How to create a button dynamically?

Question

I know that many people have asked about this, but my question has a difference:

I already have a layout in xml (using tabs), but I need to create buttons according to a reading of a string.

For example: The query returns four words. I need to create four buttons, that when clicked appear a toast with the word.

Attention: I don't know how many words will find.

The code would look something like:

    while (Content.indexOf("<glossary>") != -1) {
        Content = Content.substring(Content.indexOf("<glossary>") + 9);
        //create button with name "Content"
    }

Edit:

Look my new code for create just one Button:

    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.showphyto);
    intent = getIntent();
    Title = intent.getStringExtra("Title");
    Content = intent.getStringExtra("Content");
    setTitle(Title);
    //if(getIntent().getData().getQueryParameter("author") != null)
    TabSpec descritor;

    /************************** Tab General **************************/
    descritor = getTabHost().newTabSpec("tag1");
    descritor.setContent(R.id.General);

    Button myButton = new Button(ShowAllegationActivity.this);
    myButton.setText("test");
    LinearLayout myContainer = (LinearLayout) findViewById(R.id.General);
    myContainer.addView(myButton);

    descritor.setIndicator("General", getResources().getDrawable(R.drawable.icon));
    getTabHost().addTab(descritor);

    /************************** Tab 2 **************************/
    descritor = getTabHost().newTabSpec("tag2");
    descritor.setContent(R.id.Recipe);
    Teste = (TextView) findViewById(R.id.teste2);
    Teste.setText("Teste2");
    descritor.setIndicator("Tab2", getResources().getDrawable(R.drawable.icon));
    getTabHost().addTab(descritor);

    /************************** Tab3 3 **************************/
    descritor = getTabHost().newTabSpec("tag3");
    descritor.setContent(R.id.Related);
    Teste = (TextView) findViewById(R.id.teste3);
    Teste.setText("Teste3");
    descritor.setIndicator("Tab3", getResources().getDrawable(R.drawable.icon));
    getTabHost().addTab(descritor);

    getTabHost().setCurrentTab(0);

}

}

xml file:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TabHost android:id="@android:id/tabhost" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent">
    <LinearLayout android:id="@+id/linearLayout1" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical">
        <TabWidget android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:id="@android:id/tabs"></TabWidget>
        <FrameLayout android:layout_width="fill_parent" 
        android:layout_height="fill_parent" 
        android:id="@android:id/tabcontent">
            <LinearLayout android:layout_width="fill_parent" 
            android:layout_height="fill_parent" 
            android:id="@+id/General">
                    <TextView android:layout_width="fill_parent"
                    android:layout_height="wrap_content" 
                    android:id="@+id/teste" />
                    <LinearLayout android:layout_width="fill_parent" 
                    android:layout_height="fill_parent" 
                    android:id="@+id/General2">
                    </LinearLayout>
            </LinearLayout>
            <LinearLayout android:layout_width="fill_parent" 
            android:layout_height="fill_parent" 
            android:id="@+id/Recipe">
                    <TextView android:layout_width="fill_parent"
                    android:layout_height="wrap_content" 
                    android:id="@+id/teste2" />
            </LinearLayout>
            <LinearLayout android:layout_width="fill_parent" 
            android:layout_height="fill_parent" 
            android:id="@+id/Related">
                    <TextView android:layout_width="fill_parent"
                    android:layout_height="wrap_content" 
                    android:id="@+id/teste3" />
            </LinearLayout>
        </FrameLayout>
    </LinearLayout>
</TabHost>

MattDavis · Accepted Answer · 2012-05-11 19:58:13Z

4

You can create a button in code with:

Button myButton = new Button();
myButton.setLayoutParams(myLayoutParams);
myButton.setText(myText);

To make it display the Toast, add an onClickListener:

myButton.setOnClickListener(new View.OnClickListener()
                {
                    @Override
                    public void onClick(View view)
                    {
                        //The parameter view is the button that was clicked 
                        Toast.makeText(context, ((Button) view).getText(), Toast.LENGTH_LONG).show()
                        //TypeCasting to Button is important, because a normal View doesn't have a getText method
                    }
                });

Then, to add them to your screen, you'll need to have a container defined in xml to hold them, for example a LinearLayout. Get the LinearLayout with:

LinearLayout myContainer = findViewById(R.id.myButtonId); //Make sure you set the android:id attribute in xml

You'll probably want this code to be outside of your loop, perhaps just before it, so you're not getting the Layout on each iteration.

