[Android]初學 使用Intent在Activity傳值(二)

Bundle的傳值，只是單純的A-->B , B-->C 單向傳值 

不像上一篇講到的AB互傳溝通

因此Bundle傳值時，給出的畫面是一個新的、乾淨的初始畫面

範例:

	public class MainActivity extends AppCompatActivity {
	private Button widget2;
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_main);
	widget2 =(Button)findViewById(R.id.btnNext2);
	//接收SecondActivity bundle傳來的參數
	Bundle param = getIntent().getExtras();
	if(param !=null)
	{
	setTitle(param.getString("bparam"));
	}
	//利用bundle傳參數到ScondActivity
	widget2.setOnClickListener(new Button.OnClickListener() {
	public void onClick(View v) {
	Intent intent2 = new Intent();
	Bundle bundle= new Bundle();
	bundle.putString("sourse","bundle from Main");
	intent2.setClass(MainActivity.this, widgetActivity2.class);
	intent2.putExtras(bundle);
	startActivity(intent2);
	}
	});
	}
	}

view raw Main.java hosted with ❤ by GitHub

	public class SecondActivity extends AppCompatActivity {
	private Button prev;
	@Override
	public void onCreate(Bundle savedInstanceState){
	super.onCreate(savedInstanceState);
	setContentView(R.layout.widget2);
	//接收Main 傳來的參數
	Bundle bundle = getIntent().getExtras();
	if(bundle !=null)
	{
	setTitle(bundle.getString("sourse"));
	}
	prev =(Button)findViewById(R.id.button1);
	//Bundle傳送參數到Main
	prev.setOnClickListener(new Button.OnClickListener() {
	public void onClick(View v) {
	Intent intent = new Intent();
	intent.setClass(widgetActivity2.this, MainActivity.class);
	// Bundle 傳送參數
	Bundle param = new Bundle();
	param.putString("bparam", "from widget2");
	intent.putExtras(param);
	startActivity(intent);
	}
	});

view raw Second.java hosted with ❤ by GitHub

[Android]初學 使用Inten在Activity傳值(一)

Main畫面:

點下widget1按鈕，會將 "from Main" 帶到 Second畫面

Second畫面 :

點上一頁按鈕，會回傳 "from widget1"到Main
如果不是點上一頁按鈕兒是透過其他方法回到前一頁，在Main會顯示 "無參數"

startActivityForResult()除了傳值之外，還會回傳一個requestCode
所以Main要加入onActivityResult()方法,來接收辨別是哪個Activity回傳的requestCode


參數一定是從A-->B , B-->A AB兩個Activity在溝通
傳回參數的時候，只會接收參數，畫面不會刷新成預設畫面


最後要記得在AndroidManifest.xml 註冊 Activity

<activity android:name=".SecondActivityName"></activity>

	public class MainActivity extends AppCompatActivity {
	private Button widget1;
	private int REQUEST_CODE;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_main);
	widget1 =(Button)findViewById(R.id.btnNext);
	//下一頁
	widget1.setOnClickListener(new Button.OnClickListener() {
	public void onClick(View v) {
	Intent intent1 = new Intent();
	intent1.setClass(MainActivity.this, widgetActivity.class);
	intent1.putExtra("activityMain", "from Main");
	//當 REQUEST_CODE =-1 等於執行 startActivity
	// widgetActivity 回傳資料要使用 setResult
	startActivityForResult(intent1,REQUEST_CODE);
	//startActivity(intent1);
	//MainActivity.this.finish();
	}
	});
	}
	//接收回傳值的 Function
	@Override
	protected void onActivityResult(int requestCode , int resultCode,Intent data)
	{
	if(requestCode == REQUEST_CODE)
	{
	if (resultCode == RESULT_OK){
	String temp=null;
	Bundle extras = data.getExtras();
	if(extras != null)
	{
	temp = extras.getString("widget");
	}
	setTitle(temp);
	}else
	{
	setTitle("無參數");
	}
	}
	}
	}

view raw MainActivity.java hosted with ❤ by GitHub

	public class widgetActivity extends AppCompatActivity {
	private Button prev;
	private String data;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.widget);
	prev=(Button)findViewById(R.id.btnPrev);
	Bundle extras =getIntent().getExtras();
	if(extras !=null)
	{
	data=extras.getString("activityMain");
	setTitle("widget :" + data);
	}else
	{
	setTitle("widget");
	}
	prev.setOnClickListener(new Button.OnClickListener(){
	public void onClick(View v)
	{
	Intent intent =new Intent();
	intent.setClass(widgetActivity.this,MainActivity.class);
	// Bundle 傳遞 Data
	Bundle bundle = new Bundle();
	bundle.putString("widget","from widget1");
	intent.putExtras(bundle);
	setResult(RESULT_OK, intent);
	finish();
	}
	});
	}

