Como adicionar um botão dinamicamente no Android?

Como adicionar um botão dinamicamente no Android?

Button myButton = new Button(this);
myButton.setText("Push Me");

LinearLayout ll = (LinearLayout)findViewById(R.id.buttonlayout);
LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
ll.addView(myButton, lp);

Dê uma olhada neste exemplo

tente isto:

for (int i = 1; i <= 20; i++) {
    LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
            LinearLayout.LayoutParams.MATCH_PARENT,
            LinearLayout.LayoutParams.WRAP_CONTENT);
    Button btn = new Button(this);
    btn.setId(i);
    final int id_ = btn.getId();
    btn.setText("button " + id_);
    btn.setBackgroundColor(Color.rgb(70, 80, 90));
    linear.addView(btn, params);
    btn1 = ((Button) findViewById(id_));
    btn1.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {
            Toast.makeText(view.getContext(),
                    "Button clicked index = " + id_, Toast.LENGTH_SHORT)
                    .show();
        }
    });
}

Experimente isto:

LinearLayout ll = (LinearLayout)findViewById(R.id.layout);

Button btn = new Button(this);
btn.setText("Manual Add");
btn.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
ll.addView(btn);

tente isso

private void createLayoutDynamically(int n) {

    for (int i = 0; i < n; i++) {
        Button myButton = new Button(this);
        myButton.setText("Button :"+i);
        myButton.setId(i);
        final int id_ = myButton.getId();

        LinearLayout layout = (LinearLayout) findViewById(R.id.myDynamicLayout);
        layout.addView(myButton);

        myButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                Toast.makeText(DynamicLayout.this,
                        "Button clicked index = " + id_, Toast.LENGTH_SHORT)
                        .show();
            }
        });
    }

for (int k = 1; k < 100; k++) {
    TableRow row = new TableRow(this);

    innerloop:
    for (int l = 1; l < 4; l++) {
        btn = new Button(this);
        TableRow.LayoutParams tr = new TableRow.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
        layout.setWeightSum(12.0f);
        tr.weight = 0;
        btn.setLayoutParams(tr); 
        btn.setTextColor(a);
        btn.setHeight(150);

        btn.setWidth(150);
        btn.setId(idb);
        btn.setText("Button " + idb);
        row.addView(btn);
    }
}

Tente este código

 Button btn=new Button(this);
btn.setId(btn);
btn.setBackgroundResource(R.drawable.image);
btn.setMinimumHeight(150);
btn.setMinimumWidth(150);
Relativelayout.addView(btn); 

Experimente este código. Vai funcionar bem ..

public class DynamicViewsActivity extends Activity {

Button button;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //setContentView(R.layout.activity_dynamic_views);
    ScrollView scrl=new ScrollView(this);
    final LinearLayout ll=new LinearLayout(this);
    ll.setOrientation(LinearLayout.HORIZONTAL);
    LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
            LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
    layoutParams.setMargins(100, 500, 100, 200);
    scrl.addView(ll);
    Button add_btn=new Button(this);
    add_btn.setText("Click Here");

    ll.addView(add_btn, layoutParams);


    final Context context = this;

    add_btn.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            Intent intent = new Intent(context, App2Activity.class);
            startActivity(intent);
        }
    });
    this.setContentView(scrl);
}
}

Verifique isso.

LinearLayout ll_Main  = new LinearLayout(getActivity());
LinearLayout ll_Row01 = new LinearLayout(getActivity());
LinearLayout ll_Row02 = new LinearLayout(getActivity());

ll_Main.setOrientation(LinearLayout.VERTICAL);
ll_Row01.setOrientation(LinearLayout.HORIZONTAL);
ll_Row02.setOrientation(LinearLayout.HORIZONTAL);

final Button button01    = new Button(getActivity());
final Button button02    = new Button(getActivity());   
final Button button03    = new Button(getActivity());
final Button button04    = new Button(getActivity());

ll_Row01.addView(button01);
ll_Row01.addView(button02);

ll_Row02.addView(button03);
ll_Row02.addView(button04);

ll_Main.addView(ll_Row01);
ll_Main.addView(ll_Row02);

button04.setVisibility(View.INVISIBLE);
button04.setVisibility(View.VISIBLE);

Tente seguir o código.

LinearLayout layout = (LinearLayout) findViewById(R.id.llayout); 
layout.setOrientation(LinearLayout.VERTICAL);

Button btn = new Button(this);
btn.setText("Button1");

layout.add(btn);

btn = new Button(this);
btn.setText(Button2);
layout.add(btn);

assim, você adiciona botões de acordo com seus requisitos.

public void add_btn() {

    lin_btn.setWeightSum(3f);
    for (int j = 0; j < 3; j++) {
        LinearLayout.LayoutParams params1 = new LinearLayout.LayoutParams(
                LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
        params1.setMargins(10, 0, 0, 10);
        params1.weight = 1.0f;

        LinearLayout ll;
        ll = new LinearLayout(this);
        ll.setGravity(Gravity.CENTER_VERTICAL);
        ll.setOrientation(LinearLayout.HORIZONTAL);
        ll.setLayoutParams(params1);

        final Button btn;
        btn = new Button(DynamicActivity.this);

        btn.setText("A"+(j+1));
        btn.setTextSize(15);
        btn.setId(j);
        btn.setPadding(10, 8, 10, 10);

        ll.addView(btn);

        lin_btn.addView(ll);


        btn.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {

                if(v.getId()==0)
                {
                    txt_text.setText("Hii");
                }else if(v.getId()==1)
                {
                    txt_text.setText("hello");
                }else if(v.getId()==2)
                {
                    txt_text.setText("how r u");
                }



            }
        });
    }

}

Na verdade, adiciono ao arquivo de layout xml qualquer coisa que possa ser usada! Então, a partir do código-fonte da Activity específica, pego o objeto por seu id e "brinco" com o método de visibilidade.

