以编程方式显示 ImageView

当用户单击按钮时，如何使 ImageView 出现在屏幕中间？我已将图像放在 res/drawable-文件夹中。

我一直在尝试使用下面的代码，但我不知道如何使 ImageView 出现：

 View v = new ImageView(getBaseContext());
 ImageView image; 
 image = new ImageView(v.getContext()); 
 image.setImageDrawable(v.getResources().getDrawable(R.drawable.gameover));

Thanks!

//LinearLayOut Setup
LinearLayout linearLayout= new LinearLayout(this);
linearLayout.setOrientation(LinearLayout.VERTICAL);

linearLayout.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT));

//ImageView Setup
ImageView imageView = new ImageView(this);

//setting image resource
imageView.setImageResource(R.drawable.play);

//setting image position
imageView.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, 
LayoutParams.WRAP_CONTENT));

//adding view to layout
linearLayout.addView(imageView);
//make visible to program
setContentView(linearLayout);