view raw widgetActivity.java hosted with ❤ by GitHub

[Android]初學-控制項應用

1. 按下按鈕，顯示EditView輸入的內容和選到的CheckBox
2. 顯示框出現,利用RadioGroup選擇Show出訊息或隱藏訊息
3. 按下清除按鈕，EditView、CheckBox 回復初始狀態

	public class MainActivity extends AppCompatActivity {
	private Button press;
	private Button clear;
	private TextView Name;
	private TextView msg;
	private ArrayList<CheckBox> cbList = new ArrayList<CheckBox>();
	private RadioGroup rGroup;
	private RadioButton btnShow;
	private RadioButton btnHide;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_main);
	findView();
	SetDefault();
	//msg內容
	press.setOnClickListener(new Button.OnClickListener(){
	@Override
	public void onClick(View v){
	String r="";
	//第一種CheckBox批次跑迴圈寫法
	int ckID[]={R.id.checkBox1,R.id.checkBox2,R.id.checkBox3,R.id.checkBox4,R.id.checkBox5,R.id.checkBox6};
	CheckBox a =null;
	for(int i=0 ;i<ckID.length;i++)
	{
	if((a=(CheckBox)findViewById(ckID[i]))!=null)
	{
	if(a.isChecked())
	{
	r+=a.getText()+",";
	}
	}
	}
	setTitle("MyApp1 Name:" + Name.getText());
	msg.setText("checked: " + r.substring(0,r.length()-1) );
	rGroup.setVisibility(View.VISIBLE);
	}
	});
	//控制 msg可見
	rGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
	@Override
	public void onCheckedChanged(RadioGroup group, int checkedId) {
	if (checkedId == btnHide.getId()) {
	msg.setVisibility(View.GONE);
	} else if (checkedId == btnShow.getId()) {
	msg.setVisibility(View.VISIBLE);
	}
	}
	});
	}
	private void findView(){
	msg=(TextView)findViewById(R.id.textView4);
	press = (Button)findViewById(R.id.button1);
	clear=(Button)findViewById(R.id.btnclear);
	Name=(TextView)findViewById(R.id.editText);
	rGroup=(RadioGroup)findViewById(R.id.rGroup);
	btnShow =(RadioButton)findViewById(R.id.radioButton1);
	btnHide =(RadioButton)findViewById(R.id.radioButton2);
	CheckBox ck1 =(CheckBox)findViewById(R.id.checkBox1);
	CheckBox ck2 =(CheckBox)findViewById(R.id.checkBox2);
	CheckBox ck3 =(CheckBox)findViewById(R.id.checkBox3);
	CheckBox ck4 =(CheckBox)findViewById(R.id.checkBox4);
	CheckBox ck5 =(CheckBox)findViewById(R.id.checkBox5);
	CheckBox ck6 =(CheckBox)findViewById(R.id.checkBox6);
	cbList.add(ck1);
	cbList.add(ck2);
	cbList.add(ck3);
	cbList.add(ck4);
	cbList.add(ck5);
	cbList.add(ck6);
	}
	//清除
	private void SetDefault(){
	clear.setOnClickListener(new Button.OnClickListener(){
	@Override
	public void onClick(View v)
	{
	//第二種CheckBox批次跑迴圈寫法
	//批次取消CheckBox選項
	for (CheckBox c: cbList) {
	c.setChecked(false);
	}
	msg.setText("Click Clear");
	Name.setText("");
	setTitle("MyApp1");
	msg.setVisibility(View.VISIBLE);
	rGroup.setVisibility(View.GONE);
	}
	});
	}
	//msg可見
	private void SetMsgVisiable(){
	}
	public boolean onCreateOptionsMenu(Menu menu) {
	// Inflate the menu; this adds items to the action bar if it is present.
	getMenuInflater().inflate(R.menu.menu_main, menu);
	return true;
	}
	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
	// Handle action bar item clicks here. The action bar will
	// automatically handle clicks on the Home/Up button, so long
	// as you specify a parent activity in AndroidManifest.xml.
	int id = item.getItemId();
	//noinspection SimplifiableIfStatement
	if (id == R.id.action_settings) {
	return true;
	}
	return super.onOptionsItemSelected(item);
	}
	}

