AlertDialog: How To Remove Black Borders Above and Below View

问题

This question has been asked before: AlertDialog custom title has black border

But was not answered satisfactorily - and is missing some information.

---

I'm trying to create a custom dialog in Android without a title and without any buttons along the bottom.

However, the resulting dialog has black "borders"/"spacing"/something along the top and bottom of the view.

From the Documentation:

A dialog made with the base Dialog class must have a title. If you don't call setTitle(), then the space used for the title remains empty, but still visible. If you don't want a title at all, then you should create your custom dialog using the AlertDialog class. However, because an AlertDialog is created easiest with the AlertDialog.Builder class, you do not have access to the setContentView(int) method used above. Instead, you must use setView(View). This method accepts a View object, so you need to inflate the layout's root View object from XML.

So, that's what I did:

Welcome.java

public class Welcome  extends Activity
{
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.welcome);

        LayoutInflater inflater = (LayoutInflater)this.getSystemService(LAYOUT_INFLATER_SERVICE);
        View layout = inflater.inflate(R.layout.welcomedialog, (ViewGroup)findViewById(R.id.layout_root));

        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setView(layout);
        builder.create().show();
    }
}

welcomedialog.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:background="@drawable/texturebg"
              android:id="@+id/layout_root"
              android:orientation="vertical"
              android:padding="40px">
    ...
</LinearLayout>

NOTE: I've tried using FrameLayout as the root ViewGroup instead of LinearLayout as per a suggestion I found somewhere - but that didn't help.

Result

---

setBackgroundDrawable Suggestion

public class Welcome  extends Activity
{
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.welcome);

        LayoutInflater inflater = (LayoutInflater)this.getSystemService(LAYOUT_INFLATER_SERVICE);
        View layout = inflater.inflate(R.layout.welcomedialog, (ViewGroup)findViewById(R.id.layout_root));

        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setView(layout);
        AlertDialog dialog = builder.create();

        dialog.getWindow().setBackgroundDrawable(new ColorDrawable(0));

        dialog.show();
    }
}

Didn't work for me.

回答1:

If you look at the AlertDialog class source you'll see most of the methods are simply proxy methods (facade) around private AlertController mAlert.

Looking at the AlertController class source you'll see 4 interesting member variables:

private int mViewSpacingLeft;
private int mViewSpacingTop;
private int mViewSpacingRight;
private int mViewSpacingBottom;
private boolean mViewSpacingSpecified = false;

Setting mViewSpacingSpecified to true will remove the borders on the top and bottom of the dialog.

This is done properly by changing this line:

dialog.setView(layout);

to:

dialog.setView(layout, 0, 0, 0, 0);

回答2:

dialog.setInverseBackgroundForced(true);

use the above in your code to remove the border of the alert dialog.

Refer this LINK for InverseBackgroundForced.

UPDATED Try this code::::

public class Welcome  extends Activity
{
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.welcome);

        AlertDialog.Builder builder = new AlertDialog.Builder(Welcome.this);
        LayoutInflater _inflater = LayoutInflater.from(Welcome.this);
        View view = _inflater.inflate(R.layout.welcomedialog,null);
        builder.setView(view);

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

Note:: Also try by removing android:padding="40px" from welcomedialog.xml.

回答3:

In my case, that border was caused by the theme of the parent Activity for the AlertDialog. To get rid of the border completely, give it a different theme (in this case, Holo):

AlertDialog.Builder builder = new AlertDialog.Builder(
                                new ContextThemeWrapper(this, android.R.style.Theme_Holo)
                              );

This fixed it for me. Hope this helps!

回答4:

Just to make Steve's answer more clear, this can be done easily. For example in my case the view I was setting in the dialog was a WebView.

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {

    WebView webView = new WebView(getActivity());
    webView.loadUrl(" url to show ");


    OnClickListener clickListenerOk = new OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            ...
        }
    };

    OnClickListener clickListenerCancel = new OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            ...
        }
    };

    AlertDialog dialog = new AlertDialog.Builder(getActivity())

            .setPositiveButton("OK", clickListenerOk)

            .setNegativeButton("Cancel",clickListenerCancel)

            .create();

    dialog.setView(webView, 0, 0, 0, 0);

    return dialog;
}

回答5:

setBackgroundDrawable(new ColorDrawable(0));

Call this in your dialog.

来源：https://stackoverflow.com/questions/10433764/alertdialog-how-to-remove-black-borders-above-and-below-view