如何检测Facebook应用程序是否安装在iOS上?[副本]

BOOL isInstalled = [[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:@"fb://"]]

if (isInstalled) {

} else {

}

尝试仅使用 canOpenURL: 作用

NSURL *fbURL = [NSURL URLWithString:@"fb://"];//or whatever url you're checking

if ([[UIApplication sharedApplication] canOpenURL:fbURL])
{
  //open it etc  
}