实现背景透明,宽度可控的Dialog

LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);        View view = inflater.inflate(R.layout.dialog_activity_reward,null);        ImageView image_close = (ImageView) view.findViewById(R.id.dialog_activity_close);        image_close.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                myDialog.dismiss();            }        });        AlertDialog.Builder builder = new AlertDialog.Builder(this);        builder.setView(view);        myDialog = builder.create();        myDialog.setCancelable(false);        Window dialogWindow = myDialog.getWindow();        dialogWindow.setBackgroundDrawableResource(R.color.transparent);        WindowManager m = getWindowManager();        Display defaultDisplay = m.getDefaultDisplay();        WindowManager.LayoutParams lp = dialogWindow.getAttributes();        lp.width = (int) (defaultDisplay.getWidth() * 0.90);        dialogWindow.setAttributes(lp);