Then, in the loop, after your button is set up:

myContainer.addView(myButton);

Finally, a note about the myLayoutParams variable. When you set parameters for a view, they need to correspond to the parent view for your widget. So if you're putting the Button in a LinearLayout it would look like

//This will make LayoutParameters with layout_width="wrap_content" and layout_height="fill_parent"
LinearLayout.LayoutParams myLayoutParams = new LinearLayout.LayoutParams(
    LinearLayout.LayoutParams.WRAP_CONTENT, 
    LinearLayout.LayoutParams.FILL_PARENT);

You can also put this outside of your loop, too, and reuse it for each Button.

answered May 11, 2012 at 19:58

MattDavis

5,1782 gold badges25 silver badges35 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

Fabiano Palaoro Over a year ago

Hello Matt, thanks for reply. I could not, I edited the post with the complete code, you can tell me what's wrong? Thx!

Fabiano Palaoro Over a year ago

I need create a Button in xml?

MattDavis Over a year ago

You shouldn't need a button in xml. What is currently going wrong? Is the program crashing, or just not working how you intended? If it's crashing, post your logcat for the error. If not, it might be useful to see the "showphyto" xml file. Since it looks like you're using a tab layout, this tutorial from google may also provide some help developer.android.com/resources/tutorials/views/… Tabs are not set up like normal buttons, which may be part of your problem.

Fabiano Palaoro Over a year ago

Just not working my intended! I edited with the xml file. Look please.

MattDavis Over a year ago

Take a look at #4-6 on the link I posted in my previous comment. It looks like, rather than buttons, you use the TabHost to load a bunch of Tabs that fire off intents. The tabs are located inside your TabWidget and the intent is created in the FrameLayout. I've never used this particular layout before, but setting up your "buttons" the way the tabs are set up in #6 may help. What do you want your tabs to do once clicked? If it's just fire off a Toast, you may be better off using a less complicated layout.

|

Ostkontentitan · Accepted Answer · 2012-05-11 19:49:51Z

2

What you could do would be something like this:

    Button button = new Button(this);
    ViewGroup viewGroup = (ViewGroup) findViewById(R.id.container);

    viewGroup.addView(button);

I dont know your layout so i cant get more specific.

The ViewGroup would be your layout and it should have the id to be found by findByViewId.

In addition you would have to place the button were you want it to be.

answered May 11, 2012 at 19:49

Ostkontentitan

7,0306 gold badges56 silver badges72 bronze badges

Comments

Tarun · Accepted Answer · 2012-05-11 19:42:21Z

1

 while (Content.indexOf("<glossary>") != -1) {
    Content = Content.substring(Content.indexOf("<glossary>") + 9);
    //create button with name "Content"
    Button b = new Button(this);
    b.setText(Content);
    // add this new view to your parent layout
    parent.addView(b);

}

answered May 11, 2012 at 19:42

Tarun

13.8k8 gold badges44 silver badges57 bronze badges

Comments

Fishbreath · Accepted Answer · 2012-05-11 19:48:44Z

1

You'll want to include a layout in your XML to hold the buttons you add (you could do that dynamically, but it doesn't seem necessary). When you want to add a button, find that layout. You can then use ViewGroup.addView(View child) to add your buttons to the view hierarchy.

You'll also want to tell the system that the layout has changed, which you can do with the View.invalidate() method.

answered May 11, 2012 at 19:48

Fishbreath

4072 silver badges9 bronze badges

Comments

BenMorel · Accepted Answer · 2013-12-27 15:03:04Z

1

I changed the way to create tabs and it worked!

edited Dec 27, 2013 at 15:03

BenMorel

37k52 gold badges208 silver badges339 bronze badges

answered May 17, 2012 at 12:49

Fabiano Palaoro

2671 gold badge3 silver badges13 bronze badges

Collectives™ on Stack Overflow

How to create a button dynamically?

5 Answers 5

6 Comments

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

6 Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related