_layout));

TextView textView = layout.findViewById(R.id.textView);

Toast toast = new Toast(context: this);
textView.setText("style changed toast");
toast.setGravity(Gravity.CENTER, xOffset: 0, yOffset: -50);
toast.setDuration(Toast.LENGTH_SHORT);
toast.setView(layout);

toast.show();
}
}

layout은 화면구성을 정의해놓은 파일로

화면에 보여지도록 하기위해 java code가 필요하다

*.xml에서 정의한 layout을 Inflater를 통해 객체화를하고

객체화를 한후 *.java를 통해 화면에 보이도록 한다.

setContentView(R.layout.*) method를통해

화면에 보여줄 view를 지정(매개변수) 하고

객체화(memory loading)을 한다

R은 app/res를 의미한다

setContentView 는 전체화면만 객체화를하고

LayInflater를 통해 부분작업 객체화를 한다

activity_main.xml

<TextView
android:id="@+id/txtView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="inflation test"
android:layout_marginTop = "30dp"
android:textSize = "30sp"
android:textColor = "#a63"
android:layout_gravity = "center"/>
<Button
android:id="@+id/btn1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text = "add layout"
android:textSize = "30sp"
android:onClick="onClickedBtn"/>
<LinearLayout
android:id="@+id/addLayout"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
</LinearLayout>

add_layout.xml

<Button
android:id="@+id/btnTest"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text = "test"
android:textSize = "20sp"
android:textStyle = "bold"/>
<RadioGroup
android:id="@+id/radioGroup"
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp">
<RadioButton
android:id="@+id/radioBtn1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="sport"
android:textColor="#00f"
android:textStyle="bold"
android:textSize="20dp"
android:layout_marginRight="5dp"/>
<RadioButton
android:id="@+id/radioBtn2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="travel"
android:textColor="#00f"
android:textStyle="bold"
android:textSize="20dp"
android:layout_marginRight="5dp"/>
<RadioButton
android:id="@+id/radioBtn3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="reading"
android:textColor="#00f"
android:textStyle="bold"
android:textSize="20dp"
android:layout_marginRight="5dp"/>
<RadioButton
android:id="@+id/radioBtn4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="gaming"
android:textColor="#00f"
android:textStyle="bold"
android:textSize="20dp"
android:layout_marginRight="5dp"/>
</RadioGroup>
<LinearLayout
android:gravity="center"
android:layout_width="match_parent"
android:layout_height="wrap_content">
android:layout_margin="10dp"
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="accept"
android:textSize="20sp"
android:layout_margin="10dp"
android:textColor="#f00"/>
<CheckBox
android:id="@+id/agree"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//전체화면에 대한 뷰를 지정하고, inflation을 한다
}
//when button is clicked, add layout
public void onClickedBtn(View v){
addLayout();
}
//add_layout.sml을 activity_main.xml에 추가하는 기능의 method
private void addLayout(){
LinearLayout parentLayout = findViewById(R.id.addLayout);

//inflation
LayoutInflater inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(R.layout.add_layout, parentLayout, true);

Button btnTest = findViewById(R.id.btnTest);
final CheckBox agree = findViewById(R.id.agree);

btnTest.setOnClickListener(new View.OnClickListener(){
public void onClick(View v){
if(agree.isChecked()){
agree.setChecked(false);
}else{
agree.setChecked(true);
}
}
});
}
}

activity_main.xml

<GridView
android:id="@+id/gridView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:numColumns="3"
android:padding="10dp"
android:horizontalSpacing="10dp"
android:verticalSpacing="20dp"
android:gravity="center">
</GridView>

CustomAdapter.java

public class CustomAdapter extends BaseAdapter {
//BaseAdapter를 상속받는다
private Context mContext;
private int[] data;

public CustomAdapter(Context mContext, int[] data){
this.mContext = mContext;
this.data = data;
}

public int getCount(){
return data.length;
}//getCount method를 통해 data의 갯수를 얻어온다
public Object getItem(int position){
return data[position];
}
public long getItemId(int position){
return position;
}

public View getView(int position, View convertView, ViewGroup parent){
ImageView imageView;

if(convertView == null){
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(w: 150, h: 150));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(left: 5, top: 5, right: 5, bottom: 5);
}else{
imageView = (ImageView)convertView;
}
imageView.setImageResource(data[position]);
return imageView;
}
}

