我在写软件时希望在原有布局上面显示一张透明背景的图片做装饰，然而addView时总是程序停止运行……希望有高手告诉我哪里错了……
代码
private WindowManager wm = null;
private WindowManager.LayoutParams wmlp = null;
private ImageView iv1 = null;
在oncreate中：
iv1 = new ImageView(getApplicationContext());
iv1.setImageResource(R.drawable.forcefeeding_nom);
wm = (WindowManager)getApplicationContext().getSystemService("window");
wmlp = new WindowManager.LayoutParams();
wmlp.type = wmlp.TYPE_APPLICATION;
wmlp.format = PixelFormat.RGBA_8888;
wmlp.flags = wmlp.FLAG_NOT_TOUCH_MODAL|wmlp.FLAG_NOT_FOCUSABLE|wmlp.FLAG_NOT_TOUCHABLE|wmlp.FLAG_LAYOUT_NO_LIMITS;
wmlp.gravity = Gravity.LEFT | Gravity.TOP;
wmlp.x = getResources().getDimensionPixelSize(R.dimen.Startx);
wmlp.y = getResources().getDimensionPixelSize(R.dimen.Starty);
wmlp.width = getResources().getDimensionPixelSize(R.dimen.PicWidthdp);
wmlp.height = getResources().getDimensionPixelSize(R.dimen.PicHeightdp);
wm.addView(iv1,wmlp);//这里出错，FC
学生党用手机编译运行的，看不到错误信息，只能一行行排查发现运行到addview就挂了……