android 设置自定义dialog大小无效果

 public PicDialog create() {
            LayoutInflater inflater = (LayoutInflater) mActivity
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            final PicDialog dialog = new PicDialog(mActivity, R.style.customDialog);
            View layout = inflater.inflate(R.layout.view_pic_dialog, null);
		//先设置宽高，最后再setContentView

            layout.setMinimumWidth((int) (mActivity.getWindowManager()
                    .getDefaultDisplay().getWidth() * 0.8));//设置dialog的宽度


            dialog.addContentView(layout, new ViewGroup.LayoutParams(//设置dialog
                    ViewGroup.LayoutParams.WRAP_CONTENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT));
            dialog.setCancelable(true);

            if (!StringUtil.isEmptyOrNull(titleText)){
                ((TextView)layout.findViewById(R.id.tv_view_pic_dialog_title)).setText(titleText);
            }

            if (!StringUtil.isEmptyOrNull(topText)){
                TextView topTextView = ((TextView)layout.findViewById(R.id.tv_view_pic_dialog_top));
                topTextView.setText(topText);
                topTextView.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        positiveButtonClickListener.onClick(dialog,
                                1);
                    }
                });
            }

            if (!StringUtil.isEmptyOrNull(bomText)){
                TextView bomTextView = ((TextView)layout.findViewById(R.id.tv_view_pic_dialog_bom));
                bomTextView.setText(bomText);
                bomTextView.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        negativeButtonClickListener.onClick(dialog,
                                2);
                    }
                });
            }
            dialog.setContentView(layout);
            return dialog;
        }