android - 如何在 xml 中将我们自己的背景图片设置为 facebook 登录按钮？

Question

是否可以在 xml 中为 Facebook 登录按钮设置我们自己的背景图片？

我的项目中的 xmlc(即 FBDemo)

<com.facebook.widget.LoginButton
    xmlns:facebook="http://schemas.android.com/apk/res-auto"
    android:id="@+id/btn_facebook"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_above="@+id/btn_login"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="15dp"
    facebook:background_image="@drawable/login_with_fb"
    facebook:confirm_logout="false"
    facebook:fetch_user_info="true" />

我在 Facebook SDK 中进行了这样的更改

在 FacebookSDK 项目中值/attr.xml

<declare-styleable name="com_facebook_login_view">
    <attr name="confirm_logout" format="boolean"/>
    <attr name="fetch_user_info" format="boolean"/>
    <attr name="login_text" format="string"/>
    <attr name="logout_text" format="string"/>
    <attr name="background_image" format="integer"/>
</declare-styleable>

在 LoginButton.java 中

private int background_image;
private void parseAttributes(AttributeSet attrs) {
    TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.com_facebook_login_view);
    confirmLogout = a.getBoolean(R.styleable.com_facebook_login_view_confirm_logout, true);
    fetchUserInfo = a.getBoolean(R.styleable.com_facebook_login_view_fetch_user_info, true);
    loginText = a.getString(R.styleable.com_facebook_login_view_login_text);
    logoutText = a.getString(R.styleable.com_facebook_login_view_logout_text);
    background_image = a.getInt(R.styleable.com_facebook_login_view_background_image, R.drawable.com_facebook_button_blue);

    a.recycle();
}

public LoginButton(Context context, AttributeSet attrs) {
    super(context, attrs);

    if (attrs.getStyleAttribute() == 0) {
        // apparently there's no method of setting a default style in xml,
        // so in case the users do not explicitly specify a style, we need
        // to use sensible defaults.
        this.setGravity(Gravity.CENTER);
        this.setTextColor(getResources().getColor(R.color.com_facebook_loginview_text_color));
        this.setTextSize(TypedValue.COMPLEX_UNIT_PX,
                getResources().getDimension(R.dimen.com_facebook_loginview_text_size));
        this.setTypeface(Typeface.DEFAULT_BOLD);
        if (isInEditMode()) {
            // cannot use a drawable in edit mode, so setting the background color instead
            // of a background resource.
            this.setBackgroundColor(getResources().getColor(R.color.com_facebook_blue));
            // hardcoding in edit mode as getResources().getString() doesn't seem to work in IntelliJ
            loginText = "Log in with Facebook";
        } else {
            //this.setBackgroundResource(R.drawable.com_facebook_button_blue);
            this.setBackgroundResource(background_image);
            this.setCompoundDrawablesWithIntrinsicBounds(R.drawable.com_facebook_inverse_icon, 0, 0, 0);
            this.setCompoundDrawablePadding(
                    getResources().getDimensionPixelSize(R.dimen.com_facebook_loginview_compound_drawable_padding));
            this.setPadding(getResources().getDimensionPixelSize(R.dimen.com_facebook_loginview_padding_left),
                    getResources().getDimensionPixelSize(R.dimen.com_facebook_loginview_padding_top),
                    getResources().getDimensionPixelSize(R.dimen.com_facebook_loginview_padding_right),
                    getResources().getDimensionPixelSize(R.dimen.com_facebook_loginview_padding_bottom));
        }
    }
    parseAttributes(attrs);
    if (!isInEditMode()) {
        initializeActiveSessionWithCachedToken(context);
    }        
}

我正在将我自己的背景传递到我的 xml 中的 Facebbok 登录按钮的 xml

但这给了我如下所示的运行时错误

08-07 06:41:59.492: E/AndroidRuntime(1731): Caused by: java.lang.NumberFormatException: Invalid int: "res/drawable-hdpi/login_with_fb.png"

