lp3.gravity = Gravity.RIGHT怎么不起作用呢？

[izhangxueyonghotmail]

请问
LinearLayout mvLine = new LinearLayout(this.getBaseContext());
mvLine.setClickable(true);
mvLine.setOnClickListener(detailListener);
// mvLine.inflate(context, resource, root)
// mvLine.addFocusables(views, direction)
mvLine.setBackgroundDrawable(this.getBaseContext()
.getResources().getDrawable(R.drawable.list_bg));
mvLine.setOrientation(android.widget.LinearLayout.HORIZONTAL);
ImageButton ib = new ImageButton(this.getBaseContext());
ib.setBackgroundDrawable(this.getResources().getDrawable(
R.drawable.arrow));

ib.setOnClickListener(toplayClickListener);
ib.setAdjustViewBounds(true);
LinearLayout.LayoutParams lp3 = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

lp3.topMargin = 39;
lp3.rightMargin = 20;
lp3.gravity = Gravity.RIGHT;
mvLine.addView(ib, lp3);