In fact, this is caused by the project not being compiled by zend studio for eclipse (it should be indexed), so just let it recompile the project code.
The operation is as follows:
Create a new project at will, such as test. Then find the directory where the test project is located, copy both .cache and .setting in the directory to the directory of the project to be recompiled, and change the name in .project in the test project to the project name of the project to be recompiled. Then copy it to this directory and replace the original .project. Restart and wait for the compilation to complete to solve the code prompt problem.