Android 蒙层效果的实现

apk在第一次进入时 ，在主界面蒙上一层半透明的阴影效果，阴影上会突出显示说明主界面上的一些控件或文字。

直接上代码：

// 蒙层
public void mengcengDialog() {
final Dialog dialog = new Dialog(getActivity(), R.style.custom_dialog);
TextView textView = new TextView(getActivity());
textView.setText(getString(R.string.isFirstShopHint));
textView.setTextSize(18);
textView.setTextColor(Color.WHITE);
textView.setGravity(Gravity.CENTER);
textView.setPadding(0, 0, 0, 600);
textView.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
if (dialog.isShowing())
dialog.dismiss();
}
});
LayoutParams layoutParams = new LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT);
dialog.addContentView(textView, layoutParams);
dialog.show();
WindowManager windowManager = getActivity().getWindowManager();
Display display = windowManager.getDefaultDisplay();
WindowManager.LayoutParams lp = dialog.getWindow().getAttributes();
lp.width = (int) (display.getWidth()); // 设置宽度
lp.height = (int) (display.getHeight());
dialog.getWindow().setAttributes(lp);
// dialog.getWindow().setGravity(80);
}

styles.xml里面的代码：

<style name="custom_dialog" parent="android:style/Theme.Dialog">
<item name="android:background">#00000000</item>
<item name="android:windowBackground">@android:color/transparent</item>
<item name="android:windowNoTitle">true</item>
<item name="android:windowIsFloating">true</item>
</style>