如何在彼此之间动态添加按钮

Question

For the last few days, I've been trying to figure out how to make a list of buttons that are below each other, and fill the entire width of the screen dynamically. So for example:

(I cheaply just took an pre-existing screen shot that had one button and edited it in paint.net to make it look like the buttons are stacked.)

So, essentially, I have a list of strings from R that include the button's names and I need to list them like that. I've been looking around and if I did find anything it was outdated (and didn't work)

This is what I have so far (its a little messy because it contains many attempts at making this happen)

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

    Field[] fields = R.raw.class.getFields();

    for(int count=0; count < fields.length; count++){

        String filename = fields[count].getName();

        try {
            Button button = new Button(this);
            button.setText(filename);
            button.setId(startID + 1 + count); //this variable is offscreen
            button.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    //finish later
                }

            });
            button.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT));

            layout.addView(button);

        } catch (Exception e) {
            Toast.makeText(MainActivity.this, "Exception.", Toast.LENGTH_LONG).show();
        }
    }

(this is in onCreate() fyi)

So, if anyone has any solutions/ideas on how I can do this, please share. I'm fairly new to creating android applications.

Answer 1

Java

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

    String[] items = {"item 1", "item 2", "item 3", "item 4", "item 5"};

    for (int i = 0; i < items.length; i++) {
        Button btn = new Button(this);
        btn.setText(items[i]);
        btn.setId(i);
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
                ViewGroup.LayoutParams.MATCH_PARENT,
                ViewGroup.LayoutParams.WRAP_CONTENT);

        params.setMargins(10, 10, 10, 10);
        btn.setLayoutParams(params);
        layout.addView(btn);
    }

Xml

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

Answer 2

A simple example

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="match_parent">

    <LinearLayout
        android:id="@+id/linear"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:orientation="vertical">
    </LinearLayout>

</RelativeLayout>

Java:

String[] names = { "button1", "button2", "button3", "button4" };

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

for (int i = 0; i < 4; i++) {
    Button button = new Button(this);
    button.setText(names[i]);
    button.setId(i);
    button.setBackgroundColor(Color.BLUE);

    LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
            LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
    params.setMargins(20, 0, 20, 20); // (left, top, right, bottom)
    button.setLayoutParams(params);

    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            // finish later
        }

    });
    layout.addView(button);

Answer 3

You might be better off learning how to use ListViews , and using Adapters to populate the ListView with Buttons containing the data from your array.

Bear in mind that for the solution you and Sajith Sageer offered, when there are too many buttons created, the buttons will extend past the screen, making them unreachable unless you wrap the LinearLayout in a ScrollView.