如何使图像视图在水平滚动视图内的线性布局中居中？

Question

Example Diagram

I have ImageViews programmatically being added to the linear layout and want these centered in the linear layout, but the layout itself aligned to the left.

Answer 1

And in your code, obtain your LinearLayout:

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

Define a common LayoutParams object:

  LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
  LinearLayout.LayoutParams.WRAP_CONTENT,
  LinearLayout.LayoutParams.WRAP_CONTENT);

And add your ImageViews to your LinearLayout with a for loop:

for (int i = 0; i < imagesToAdd.size(); i++) {
 ImageView imgView = new ImageView(this);
 imgView.setImageResource("yourResourceID" + i);
 imgView.setLayoutParams(layoutParams);
 yourLinearLayout.addView(imgView);
}

Answer 2

Create a Layout with a HorizontalScrollView as a root view and a LinearLayout as a child

To center images, make sure to use android:gravity="center" in the LinearLayout

<?xml version="1.0" encoding="utf-8"?>
<HorizontalScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/rootlayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:scrollbars="horizontal">

    <LinearLayout
        android:id="@+id/linearlayout"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:gravity="center"
        android:orientation="horizontal">

    </LinearLayout>

</HorizontalScrollView>

And to add images programmatically, inflate the LinearLayout and use addView() method

public class MainActivity extends AppCompatActivity {

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

        LinearLayout linearLayout = findViewById(R.id.linearlayout);

        linearLayout.addView(getImage(R.drawable.image1));
        linearLayout.addView(getImage(R.drawable.image2));
        linearLayout.addView(getImage(R.drawable.image3));

    }

    ImageView getImage(int drawable) {
        ImageView image = new ImageView(this);
        image.setLayoutParams(new 
                LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 
                                          ViewGroup.LayoutParams.WRAP_CONTENT));
        image.setImageResource(drawable);
        return image;
    }

}