Android Adventures-Development Tips-Part 4

Dec. 28 Apps and Tools no comments

How to remove the divider in a ListView?

android:divider="@null"

1	android:divider="@null"

What if my text doesn’t fit in a TextView?

android:ellipsize="marquee" -– it will scroll horizontally
android:ellipsize="end" – it will display “…”

1 2	android:ellipsize="marquee" -– it will scroll horizontally android:ellipsize="end" – it will display “…”

How to return values from to the caller Activity?

Main Activity:

{
    val intent = Intent(this, SecondActivity::class.java)
    intent.putExtra("someparametertosendkey", true)

    // call the activity like this
    startActivityForResult(intent, "akeytoidentifytheresult")
}

// This method is called when the second activity finishes
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent) {
    super.onActivityResult(requestCode, resultCode, data)

// Check that it is the SecondActivity with an OK result
    if (requestCode != USE_REGEX_RESULT_KEY) return

   if (resultCode == Activity.RESULT_OK) {

    // Get String data from Intent
    someview1.setText(data.getStringExtra("aresultfromsecondactivity1"))
    someview2.setText(data.getStringExtra("aresultfromsecondactivity2"))
    }
}
...
//
// Second Activity:
//

    // return the result
    val intent = Intent()
    intent.putExtra("aresultfromsecondactivity1", selectedItem.expression)
    intent.putExtra("aresultfromsecondactivity2", selectedItem.example)
    setResult(Activity.RESULT_OK, intent)
    finish()

{

val intent = Intent(this, SecondActivity::class.java)

intent.putExtra("someparametertosendkey", true)

// call the activity like this

startActivityForResult(intent, "akeytoidentifytheresult")

}

// This method is called when the second activity finishes

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent) {

super.onActivityResult(requestCode, resultCode, data)

// Check that it is the SecondActivity with an OK result

if (requestCode != USE_REGEX_RESULT_KEY) return

if (resultCode == Activity.RESULT_OK) {

// Get String data from Intent

someview1.setText(data.getStringExtra("aresultfromsecondactivity1"))

someview2.setText(data.getStringExtra("aresultfromsecondactivity2"))

}

...

// Second Activity:

// return the result

val intent = Intent()

intent.putExtra("aresultfromsecondactivity1", selectedItem.expression)

intent.putExtra("aresultfromsecondactivity2", selectedItem.example)

setResult(Activity.RESULT_OK, intent)

finish()

Highlight an item in a ListView

&lt;ListView
         android:id="@+id/regExListView"
         android:layout_width="match_parent"
         android:choiceMode="singleChoice" // choose 1 item only
         android:dividerHeight="3dp" // the space between items
         android:layout_height="wrap_content"&gt;

<ListView

android:id="@+id/regExListView"

android:layout_width="match_parent"

android:choiceMode="singleChoice" // choose 1 item only

android:dividerHeight="3dp" // the space between items

android:layout_height="wrap_content">

// and in the code if you want to only change the background
for (a in 0 until parent.childCount) {
    val item = parent.getChildAt(a)
    item.setBackgroundColor(Color.TRANSPARENT)
}

view.setBackgroundColor(resources.getColor(R.color.colorPrimaryUltraLight))

// and in the code if you want to only change the background

for (a in 0 until parent.childCount) {

val item = parent.getChildAt(a)

item.setBackgroundColor(Color.TRANSPARENT)

}

view.setBackgroundColor(resources.getColor(R.color.colorPrimaryUltraLight))

Tags: android, Development, tips

José da Cruz

@it.blog

Android Adventures-Development Tips-Part 4

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