我认为发生此错误是因为 login_with_fb.png 图像驻留在 FBDemo 中，而 FacebookSDK 项目在其中找不到可绘制图像 login_with_fb.png

我知道另一种方式，只是在 Activity 中设置背景图像，但我想在 xml 中设置有什么解决办法吗？？

Answer 1

请在您的 Facebook SDK 中更改以下代码:转到 com.facebook.widget.LoginButton.java

 public LoginButton(Context context, AttributeSet attrs) {
    super(context, attrs);

    if (attrs.getStyleAttribute() == 0) {
        // apparently there's no method of setting a default style in xml,
        // so in case the users do not explicitly specify a style, we need
        // to use sensible defaults.
        this.setGravity(Gravity.CENTER);
        this.setTextColor(getResources().getColor(R.color.com_facebook_loginview_text_color));
        this.setTextSize(TypedValue.COMPLEX_UNIT_PX,
                getResources().getDimension(R.dimen.com_facebook_loginview_text_size));
        this.setTypeface(Typeface.DEFAULT_BOLD);
        if (isInEditMode()) {
            // cannot use a drawable in edit mode, so setting the background color instead
            // of a background resource.
//                      this.setBackgroundColor(getResources().getColor(R.color.com_facebook_blue));
            // hardcoding in edit mode as getResources().getString() doesn't seem to work in IntelliJ
            loginText = "Log in with Facebook";
        } else {/*
            this.setBackgroundResource(R.drawable.com_facebook_button_blue);
            this.setCompoundDrawablesWithIntrinsicBounds(R.drawable.com_facebook_inverse_icon, 0, 0, 0);
            this.setCompoundDrawablePadding(
                    getResources().getDimensionPixelSize(R.dimen.com_facebook_loginview_compound_drawable_padding));
            this.setPadding(getResources().getDimensionPixelSize(R.dimen.com_facebook_loginview_padding_left),
                    getResources().getDimensionPixelSize(R.dimen.com_facebook_loginview_padding_top),
                    getResources().getDimensionPixelSize(R.dimen.com_facebook_loginview_padding_right),
                    getResources().getDimensionPixelSize(R.dimen.com_facebook_loginview_padding_bottom));
        */}
    }
    parseAttributes(attrs);
    if (!isInEditMode()) {
        initializeActiveSessionWithCachedToken(context);
    }        
}

同时从此方法中删除代码:

 private void setButtonText() {/*
    if (sessionTracker != null && sessionTracker.getOpenSession() != null) {
        setText((logoutText != null) ? logoutText :
                getResources().getString(R.string.com_facebook_loginview_log_out_button));
    } else {
        setText((loginText != null) ? loginText :
                getResources().getString(R.string.com_facebook_loginview_log_in_button));
    }
*/}

也可以在该方法的下方注释:

private void parseAttributes(AttributeSet attrs) {
    TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.com_facebook_login_view);
    confirmLogout = a.getBoolean(R.styleable.com_facebook_login_view_confirm_logout, true);
    fetchUserInfo = a.getBoolean(R.styleable.com_facebook_login_view_fetch_user_info, true);
  /*  loginText = a.getString(R.styleable.com_facebook_login_view_login_text);
    logoutText = a.getString(R.styleable.com_facebook_login_view_logout_text);*/
    a.recycle();
}

最后在下面的代码中粘贴您的主要 Activity 代码:

 loginButton = (LoginButton) findViewById(R.id.btn_facebook);
    loginButton.setReadPermissions(Arrays.asList("email","public_profile"));
    loginButton.setUserInfoChangedCallback(new LoginButton.UserInfoChangedCallback() {
        @Override
        public void onUserInfoFetched(GraphUser user) {
            WelcomeActivity.this.user = user;
            updateUI();
        }
    });

    loginButton.setBackgroundResource(R.drawable.btn_splash_fb);