启用另一个程序某些方法

DexFile df = new DexFile(new File("/data/app/my_downloaded_lib.apk")); 
ClassLoader cl = getClassLoader(); 
Class clazz = df.loadClass("com/my/lib/MyClass", cl); 

2.cl = new DexClassLoader("/full/path/com.example.apk", 
                        getFilesDir().getAbsolutePath(),// /data/data/foo/files 
                        null,  // native lib path, I haven't used this 
                        MyClass.class.getClassLoader()); 
// This doesn't make Class.forName() work, instead I do this: 
Class<?> foo = cl.loadClass("com.example.foo"); 
3.

PathClassLoader( "/data/app/org.startsmall.myapp.apk" ,
                ClassLoader.getSystemClassLoader());

final String apkFiles =              "/data/app/org.startsmall.myapp.apk:" + // myself              // handlers defined by other developers              "/data/app/" + handlerClassName.substring( 0 , lastDotPos) + ".apk" ;             dalvik.system.PathClassLoader myClassLoader =              new dalvik.system.PathClassLoader(                  apkFiles,                  ClassLoader.getSystemClassLoader());              // ...             try {              Class<?> handler =                  Class.forName(handlerClassName, true , classLoader);                 // Call reflective APIs.            } catch (ClassNotFoundException e) {              // .....