按屏幕大小设置dialog宽高

    public void setDialogSize(Dialog dg) {        Window dialogWindow = dg.getWindow();        WindowManager.LayoutParams lp = dialogWindow.getAttributes();// 获取对话框当前的参数值        dialogWindow.setGravity(Gravity.CENTER);//设置对话框屏幕居中        WindowManager m = getWindowManager();        Display d = m.getDefaultDisplay();// 获取屏幕宽、高用        lp.height = (int) (d.getHeight()*0.25);// 高度设置为屏幕的0.25        lp.width = (int) (d.getWidth() * 0.8);// 宽度设置为屏幕的0.8        dialogWindow.setAttributes(lp);    }