为什么我的eclipse新建安卓项目是出现这个？

点击菜单栏中的Project——>Clean....，再保存一下就可以了

Form formPreview = new Form();
public Leaf(string name) : base(name) { }
public override void Add(Component c)
{
Console.WriteLine("Cannot add to a leaf");
}
public override void Remove(Component c)
{
Console.WriteLine("Cannot remove to a leaf");
}
public override void Display(int depth)
{
Console.WriteLine(new string('-',depth)+name);
}
}

AndroidManifest.xml文件丢失了，怎么弄你应该知道