自定义Facebook按钮图像未居中

我已经创建了一个自定义的Facebook登录按钮。一切正常，但我无法在按钮中使图像居中（上/下）。它本身就是图像，但当我创建此按钮时，图像较低

//FB Button (Uses Facebook SDK)
self.fbLoginButton = [[FBLoginView alloc] init];
for (id loginObject in self.fbLoginButton.subviews)
{
    if ([loginObject isKindOfClass:[UIButton class]])
    {
        UIButton * loginButton =  loginObject;
        UIImage *loginImage = [UIImage imageNamed:@"Facebook_White.png"];
        [loginButton setBackgroundImage:loginImage forState:UIControlStateNormal];
        [loginButton setBackgroundImage:nil forState:UIControlStateSelected];
        [loginButton setBackgroundImage:nil forState:UIControlStateHighlighted];
        [loginButton setTitle:nil forState:UIControlStateNormal];
        [loginButton setTitle:nil forState:UIControlStateSelected];
        [loginButton setTitle:nil forState:UIControlStateHighlighted];

    }
    if ([loginObject isKindOfClass:[UILabel class]])
    {
        UILabel * loginLabel =  loginObject;
        loginLabel.text = @"";
        loginLabel.frame = CGRectMake(0, 0, 0, 0);
    }
}
self.fbLoginButton.delegate = self;
self.fbLoginButton.readPermissions = @[@"public_profile", @"email"];

[[self.fbLoginButton layer]setBorderWidth:2.0];
[[self.fbLoginButton layer]setBorderColor:UIColorFromRGB(0xbbffd6).CGColor];

[buttonsArray addObject:self.fbLoginButton];

以下是它与Twitter按钮相比的外观：

以下是实际的.png（文本为白色，因此除非背景为：

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有什么建议吗？

玩过之后，这对我来说很有效。我不得不硬编码fbLoginView.frame和loginButton.frame

//FB Button (Uses Facebook SDK)
self.fbLoginView = [[FBLoginView alloc] init];
self.fbLoginView.readPermissions = @[@"public_profile", @"email"];
self.fbLoginView.frame = CGRectMake(0, 0, 35, 35);
[[self.fbLoginView layer]setBorderWidth:2.0];
[[self.fbLoginView layer]setBorderColor:UIColorFromRGB(0xbbffd6).CGColor];

for (id loginObject in self.fbLoginView.subviews)
{
    if ([loginObject isKindOfClass:[UIButton class]])
    {
        UIButton * loginButton =  loginObject;
        loginButton.frame = CGRectMake(self.fbLoginView.frame.origin.x, self.fbLoginView.frame.origin.y, 35, 35);
        UIImage *loginImage = [UIImage imageNamed:@"Facebook_White.png"];
        [loginButton setBackgroundImage:loginImage forState:UIControlStateNormal];
        [loginButton setBackgroundImage:nil forState:UIControlStateSelected];
        [loginButton setBackgroundImage:nil forState:UIControlStateHighlighted];
    }
    if ([loginObject isKindOfClass:[UILabel class]])
    {
        UILabel * loginLabel =  loginObject;
        loginLabel.text = @"";
        loginLabel.frame = CGRectMake(0, 0, 0, 0);
    }
}

self.fbLoginView.delegate = self;
[socialButtonsArray addObject:self.fbLoginView];

---

我不会使用自定义Facebook按钮，但如果看不到你的

Facebook\u-White.png

的屏幕截图/图像，我就不知道如何修复它。已使用屏幕更新。很抱歉，我整周都不在城里：(