# Compiler Error CS0266 无法将类型“type1”隐式转换为“type2”。存在显式转换（是否缺少强制转换？） 当代码尝试在无法进行隐式转换的两个类型上尝试转换时，此错误发生。有关详细信息，请参阅[强制转换和类型转换（C# 编程指南）](https://msdn.microsoft.com/zh-cn/library/ms173105.aspx)。 下面的代码演示生成 CS0266 的示例。 ``` // CS0266.cs class MyClass { public static void Main() { // You cannot implicitly convert a double to an integer. double d = 3.2; // The following line causes compiler error CS0266. int i1 = d; // However, you can resolve the error by using an explicit conversion. int i2 = (int)d; // You cannot implicitly convert an object to a class type. object obj = "MyString"; // The following assignment statement causes error CS0266. MyClass myClass = obj; // You can resolve the error by using an explicit conversion. MyClass c = ( MyClass )obj; // You cannot implicitly convert a base class object to a derived class type. MyClass mc = new MyClass(); DerivedClass dc = new DerivedClass(); // The following line causes compiler error CS0266. dc = mc; // You can resolve the error by using an explicit conversion. dc = (DerivedClass)mc; } } class DerivedClass : MyClass { } ```