Error in Android Studio

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Error in Android Studio

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#1 by (2 votes)
#2 by (1 votes)
#3 by (0 votes)

1

I am developing an application in Android Studio but at the time of executing it by the emulator I am getting the following error:

Error: can not find symbol variable fab

FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        Snackbar.make(
            view,
            "Replace with your own action",
            Snackbar.LENGTH_LONG
        ).setAction("Action", null).show();
    }
});

java android android-layout android-studio

asked by FABIAN AGUILAR 11.03.2017 в 14:53

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3 answers

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score 2 · Answer 1

Your problem is that you do not define the variable, you should do something like this:

// Aquí debes definir la variable, así:
FloatingActionButton fab1;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    fab1 = (FloatingActionButton) findViewById(R.id.fab);

    fab1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });

And in your layout :

   <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_launcher"
        fab:fab_label="Nombre"
        fab:fab_size="mini"
        android:clickable="false" />

score 1 · Answer 2

As UserNameYo says, you must declare your control variable. Also, I agree that you need to add your import well. I recommend you the following way:

Add the following line in your .gradle file in Android Studio in the dependencies part.

compile 'com.android.support:design:25.1.0'

By the time you add this line at the top of the code in the file, a yellow line will appear and on your right a link that will say Sync Now . Your project will be synchronized, wait for it to end.

Finally you add the following in Layout :

<android.support.design.widget.FloatingActionButton
    android:id="@+id/floatingActionButton"
    android:layout_width="250dp"
    android:layout_height="250dp"
    android:clickable="true"
    app:srcCompat="@android:drawable/ic_menu_add"/>

score 0 · Answer 3

Also before running your application you can see the error:

The problem is that within the layout that you load by means of setContentView() that is generally activity_main.xml , there is no element with id fab . Secure these by loading the container layout.

Add it so you can find a reference of FloatingActionButton .