view raw .java hosted with ❤ by GitHub

	<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:paddingBottom="@dimen/activity_vertical_margin"
	android:paddingLeft="@dimen/activity_horizontal_margin"
	android:paddingRight="@dimen/activity_horizontal_margin"
	android:paddingTop="@dimen/activity_vertical_margin"
	tools:context=".MainActivity">
	<TextView
	android:id="@+id/txt1"
	android:layout_width="fill_parent"
	android:layout_height="wrap_content"
	android:autoText="false"
	android:text="@string/hello_world"
	/>
	<EditText
	android:id="@+id/editText"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:ems="10"
	android:inputType="textPersonName"
	android:layout_marginTop="29dp"
	android:hint="請輸入姓名"
	android:layout_below="@+id/txt1"
	android:layout_centerHorizontal="true" />
	<TextView
	android:id="@+id/textView"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:text="帳號"
	android:textAppearance="?android:attr/textAppearanceLarge"
	android:layout_alignBaseline="@+id/editText"
	android:layout_alignBottom="@+id/editText"
	android:layout_alignParentStart="true" />
	<CheckBox
	android:id="@+id/checkBox1"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:checked="false"
	android:text="寫程式"
	android:textSize="@dimen/abc_text_size_small_material"
	android:layout_below="@+id/editText"
	android:layout_alignParentStart="true"
	android:layout_marginTop="27dp" />
	<CheckBox
	android:id="@+id/checkBox2"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:layout_alignTop="@+id/checkBox1"
	android:layout_marginStart="23dp"
	android:layout_toEndOf="@+id/checkBox1"
	android:checked="false"
	android:text="聽音樂" />
	<CheckBox
	android:id="@+id/checkBox3"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:layout_alignBottom="@+id/checkBox2"
	android:layout_marginStart="30dp"
	android:layout_toEndOf="@+id/checkBox2"
	android:checked="false"
	android:text="看書" />
	<Button
	android:id="@+id/button1"
	android:layout_width="match_parent"
	android:layout_height="wrap_content"
	android:text="顯示"
	android:layout_centerVertical="true"
	android:layout_alignParentStart="true" />
	<Button
	android:layout_width="match_parent"
	android:layout_height="wrap_content"
	android:text="清除"
	android:id="@+id/btnclear"
	android:layout_below="@+id/button1"
	android:layout_alignParentStart="true" />
	<TextView
	android:id="@+id/textView4"
	android:layout_width="fill_parent"
	android:layout_height="wrap_content"
	android:textColor="#405dff"
	android:layout_below="@+id/rGroup"
	android:layout_alignParentStart="true"
	android:layout_alignParentBottom="true" />
	<RadioGroup
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:layout_below="@+id/btnclear"
	android:layout_alignParentStart="true"
	android:id="@+id/rGroup"
	android:visibility="invisible">
	<RadioButton
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:text="show msg"
	android:id="@+id/radioButton1"
	android:checked="true"
	/>
	<RadioButton
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:text="Hide msg"
	android:id="@+id/radioButton2"
	android:layout_below="@+id/btnclear"
	android:layout_alignParentStart="true"
	android:checked="false"
	/>
	</RadioGroup>
	<CheckBox
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:text="運動 "
	android:id="@+id/checkBox4"
	android:layout_below="@+id/checkBox1"
	android:layout_alignParentStart="true"
	android:checked="false" />
	<CheckBox
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:text="睡覺"
	android:id="@+id/checkBox5"
	android:checked="false"
	android:layout_below="@+id/checkBox2"
	android:layout_alignStart="@+id/checkBox2" />
	<CheckBox
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:text="看電影"
	android:id="@+id/checkBox6"
	android:checked="false"
	android:layout_below="@+id/checkBox3"
	android:layout_toEndOf="@+id/checkBox5"
	android:layout_alignStart="@+id/checkBox3" />
	</RelativeLayout>

view raw .xml hosted with ❤ by GitHub

[Android] 基本Layout屬性

版面方向

android:orientation vertical :縱向 版面由上到下horizontal:橫向

寬高設定

android:layout_width
android:layout_height

fill_parent:寬或高滿版
wrap_content:寬或高自動調整,顯示完整內容
match_parent:同fill_parent

設定View的相對位置

android:layout_gravity

設定View內容的位置

android:gravity