MainActivity.java

public class MainActivity extends AppCompatActivity {

private int[] imgData = {R.drawable.apple, R.drawable.apple,
R.drawable.apple, R.drawable.apple, R.drawable.apple, R.drawable.apple,
R.drawable.apple, R.drawable.apple, R.drawable.apple, R.drawable.apple,
R.drawable.apple, R.drawable.apple, R.drawable.apple, R.drawable.apple};
private CustomAdapter adapter;
private GridView gridView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

adapter = new CustomAdapter(mContext: this, imgData);

gridView = findViewById(R.id.gridView);
gridView.setAdapter(adapter);
}
}

--------------------

activity_main.xml

<GridView
android:id="@+id/gridView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:numColumns="3"
android:padding="10dp"
android:horizontalSpacing="10dp"
android:verticalSpacing="20dp"
android:gravity="center">
</GridView>

Grid_item.java

public class Grid_item {
String apple;
int resId;

public Grid_item(String apple, int resId){
this.apple = apple;
this.resId = resId;
}

public String getApple(){
return apple;
}
public void setApple(String apple){
this.apple = apple;
}
public int getResId(){
return resId;
}
public void setResId(int resId){
this.resId = resId;
}
}

item_style.xml

<ImageView
android:id="@+id/imgView"
android:layout_width="100dp"
android:layout_height="100dp"
android:src="@drawable/apple"/>
<TextView
android:id="@+id/txtView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="apple"
android:textColor="#5505ff"
android:textStyle="bold"
android:layout_gravity="center"/>

GridItemView.java

public class GridItemView extends LinearLayout {
ImageView imageView;
TextView textView;

public GridItemView(Context context){
super(context);
init(context);
}
public void init(Context context){
LayoutInflater inflater = (LayoutInflater)context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(R.layout.item_style, this, true);

imageView = findViewById(R.id.imgView);
textView = findViewById(R.id.txtView);
}
public void setImage(int resId){
imageView.setImageResource(resId);
}
public void setApple(String apple){
textView.setText(apple);
}
}

CustomAdapter.java

public class CustomAdapter extends BaseAdapter {
//BaseAdapter를 상속받는다
private Context mContext;
ArrayList<Grid_item> data = new ArrayList<Grid_item>();

public CustomAdapter(Context mContext){
this.mContext = mContext;
}

public void addItem(Grid_item grid_item){
data.add(grid_item);
}

public int getCount(){
return data.size();
}//getCount method를 통해 data의 갯수를 얻어온다
public Object getItem(int position){
return data.get(position);
}
public long getItemId(int position){
return position;
}

public View getView(int position, View convertView, ViewGroup parent){

GridItemView view = new GridItemView(mContext);
Grid_item item = data.get(position);

view.setImage(item.getResId());
view.setApple(item.getApple());

return view;
}
}

MainActivity.java

public class MainActivity extends AppCompatActivity {

private CustomAdapter adapter;
private GridView gridView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

gridView = findViewById(R.id.gridView);

adapter = new CustomAdapter(this);
adapter.addItem(new Grid_item("apple", R.drawable.apple));
adapter.addItem(new Grid_item("apple", R.drawable.apple));
adapter.addItem(new Grid_item("apple", R.drawable.apple));
adapter.addItem(new Grid_item("apple", R.drawable.apple));
adapter.addItem(new Grid_item("apple", R.drawable.apple));
adapter.addItem(new Grid_item("apple", R.drawable.apple));
adapter.addItem(new Grid_item("apple", R.drawable.apple));
adapter.addItem(new Grid_item("apple", R.drawable.apple));
adapter.addItem(new Grid_item("apple", R.drawable.apple));

gridView.setAdapter(adapter);
}
}

activity_main.xml

<TextView
android:id="@+id/txt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#80f0"
android:gravity="center"
android:text="country"
android:textSize="30dp" />
<Spinner
android:id="@+id/sp01"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="10dp" />

