Intent to Activity or Context 意圖分享純文本，
使用 IntentBuilder 取代 Intent
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design layout with UI element. And add on Guideline to make a space between ImageView & ImageButton.
//activity_main.xml <?xml encoding="utf-8"?> <layout> <data> <variable name="price" type="Integer" /> <variable name="volume" type="Integer" /> </data> <androidx.constraintlayout.widget.ConstraintLayout tools:context=".MainActivity" > <ImageView android:id="img" android:scaleType="centerCrop" android:srcCompat="@drawable/aaa" /> <androidx.constraintlayout.widget.Guideline android:id="@+id/ggg" android:orientation="" app:layout_constaintGuide_end="@dimen/default_spacing" /> <TextView android:id="@+id/price" /> <TextView android:id="@+id/volume" /> <ImageButton android:id="imgB" android:scaleType="centerCrop" tools:src="https://github.com/QueenieCplusplus/@drawable/bbb" /> </androidx.constraintlayout.widget.ConstraintLayout> </layout> -
define dimens.
// go to app/src/main/res/values/dimens.xml <?xml encoding="utf-8"?> <resources> <dimen name="default_spacing"> 16dp </dimen> </resources> -
define customed color.
// go to app/src/main/res/values/colors.xml <?xml encoding="utf-8"?> <resources> <color name="white">#ffffff</color> <color name="green">#6ab343</color> <color name="grey">#99000000</color> </resources> -
define resorces in app/src/main/res/drawable.
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design menu resource.
// go to app/src/main/res/menu // main_menu.xml <?xml encoding="utf-8"> <menu> <item android:id="@+id/showMenuTouch" android:icon="?android:attr/actionModeShareDrawable" android:visible="true" andrdoid:enable="true" android:showAsAction="ifRoom" /> </menu> -
to create a R.string which is located in file called string.xml under dir res/values/.
<resources> <string name="app_name">Kates App</string> <string name="dollar_sign">$</string> <string name="zero">0</string> <string name="garmin">Garmin Watch</string> <string name="share_text">I\'ve clicked %1$d Desserts for a total of %2$d$ #AndroidDessertClicker</string> <string name="share">Share</string> <string name="sharing_not_available">Sharing Not Available</string> </resources> -
source line of code.
package com.example.android.katesapp [default module] import android.os.bundle import androidx.appcompat.app.AppCompatActivity [databind module] import androidx.databinding.DataBindingUtil import com.example.android.katesapp.databinding.ActivityMainBinding [intent module] import androidx.core.app.ShareCompat [system error handler module] import android.content.ActivityNotFoundException [menu module] import android.view.Menu import android.view.MenuItem [Toast module] import android.widget.Toast class MainActivity: AppCompatActivity(){ // 類別中的共用變數 private var price = 0 private var volume = 0 private lateinit var binding: ActivityMainBinding // 製作資料型別 // data class garminWatchToBuy(val) // create a Data Type // Data Class // it includes the resource id. data class garmin3C(val imgId: Int, val price: Int, val volumn: Int) // 建立集合裝載資料型別的成員 // create a List // 拆解集合為成員 private val allGarmin3C = listOf( garmin3C(R.drawable.watchA, 6990, 5), garmin3C(R.drawable.watchB, 7990, 15), garmin3C(R.drawable.watchC, 19900, 20) ) // 提取集合中的成員，成員有 id、價格、數量等屬性 private var currentWatch = allGarmin[0] override fun onCreate(savedInstanceState: Bundle?){ super.onCreate(savedInstanceState) // 綁定 UI 元件 binding = DataBindingUtil.setContentView(this, R.layout.activity_main) // 顯示 UI 元件 binding.imgB.setOnClickListner { clickBuyHandler() } binding.imgB.setImageResource(currentWatch.imgId) binding.price = price binding.volumn = volumn } private fun clickBuyHandler() { // update value of volumn when user click on the button to demonstrate he/she wanna buy it volumnAfterBuy-- binding.volumn = volumnAfterBuy showOtherWatch() } private fun showOtherWatch() { // TODO // for-in loop // use the data class called allGramin3C // retrieve the gramin3C data by creating a varibale calling allGramin3C[0] // see Anroid_Review_7 } // Menu to be inflated override fun onCreateOptionsMenu(menu: Menu): Boolean { menuInflater.inflate(R.menu.main_menu, menu) return super.onCreateOptionsMenu(menu) } // Items to be selected override fun onOptionsItemSelected(item: MenuItem): Boolean { // lambda // (itemId) -> {body} // {itemId -> body} when(item.itemId){ R,id.showMenuTouch -> showGarmin() } return super.onOptionsItemSelected(item) } // ShareCompat is a public class // its IntentBuilder is a constructor // then call its methods and properties // Intent // Exception Handler private fun showGarmin() { // Intent // setText(CharSequence text) // Set the literal text data to be sent as part of the share. // Question on getIntent() instead of .intent val showIntent = ShareCompat.IntentBuilder.from(this).setText(getString(R.string.share_text, price, volumn)).setType("text/plain").intent try { startActivity(showIntent) } catch(ex: ActivityNotFoundException) { Toast.makeText(this, getString(), Toast.LENGTH_LONG).show() } } } -
today’s tip (getString())
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today’s tip (field)
%1$d , the first filed that holds integer type variable
%2$s , the second field that holds string type varibale -
today’s tip (constructor)
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constructor can’t be called directly.
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constructor has no param.
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before instance is created, we use constructor instad to ref the members.
https://stackoverflow.com/questions/4506990/what-is-the-use-of-static-constructors
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today’s tip (CharSequence & String)
https://stackoverflow.com/questions/3600635/what-is-the-difference-between-charsequence-and-a-string
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android’s tip (IntentBuiler 意圖建構器)
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先導入模組 androidx.core.app.ShareCompat.IntentBuilder。
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我們使用此模組，目的是建造一個 IntentBuilder 的型別的實例。
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因建構子無法單獨使用，故先呼叫公共類別 SharCompat 與建構子 .IntenBuilder。
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建構子成立後，可呼叫內部成員方法，如
setText(@Nullable text: CharSequence?): IntentBuilder
setType(@Nullable mimeType: String?): IntentBuilder
setStream(@Nullable streamUri: Uri?): IntentBuilder
// HTML markup
setHtmlText(@Nullable htmlText: String?): IntentBuilder
from(@NonNull activity: Activity): IntentBuilder
startChooser(): void
getInetent(): Intent
setSubject(@Nullable subject: String?): IntentBuilder
setEmailBcc(@Nullable addresses: Array?): IntentBuilder
setEmailTo(@Nullable addressess: Array?): IntentBuilder
https://developer.android.com/reference/kotlin/androidx/core/app/ShareCompat.IntentBuilder
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android’s tip (Intent 意圖)
————Main2Activity.java——————–
//使用 putExtra(), getExtra() 夾帶資料
EditText et; et = fincdViewById(R.id.edit_text); // et.getText().toString() or getString(et) String Msg = et.getString(); Intent anotherIntent = new Intent(MainActivity.this, Main2Activity.class); anotherIntent.putExtra("I luv android since 2018", msg) // setResult(2, anotherIntent); startActivity(anotherIntent);————MainActivity.java———————–
// onCreate() Intent intent = new Intent(MainActivity.this, Main2Activity.class); startActivityForResult(intent, 2) // onActivityResult() // if requestCode ==2 String msg = data.getStringExtra(""); txv.setText(msg)https://medium.com/@skywing0527/android自學筆記-14-intent用法-範例練習-ad774d2f92ec
https://github.com/QueenieCplusplus/Android_Review_8
