Android - Set text to TextView

Question

I'm currently learning some android for a school project and I can't figure out the way to set text dynamically to a TextView.

Here is my code:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_enviar_mensaje);
    err = (TextView)findViewById(R.id.texto);
    err.setText("Escriba su mensaje y luego seleccione el canal.");
}

This is currently not working and I can't find a way to make it work...

Any help will be much apretiated... Thank you for the time, José.

EDIT: Here is the activity_enviar_mensaje.xml

<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="wrap_content"
    ...
    tools:context=".EnviarMensaje" >
    ...
    <TextView
        android:id="@+id/texto"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/listaVista"
        android:layout_alignParentBottom="true"
        android:layout_alignRight="@+id/listaVista"
        android:text="TextView" />
    ...
</RelativeLayout>

By not working I mean the text shown does not change at any moment...

Answer 1

Well, @+id/listaVista ListView is drawn after @+id/texto and on top of it. So change in ListView from:

android:layout_below="@+id/editText1"

to:

android:layout_above="@+id/texto"

Also, since the list is drawn after textview, I find it dangerous to have android:layout_alignRight="@+id/listaVista" in TextView. So remove it and find another way of aligning.

EDIT Taking a second look at your layout I think this is what you really want to have:

<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="wrap_content"
    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=".EnviarMensaje" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:text="Escriba el mensaje y luego clickee el canal a ser enviado"
        android:textSize="20sp" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView1"
        android:layout_alignRight="@+id/textView1"
        android:layout_below="@+id/textView1"
        android:ems="10"
        android:inputType="text" />

    <TextView
        android:id="@+id/texto"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/listaVista"
        android:layout_alignParentBottom="true"
        android:text="TextView" />

    <ListView
        android:id="@+id/listaVista"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/texto"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/editText1" >
    </ListView>

</RelativeLayout>

Answer 2

I had a similar problem. It turns out I had two TextView objects with the same ID. They were in different view files and so Eclipse did not give me an error. Try to rename your id in the TextView and see if that does not fix your problem.

Answer 3

in your activity_main.xml paste this code:

            <TextView
                 android:id="@+id/name"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:layout_alignParentLeft="true"
                 android:layout_alignParentTop="true"
                 android:layout_marginLeft="19dp"
                 android:layout_marginTop="43dp"
                 android:text="@string/name" />

and go to res folder->values->strings.xml paste the below code with the code that already exists:

          <string name="name">Escriba su mensaje y luego seleccione el canal.</string>

the above code means that you have created a textview with id:name(android:id="@+id/name") and assigned that textview to a string with an identifier name(android:text="@string/name") in strings.xml your using that identifier name to assign the text,

Answer 4

Try This:

TextView err = (TextView)findViewById(R.id.text);

Ensure you import TextView.

Answer 5

In layout file.

<TextView
   android:id="@+id/myTextView"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:text="Some Text"
   android:textSize="18sp"
   android:textColor="#000000"/>

In Activity

TextView myTextView = (TextView)findViewById(R.id.myTextView);
myTextView.setText("Hello World!");

Answer 6

In XML file,

<TextView
       android:id="@+id/textview"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:text="My Name"
       android:textColor="#cccccc"/>

In Java Activity file,

public class MainActivity1 extends Activity
 {
   TextView t1;
   public void onCreate(Bundle onSavedInstance)
      {
         setContentView(R.layout.xmlfilename);
          t1 = (TextView)findViewbyId(R.id.textview);
      }
 }