Kotlin: How to get and set a text to TextView in A

问题:

I'm newbie.

I want to change text of TextView While click on it.

My code:

val text: TextView = findViewById(R.id.android_text) as TextView
    text.setOnClickListener {
        text.setText(getString(R.string.name))
    }

Output: I got the output but showing use property access syntax.

Can anyone tell me how to do it?

Thanks in advance.

回答1:

In kotlin don't use getters and setters as like in java.The correct format of the kotlin is given below.

val textView: TextView = findViewById(R.id.android_text) as TextView
textView.setOnClickListener {
    textView.text = getString(R.string.name)
}

To get the values from the Textview we have to use this method

 val str: String = textView.text.toString()

 println("the value is $str")

回答2:

just add below line and access direct xml object

import kotlinx.android.synthetic.main.activity_main.*

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        txt_HelloWorld.text = "abc"
    }

replace activity_main according to your XML name

回答3:

Find the text view from the layout.

val textView : TextView = findViewById(R.id.android_text) as TextView

Setting onClickListener on the textview.

textview.setOnClickListener(object: View.OnClickListener {
    override fun onClick(view: View): Unit {
        // Code here.
        textView.text = getString(R.string.name)
    }
})

Argument parentheses can be omitted from View.setOnClickListener if we pass a single function literal argument. So, the simplified code will be:

textview.setOnClickListener {
    // Code here.
    textView.text = getString(R.string.name)
}

回答4:

Use:

val textView: TextView = findViewById(R.id.android_text) as TextView
textView.setOnClickListener {
    textView.text = getString(R.string.name)
}

Or:

you can annotate every call site with @Suppress("UsePropertyAccessSyntax"), but that’s ugly.

回答5:

  <TextView
        android:id="@+id/usage"
        android:layout_marginTop="220dip"
        android:layout_marginLeft="45dip"
        android:layout_marginRight="15dip"
        android:typeface="serif"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Google "
        android:textColor="#030900"/>


usage.text="hello world"

回答6:

import kotlinx.android.synthetic.main.MainActivity.*

class Mainactivity : AppCompatActivity() {


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.MainActivity)

        txt.setText("hello Kotlin")

    }

}

回答7:

val text: TextView = findViewById<TextView>(R.id.text_id) as TextView

回答8:

findViewById(R.id.android_text) does not need typecasting.

回答9:

The top post has 'as TextView' appended on the end. You might get other compiler errors if you leave this on. The following should be fine.

val text: TextView = findViewById(R.id.android_text) as TextView

Where 'android_text' is the ID of your textView