MainActivity.java

public class MainActivity extends AppCompatActivity {
TextView textView;
Spinner spinner;
ArrayAdapter<String> adapter = null;

String[] items = {"korea", "china", "japan", "france"};

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

textView = findViewById(R.id.txt);
spinner = findViewById(R.id.sp01);
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, items);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

spinner.setAdapter(adapter);
}
}

---seperate data---

activity_main.xml

<TextView
android:id="@+id/txt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#80f0"
android:gravity="center"
android:text="country"
android:textSize="30dp" />
<Spinner
android:id="@+id/sp01"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="10dp" />

country.xml

<string-array name="country">
<item>korea</item>
<item>china</item>
<item>japan</item>
<item>france</item>
</string-array>

MainActivity.java

public class MainActivity extends AppCompatActivity {

Spinner spinner;
ArrayAdapter<CharSequence> adapter = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

spinner = findViewById(R.id.sp01);
adapter = ArrayAdapter.createFromResource(this, R.array.country, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

spinner.setAdapter(adapter);
}
}

Adapter가 data를 가져와서 getview() method를 통해 Adapter View형태로 보여준다

Adapter의 종류에는 ArrayAdapter, SimpleAdapter, cursorAdapter가 있다

Adapter View의 종류에는 ListView, GridView, Spinner, Gallery등이 있다

activity_main.xml

<ListView
android:id="@+id/listView"
android:layout_width="match_parent"
android:layout_height="match_parent">
</ListView>

MainActivity.java

public class MainActivity extends AppCompatActivity {

ArrayList<String> arrayList = null;
ArrayAdapter<String> adapter = null;
ListView listView = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

arrayList = new ArrayList<String>();
arrayList.add("jusung");
arrayList.add("aaaaa");
arrayList.add("bbbbb");
arrayList.add("ccccc");
arrayList.add("ddddd");
arrayList.add("eeeee");
arrayList.add("fffff");
arrayList.add("ggggg");
arrayList.add("hhhhh");
arrayList.add("iiiii");
arrayList.add("jjjjjj");

adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, arrayList);

listView = findViewById(R.id.listView);
listView.setAdapter(adapter);
//adapter를 통해 화면에 보여준다
}

}

---seperate data---

activity_main.xml

<ListView
android:id="@+id/listView"
android:layout_width="match_parent"
android:layout_height="match_parent">
</ListView>

MainActivity.java

public class MainActivity extends AppCompatActivity {

ArrayAdapter<CharSequence> arrayAdapter = null;
ListView listView = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

//createFromResource() method를 이용해 resource로부터 adapter를 생성
arrayAdapter = ArrayAdapter.createFromResource(this, R.array.contact, android.R.layout.simple_list_item_checked);
//ctr+space bar를 눌러서 다른 목록을 선택할수있다.
listView = findViewById(R.id.listView); //listView를 가져온다
listView.setAdapter(arrayAdapter);

listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
//listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
//multiple일때 여러개 선택가능하다

//ColorDrawable객체를 이용해 구분선에 색을추가할수있다
ColorDrawable colorDrawable = new ColorDrawable(Color.BLUE);
listView.setDivider(colorDrawable);
listView.setDividerHeight(5);
}

}

data.xml

//res\values\data.xml

<resources>
<string-array name="contact">
<item>fffff 010010010</item>
<item>eeeee 010010010</item>
<item>ddddd 010010010</item>
<item>ccccc 010010010</item>
<item>bbbbb 010010010</item>
<item>aaaaa 010010010</item>
</string-array>
</resources>

---listActivity---

MainActivity.java

public class MainActivity extends ListActivity {
//ListActivity를 상속받는다
ArrayList<String> data = null;
ArrayAdapter<String> adapter = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.activity_main);
//ListActivity에 listView가 포함되있다

data = new ArrayList<String>();
data.add("aaaaa");
data.add("bbbbb");
data.add("ccccc");
data.add("ddddd");
data.add("eeeee");
data.add("fffff");
data.add("ggggg");
data.add("hhhhh");
data.add("iiiii");

adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, data);

setListAdapter(adapter);
//ListActivity에 setListAdapter method를 이용해 adapter를 추가시킨다
}
}