Aqui está um exemplo:

((Spinner)findViewById(R.id.email_spinner)).setVisibility(View.GONE);

Usei este código (ou muito semelhante) para adicionar vários TextViews a um LinearLayout:

// Quick & dirty pre-made list of text labels...
String names[] = {"alpha", "beta", "gamma", "delta", "epsilon"};
int namesLength = 5;

// Create a LayoutParams...
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
    LinearLayout.LayoutParams.WRAP_CONTENT, 
    LinearLayout.LayoutParams.FILL_PARENT);

// Get existing UI containers...
LinearLayout nameButtons = (LinearLayout) view.findViewById(R.id.name_buttons);
TextView label = (TextView) view.findViewById(R.id.master_label);

TextView tv;

for (int i = 0; i < namesLength; i++) {
    // Grab the name for this "button"
    final String name = names[i];

    tv = new TextView(context);
    tv.setText(name);

    // TextViews CAN have OnClickListeners
    tv.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            label.setText("Clicked button for " + name); 
        }
    });

    nameButtons.addView(tv, params);
}

A principal diferença entre este e o código de dicklaw795 é que ele não define () e recupera () o ID de cada TextView - achei desnecessário, embora possa precisar dele para identificar posteriormente cada botão em uma rotina de tratamento comum ( por exemplo, um chamado por onClick () para cada TextView).

Button btn = new Button(this);
btn.setText("Submit");
LinearLayout linearLayout = (LinearLayout)findViewById(R.id.buttonlayout);
LayoutParams buttonlayout = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
linearLayout.addView(btn, buttonlayout);

Button myButton = new Button(this);
myButton.setId(123);
myButton.setText("Push Me");


LinearLayout ll = (LinearLayout)findViewById(R.id.buttonlayout);
LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
ll.addView(myButton, lp);
 myButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                Toast.makeText(DynamicLayout.this,
                        "Button clicked index = " + id_, Toast.LENGTH_SHORT)
                        .show();
            }
        });

Se você deseja adicionar botões dinamicamente, tente o seguinte:

public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main2);
    for (int i = 1; i <= 5; i++) {
        LinearLayout layout = (LinearLayout) findViewById(R.id.myLinearLayout);
        layout.setOrientation(LinearLayout.VERTICAL);
        Button btn = new Button(this);
        btn.setText("    ");
        layout.addView(btn);
    }

}

Você pode criar um layout base para o botão e alterar dinamicamente apenas o que é específico, como este projeto que fiz para executar diferentes exercícios de um curso de design de material que estou fazendo:

Neste exemplo, eu uso um AppCompatButton pré-configurado:

layout_base_button.xml

<android.support.v7.widget.AppCompatButton
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/btn_base"
    android:layout_width="200dp"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:layout_marginTop="8dp"
    style="@style/RaisedButton"
    >

</android.support.v7.widget.AppCompatButton>


<style name="RaisedButton" parent="Widget.AppCompat.Button.Colored">
    <item name="android:textSize">11sp</item>
    <item name="android:textStyle">bold</item>
</style>

E no MainActivitycriei algumas instâncias e alterei o que preciso, como o texto do botão e o evento onClick:

<ScrollView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="udemy.android.materialdesign.MainActivity">

    <LinearLayout
        android:id="@+id/base_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        >

    </LinearLayout>


</ScrollView>



public class MainActivity extends AppCompatActivity {


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        LinearLayout baseLayout = findViewById(R.id.base_layout);

        baseLayout.addView(createButton("TextFields", baseLayout,
                view -> startActivity(createIntent(TextFieldsActivity.class))
        ));

        baseLayout.addView(createButton("Buttons", baseLayout,
                view -> startActivity(createIntent(ButtonsActivity.class))
        ));

        baseLayout.addView(createButton("Toolbar", baseLayout,
                view -> startActivity(createIntent(ToolbarActivity.class))
        ));

    }

    private View createButton(String text, LinearLayout baseLayout, View.OnClickListener onClickEvent) {
        View inflated = LayoutInflater.from(this).inflate(R.layout.layout_base_button, baseLayout, false);
        AppCompatButton btnBase = inflated.findViewById(R.id.btn_base);

        btnBase.setText(text);
        btnBase.setOnClickListener(onClickEvent);
        return btnBase;
    }

    private Intent createIntent(Class<?> cls) {
        return new Intent(this, cls);
    }
}

Desculpe por estar atrasado...

Por mainactivity.xmlescrito:

<Button
    android:id="@+id/search"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Search" 
    android:visibility="invisible"/>

Por main.javaescrito:

Button buttonSearch;
buttonSearch = (Button)findViewById(R.id.search);
buttonSearch.setVisibility(View.VISIBLE);