我改变了我的一个项目的相关项目和感动我的文件之一有做实验。 我现在搬到回来，但该项目将无法运行。 它告诉我，我有一个错误，尽管我看不到一个，清洁工程并没有帮助。 然而，该项目有一个惊叹号旁边。这是什么意思？

I changed the dependent projects of one of my project and moved one of my files there as an experiment. I now moved it back but the project won't run. It tells me I have an error even though I can't see one and "Clean project" doesn't help. However, the project has an exclamation mark next to it. What does that mean?

推荐答案

检查错误窗口。 我的第一个想法是，没有生成目标设定。右键单击该项目，选择Android和确保创建目标进行检查。有时你需要取消选中它，选择不同的API，应用设置，然后再次选择最初选择的API。

Check Errors window. My first idea would be that no build target is set. Right click the Project, select Android and make sure that a Build Target is checked. Sometimes you need to uncheck it, select a different API, apply settings, and then again select the API that was originally selected.