---listActivity---

MainActivity.java

public class MainActivity extends ListActivity {
//ListActivity를 상속받는다
String[] laughing = {"haha","hoho","hihi","hehe","huhu","hwhw"};
ArrayAdapter<String> adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.activity_main);
//ListActivity에 listView가 포함되있다

adapter = new ArrayAdapter<String>(this, R.layout.activity_list_style,
R.id.laugh, laughing);
//직접만든 activity_list_style로 지정한다
//actvity_list_style에 만든 text view의 id값에 data laughing를 입력한다

setListAdapter(adapter);
//ListActivity에 setListAdapter method를 이용해 adapter를 추가시킨다
}
}

activity_list_style.xml

//res\layout에 activity_list_style.xml를 만든다

<ImageView
android:id="@+id/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_launcher_foreground"/>
<TextView
android:id="@+id/laugh"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="24sp"
android:paddingTop="50dp"/>

MainActivity.java

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.activity_main);
// 주석처리해준다

Custom custom = new Custom(this);
setContentView(custom);
//custom 객체 생성후 불러온다
}

Custom.java

public class Custom extends View {
//View를 상속받는다
private Paint paint;

public Custom(Context context){
super(context);
}//view class에 context호출하는 생성자생성

protected void onDraw(Canvas canvas){
canvas.drawColor(Color.CYAN);
//CYAN color의 도화지생성

paint = new Paint();
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(3.0F);
//STROKE는 테두리를 나타내고 default값은 FILL이다
paint.setColor(Color.GREEN);
canvas.drawCircle(500, 500, 300, paint);
//x,y 좌표 500에 300 반지름의 green 원이 생긴다

paint = new Paint();
paint.setStyle(Paint.Style.FILL);
paint.setColor(Color.MAGENTA);
canvas.drawCircle(500, 500, 300, paint);
//위에 원과 겹쳐 원에 테두리가 있는것처럼보인다

paint.setStyle(Paint.Style.FILL);
paint.setColor(Color.BLUE);
paint.setARGB(255,255,0,0);
//a는 0~255사이의값으로 투명도를 나타낸다
canvas.drawRect(10,10,200,200,paint);
//왼쪽 상단과 오른쪽 상단의 좌표를 지정한다

paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(10.0F);
//STROKE로 설정할경우 테두리가그려진다
paint.setColor(Color.BLUE);
paint.setARGB(255,0,255,0);
canvas.drawRect(10,210,200,400,paint);

DashPathEffect dashPathEffect = new DashPathEffect(new float[]{5,5}, 1);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(10.0F);
paint.setPathEffect(dashPathEffect);
//점선을 만든다
paint.setColor(Color.BLUE);
canvas.drawRect(220,210,400,410,paint);

//TEXT
paint.setStyle(Paint.Style.FILL);
paint.setTextSize(100);
canvas.drawText("it is jusung", 300, 900,paint);
}
}

----Button, RadioButton, CheckBox----

activity_main.xml

<TextView
android:id="@+id/txt01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="pay now"
android:textSize="25sp"
android:layout_margin="10dp"/>
<RadioGroup
android:id="@+id/rGroup01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:padding="10dp"
android:orientation="horizontal">
<RadioButton
android:id="@+id/rBtn01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:text="Card"
android:textSize="25sp"
android:textColor="#33aa88"
android:textStyle="bold"/>
<RadioButton
android:id="@+id/rBtn02"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:text="phone"
android:textSize="25sp"
android:textStyle="bold"
android:textColor="#33aa88"/>
<RadioButton
android:id="@+id/rBtn03"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:text="bank"
android:textSize="25sp"
android:textStyle="bold"
android:textColor="#33aa88"/>
</RadioGroup>
<!--버튼이 하나씩만 작동할수 있게 하려면 RadioGroup으로 묶어줘야한다-->
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_marginBottom="30dp"
android:gravity="right">
<CheckBox
android:id="@+id/chkBox01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="accept terms"
android:textSize="20sp"
android:layout_marginRight="45dp"/>
</LinearLayout>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="pay now"
android:textSize="25sp"
android:textStyle="bold"
android:layout_gravity="center_horizontal"/>

