Make alert dialog background transparent

问题

I am creating an alert dialog on Android Jelly Beans OS. Everything works well but what I want is that instead of the black background of the alert dialog I want a transparent background. I read so many articles and user's question on stackoverflow but none of them is helping me out.

Here is my code:

AlertDialog.Builder builder =  new AlertDialog.Builder(this, R.style.CustomAlertDialog);
    builder.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog1, int which) {
            gActivityResult = REQUEST_PICK_CONTACT;
            onResume();
            return;
        } }); 
    builder.setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog1, int which) {
            return;
        } }); 
    View view = getLayoutInflater().inflate(R.layout.alert_dialog, null);
    builder.setTitle(R.string.gender_age);
    builder.setInverseBackgroundForced(false);
    builder.setView (view);


    dialog = builder.create ();

Here is my CustomAlertDialog which is defined in res/values/styles.xml

<style name="CustomAlertDialog" parent="@android:style/Theme.Dialog">
    <!-- All customizations that are NOT specific to a particular API-level can go here. -->
    <item name="android:windowFrame">@null</item>
    <item name="android:windowIsFloating">true</item> 
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:windowAnimationStyle">@android:style/Animation.Dialog</item>
    <item name="android:windowBackground">@color/transparent_color</item>
    <item name="android:windowSoftInputMode">stateUnspecified|adjustPan</item>
    <item name="android:colorBackgroundCacheHint">@null</item>
    <item name="android:gravity">left</item>
</style>

Here is the color.xml

<resources>
   <color name="transparent_color">#00000000</color>
</resources>

But it didn't help me.

My question: Is this doable? If yes, can you please guide me in the right direction?

回答1:

If you haven't read Style attributes of custom styled AlertDialog question, you should go ahead and read. The answer suggests to use Dialog instead of Alert Dialog. Moreover reading Why does LayoutInflater ignore the layout_width and layout_height layout parameters I've specified? issue with LayoutInflater might clear a bit more. Hope it helps. Try it and let me know if it works.

回答2:

I found this way that is compatible with AlertDialog.Builder . Using the "Dump View Hierarchy" button in the Android "Devices" tab in Eclipse, I saw many nested FrameLayouts and it seemed like the background was in these, vs the window.

Traversing these Views and setting background to transparent on each actually worked (my custom view then floats over the dimmed app, with no frames or backgrounds, and there is no change in layout). I had a custom view, so traversed down from it, but traversing ViewGroups up from the Window should also work.

I am using an AlertDialog.Builder in my own DialogFragment subclass with a custom view.

   @Override
   public Dialog onCreateDialog(Bundle savedInstanceState) {
    final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    configureDialogBuilder(builder);

    final LayoutInflater inflater = getActivity().getLayoutInflater();
    customView = inflater.inflate(customViewId, null);
    builder.setView(customView);

    final AlertDialog dialog = builder.create();
    return dialog;
  }

  @Override
  public void onStart() {
    super.onStart();
    clearBackgrounds(customView);
  }

  private void clearBackgrounds(View view) {
    while (view != null) {
      view.setBackgroundResource(android.graphics.Color.TRANSPARENT);

      final ViewParent parent = view.getParent();
      if (parent instanceof View) {
        view = (View) parent;
      } else {
        view = null;
      }
    }
  }

回答3:

I had to do something similar for one of my projects. What I did was to create an Activity just for the AlertDialog.

Not sure if this is what you are after but posting it here in case it helps you...

Activity

public class ShowAlertDialogActivity extends FragmentActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.alert_dialog);

        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        // create the builder

        AlertDialog alert = builder.create();
        alert.show();
    }
}

And I set the background to transparent in the layout (alert_dialog.xml)...

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" 
    android:background="@android:color/transparent">
</LinearLayout>

And added the activity to the Manifest...

<activity
    android:name=".ShowAlertDialogActivity"
    android:label="@string/app_title"
    android:theme="@style/AppTheme"
    android:launchMode="singleTask" />

This did the job for me.

Hope this helps.

回答4:

simply call,

customDialog.getWindow().setBackgroundDrawable(new ColorDrawable(android.graphics.Color.TRANSPARENT));

just before

customDialog.show();

来源：https://stackoverflow.com/questions/17202452/make-alert-dialog-background-transparent