My eclipse shows that my project is wrong, but there is no specific hint, what s going on? Confused?

In the Problems tab below Eclipse there is a record of all your errors and warnings, you can see the specific reason, the red cross means that there is an error, according to what you said, it is likely that the absolute path was used when importing the external jar package. Follow the prompts in the problems tab, go for it, and if there is, put those packages into the lib of the project and reload them.

Please refer to it.

Re-import the relevant jar package, and that's it.

The path of the compressed package is different from the original development.,It's estimated that you went down the Internet or was later moved by you.,And the path of the library you used didn't change it together.,It will become like this.。 For more information, you can see the "Questions" section under Eclipse.

jar import issue.

Take a look inside the build path.

window - show view - problems

Then look at what the problems interface says

Show the infamous red cross fork is estimated to be bulidpath not configured correctly!

It is recommended to check the buildpath of the project.

I'm having this problem too, how did you solve it?

There are a few main reasons why your project is missing:

1.Due to the problem of trying on and adjusting the window first, you only need to change the corresponding attempt under the window option in the menu bar, because the screenshot of the building book is somewhat general. So there's no way to tell you exactly what to change.

2.Your workspace has changed, i.e. the workplace selection has changed when the software was just launched, it's as simple as restarting the program and selecting the space where the project is located.

3.This situation is rare, that is, because of the illegal accidental closure of the project deployment file is lost, just re-import, find the file where your original project is located, drag and drop the entire folder or automatically import it.

There's a windows window on top of it, and there's a show in there that brings it up.

There are many scenarios for this, and each case involves different factors.

One of the most typical cases is when there are no errors in the project but Eclipse reports errors.

Eclipse analyzes the source code and its dependencies for the entire project asynchronously at the same time as the user's source code files, and asynchronously updates the results (some of which are the error messages mentioned by the subject) to the user interface.

Sometimes, these analyses may not properly trigger an update after the user, or only partially update the information without enough global information, resulting in an error redundancy reported by Eclipse.

In this case, doing a clean rebuild is forcing Eclipse to do a global update analysis, so that the previous false positives may disappear.

Another typical scenario is that there are errors in the project, but after a clean rebuild there are no errors for a while, only to start reporting errors after a while.

This is also related to the asynchronous analysis and update mentioned above.

When a complete clean rebuild is done, the Eclipse interface will clear all bug reports, but if there are any bugs in the project, they will still be reported to the interface after the analysis is complete.

Normal log output can be ignored if it does not affect the program operation.

The installation directory of git was not detected.

It doesn't matter if you don't want git.

2. After clicking OK, the above v7 error is solved, and now to solve the reason why the r file cannot be generated, most of the cases are the xml file error. Find it below:

3. Check the error points under res values.

V11 and V14 have the same modifications, and you can also delete them directly. After changing it, it's right.

4. Try it.

It's okay to look at you, and it's okay to run.

I see that you have a red dot here, so let's see what the error message is.

In addition, downstairs said that the interface does not declare public, the method of the interface is public by default, and there is no need to manually declare it.

Override is the canonical way to tell the compiler that the method is to override the parent class, but it's not necessary and won't cause you to make mistakes. Receiving dog with animal is also not the root cause. I suggest you break at line 20 to see if the dog object is using the dog you declared above.

animal dog = new dog();

In the dog class, you need to write @override

The implementation interface methods are exactly the same, one public, one not.