【1】
public void addView(View child) { addView(child, -1); }【2】
public void addView(View child, int index) { if (child == null) { throw new IllegalArgumentException("Cannot add a null child view to a ViewGroup"); } LayoutParams params = child.getLayoutParams(); if (params == null) { params = generateDefaultLayoutParams(); if (params == null) { throw new IllegalArgumentException("generateDefaultLayoutParams() cannot return null"); } } addView(child, index, params); }【3】
@Override protected LayoutParams generateDefaultLayoutParams() { if (mOrientation == HORIZONTAL) { return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); } else if (mOrientation == VERTICAL) { return new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT); } return null; }