How do I programmatically add buttons into layout

Question

How to create a list of buttons one by one in several lines? I made this:

LinearLayout layout = (LinearLayout) findViewById(R.id.linear_layout_tags);
    for (int i = 1; i < 10; i++) {
        Button btnTag = new Button(this);
        btnTag.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
        btnTag.setText("Button " + i);
        btnTag.setId(i);
        layout.addView(btnTag);
        ((Button) findViewById(i)).setOnClickListener(this);
    }

and got only one line:

How to go to the next line programmatically?

Answer 1

This will help

private void addingParticipantinFrame() {
        TableRow row;
        final int screenWidth = dpToPx(getResources().getConfiguration().screenWidthDp);
        add_button_particiapants.setVisibility(View.VISIBLE);
        if (arrrItemSelcted != null && arrrItemSelcted.size() > 0) {

            arrrItemSelcted.remove(0);
            int i = 0;
            int j = 0;
            int width = (screenWidth - (arrrItemSelcted.size())*4)/arrrItemSelcted.size();

            while (i<arrrItemSelcted.size()) {
                j = i + 4;
                row = new TableRow(mParentActivity);
                TableRow.LayoutParams lp = new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.WRAP_CONTENT);
                row.setLayoutParams(lp);
                row.setWeightSum(4);
                while ((i<j)&&(i<arrrItemSelcted.size())) {
                    Button iBtn = new Button(mParentActivity);
                    iBtn.setGravity(Gravity.CENTER_HORIZONTAL);
                    iBtn.setMinimumWidth(100);//I set 100px for minimunWidth.
                    iBtn.setWidth(width);
                    iBtn.setText(Integer.toString(i + 1));
                    iBtn.setId(i + 1);
                    row.addView(iBtn, 4 + i - j);
                    i++;
                }
                add_button_particiapants.addView(row);
            }



            }
        }

Answer 2

This is like 1 answer, but without the need to make a XML file.

public class mainActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        LinearLayout layout = new LinearLayout(this);
        layout.setOrientation(LinearLayout.VERTICAL);  //Can also be done in xml by android:orientation="vertical"

        for (int i = 0; i < 3; i++) {
            LinearLayout row = new LinearLayout(this);
            row.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));

            for (int j = 0; j < 4; j++) {
                Button btnTag = new Button(this);
                btnTag.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
                btnTag.setText("Button " + (j + 1 + (i * 4 )));
                btnTag.setId(j + 1 + (i * 4));
                row.addView(btnTag);
            }

            layout.addView(row);
        }
        setContentView(layout);
        //setContentView(R.layout.main);
    }
} 

Answer 3

The issue is that your buttons are not going to automatically wrap to the next part of the screen. You have to specifically tell Android how you want your Views to be positioned. You do this using ViewGroups such as LinearLayout or RelativeLayout.

LinearLayout layout = (LinearLayout) findViewById(R.id.linear_layout_tags);
layout.setOrientation(LinearLayout.VERTICAL);  //Can also be done in xml by android:orientation="vertical"

        for (int i = 0; i < 3; i++) {
        LinearLayout row = new LinearLayout(this);
        row.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));

        for (int j = 0; j < 4; j++) {
            Button btnTag = new Button(this);
            btnTag.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT));
            btnTag.setText("Button " + (j + 1 + (i * 4)));
            btnTag.setId(j + 1 + (i * 4));
            row.addView(btnTag);
        }

        layout.addView(row);
    }

I'm assuming that R.id.linear_layout_tags is the parent LinearLayout of your XML for this activity.

Basically what you're doing here is you're creating a LinearLayout that will be a row to hold your four buttons. Then the buttons are added and are each assigned a number incrementally as their id. Once all of the buttons are added, the row is added to your activity's layout. Then it repeats. This is just some pseudo code but it will probably work.

Oh and next time be sure to spend more time on your question...

https://stackoverflow.com/questions/how-to-ask

Answer 4

I had the problem, that the number of views to be placed on the UI was set during runtime. So I decided that I want only four views in one row and adapted the code above accordingly. Also, I always filled up the last row with invisible edit texts so that the views in the last row also had the same width as the views in the row above:

        // 1.0f is the weight!
        LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT, 1.0f);
        layoutParams.setMarginEnd(10);

        for (int i = 0; i < Math.ceil(discipline.getSeries_count() / 4.0); i++) {
            LinearLayout layoutRow = new LinearLayout(MyActivity.this);
            layoutRow.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));

            // add only four edit texts to row and move to next line afterwards
            for (int j = 0; j < 4; j++) {
                etSeries = new EditText(MyActivity.this);
                etSeries.setInputType(InputType.TYPE_CLASS_NUMBER);
                int iIndex = (j + 1 + (i * 4));
                etSeries.setText(getResources().getString(R.string.series) + " " + iIndex);
                etSeries.setId(iIndex);
                etSeries.setId(i);
                etSeries.setSelectAllOnFocus(true);
                etSeries.setLayoutParams(layoutParams);
                etSeries.setVisibility(iIndex > discipline.getSeries_count() ? View.INVISIBLE : View.VISIBLE);
                layoutRow.addView(etSeries);
            }
            layoutSeries.addView(layoutRow);
        }