----imageView----

image file을 res\drawable에 저장후

@drawable/file_name(only lowercase)을 이용해 불러올수있다

activity_main.xml

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/hey"
android:maxWidth="300dp"
android:adjustViewBounds="true"/>
<!--크기 조절을위해선 layout크기를 wrap_content로 해야하고
adjustViewBoudns에 true값을 줘야한다-->
<!--maxHeight 값을 입력안할시 가로비율에맞춰 크기가조정된다=-->
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="@drawable/hey"
android:scaleType="matrix"/>
<!--scaleType을 설정하지 않을경우 사진이 중앙으로
가로, 세로비율이 자동으로 조절되서 오게된다
scaleType="fitXY"로 설정할경우 화면 크기로 image size가 조절된다
fitXY로 설정후 Width와 Height값을통해 사진크기를 조절할수있다-->

----image button---

activity_main.xml

<ImageButton
android:id="@+id/imgBtn"
android:layout_width="100dp"
android:layout_height="100dp"
android:background="@drawable/button"
android:contentDescription="turn off"
android:layout_gravity="center"/>
<!--src로 img를 불러올경우 border이 생겨서 background로 불러온다-->
<!--contentDescription을통해 button설명글을 추가할수있다-->

----text view----

1. activity_main.xml

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/app_name"
android:textSize="30sp" />
<!--app, res, values, strings.xml에서 text를 따로 관리할수있다
string tag와 name을 이용해 불러올수있다-->
<!--text color는 #AARRGGBB 로 정의할수있다
AA는 투병도로 00은 완전투명 77는 반투명 FF는 완전불투명-->
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/test"
android:textSize="30sp" />
<!--다국어로 이용할경우 resource안에
values-en/strings.xml, values-ko/string.xml 와같이 만든후
단말기 setting으로 각 언어를 불러올수있다-->
<TextView
android:id="@+id/txtView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/marquee"
android:textSize="30sp"
android:singleLine="true"
android:focusable="true"
android:ellipsize="marquee"/>

<!--android:singleLine="true"를 할경우 뒷부분이 ...으로 한줄에 표시된다 -->
<!--android:ellipsize="start, middle, end, marquee"로 뒷부분 ...을 조정가능-->

<!--marquee 속성을 이용하려면 singleline, focusable 값에 true를 설정하고
java코드를 작성해준다. marqueeRepeatLimit="forever"를통해 반복횟수를 조절할수있다-->

<!--android:maxLines="1"을 이용해 표시될 줄을 설정할수있다-->
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="sndroid"
android:textSize="70sp"
android:textStyle="bold|italic"/>
<!--android:typeface="serif, sans, monospace"와 같이 지정할수있고
android:fontFamily="sans-serif"와 같이 글꼴을 지정할수도있다-->
<!--android:textStyle="Normal, Bold, Italic" 과같이 변경할수있다
두가지의 style을 적용할경우 | 를 이용한다-->
</LinearLayout>

2. strings.xml

<resources>
<string name="app_name">My Application</string>
<string name="test">test</string>
<string name="marquee">testtesttestsetsetsetstsetsetsetestsetsetestest</string>
</resources>

<!--name을 설정후 TextView를 이용해 사용할수있다-->

3. MainActivity.java

TextView textView;

textView = findViewById(R.id.txtView);
textView.setSelected(true);

<!--marquee 옵션이 작동할수있게 한다-->

----edit text-----

activity_main.xml

<EditText
android:id="@+id/nameInput"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="20sp"
android:inputType="text"
android:hint="put your name"/>
<!--input Type 설정시 키보드가 알맞게 변경된다-->

<!--inputType="number" or "textEmailAddress 가올수있다-->