android 使用Activity类布局时怎样让图片居中

1、通过xml布局显示，在加载图片的View加入以下属性让整个View居中

a、线性布局(LinearLayout)

android:layout_gravity=”center”

b、相对布局(RelativeLayout)

android:layout_centerInParent=”true”

2、通过java代码动态实现

a、线性布局(LinearLayout)

LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(

LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);

params.gravity = Gravity.CENTER;

view.setLayoutParams(params);

b、相对布局(RelativeLayout)

RelativeLayout.LayoutParams params = new RelativeLayout().LayoutParams(

LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);

params.addRule(RelativeLayout.CENTER_IN_PARENT,RelativeLayout.TRUE);

view.setLayoutParams(params);