R无法解决- Android错误

我刚刚下载并安装了新的Android SDK。我想创建一个简单的应用程序来测试它。

向导创建了以下代码:

package eu.mauriziopz.gps;

import android.app.Activity;
import android.os.Bundle;

public class ggps extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}

但是Eclipse给出了错误

R不能被分解

在网上

setContentView(R.layout.main);

Why?

PS:我在res/layout/下有一个名为main.xml的XML文件。

当前回答

R.java是Android Eclipse插件创建的文件构建应用程序。R.java是在“gen”下创建的目录中。此文件由“res”中的信息生成。目录中。如果在Eclipse上运行select“Project”->“Clean… 菜单，它将删除，然后重新生成R.java文件。

“R不能被解决”的问题发生在你改变你的在AndroidManifest.xml文件中的包名。它使用安卓系统包名下创建子目录“gen”目录，其中它存储R.java文件。

Eclipse may have problems executing clean, because it is confused about where the R.java file is when you have changed the Android package name. You can either rename the subdirectory under gen to match your new package name, or you can change your package name back to the old name. Do the clean and then change the package name to the new name you want. This works best if you stop Eclipse from trying to build while you are changing the package name. Under the "Project" menu uncheck the option to "Build Automatically" and also when the "Clean..." dialog asks if it should "Start a build immediately" uncheck the box so it doesn't try to build while you are changing the package name. After you have changed the name you can turn "Build Automatically" back on again.

Note that if your AndroidManifest.xml file package name does not match your Java package name, Eclipse will end up automatically adding an "import <your Android package name>.R;" line in all your .java files that have any references to R. If you change your AndroidManifest.xml package name, sometimes Eclipse does not update all of these added imports. If that happens, use the Eclipse refactoring (ALT + Shift + R) to change the import statement in one of your Java files to your new AndroidManifest.xml package name. It is best to do this while you have disabled "Build Automatically".

2010-03-04 18:37:14

其他回答

首先查看你的生成文件，看它是否包含你的包名和R.java。如果它是空的，可能你没有权限创建新文件，所以退出eclipse，然后右键单击，以管理员身份运行，清理项目，一切都会正确。

否则你的XML文件中可能会有错误，或者检查其他答案。

2013-07-01 09:26:47

我有这个问题很多次，我发现有时“R不会解决”，因为:

一些坏的资源已经存在，例如:一个名为My image .png的图像或者在资源中出现一些错误，比如在xml文件中出现错误，或者在你的表单中定义资源时出现错误。

在这种情况下，你甚至不能将你自己的包R导入到你的项目中。所以去你的资源文件夹，搜索以上两点。

这是可行的

2014-02-25 09:29:53

我认为问题出在layout.xml文件或import语句中。

请确保您没有导入R.android。，而不是导入R.YOUR PACKAGE NAME..