Android Facebook分享对话

Question

我按照教程“https://developers.facebook.com/docs/android/share-dialog/#sharelink”中的每一步操作，但我无法进行shareDialog show。这是我的代码：

        if (FacebookDialog.canPresentShareDialog(getApplicationContext(), 
            FacebookDialog.ShareDialogFeature.SHARE_DIALOG)) {
        FacebookDialog shareDialog = new FacebookDialog.ShareDialogBuilder(Login.this)
        .setApplicationName(getString(R.string.app_name))
        .setName("Hello This is a Share")
        .setLink("www.gooogle.com")
        .build();

        //uiHelper.trackPendingDialogCall(shareDialog.present());   
        shareDialog.present();
    }

另外，manifest.xml很好。