AX7 Form继承接口

interface MyInterface
{
    public void setValue(str _val)
    {
    }

}

public class MyForm1 extends FormRun implements MyInterface
{
     void setValue(str _val)
     {
        FormControl1.text(_val);
     }
}    

public void setCallerField()
{
     MyInterface  callerFormRun;

     callerFormRun = element.args().caller() as MyInterface ;
     callerFormRun.setValue("test");
}