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

尝试使您的新XML布局文件名小写。例如,使用my_file.xml而不是myFile.xml。

其他回答

每次我遇到这个错误,总是落在SO。 说到底,原因都是一样的。

所以请永远记住这张小纸条

我发现大部分时间的原因是-错误的XML布局

如果您的XML不正确,则R文件不会在 构建。

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".

将构建目标从1.5或1.6更改为2.2 (API版本8),并检查string.xml中是否有%字符。如果是,则替换为%%。

检查XML文件名。确保它们都是小写的。

还要确保所有图像资源名称也都是小写的。我在我的jpg文件的名称中有一个大写字母,这在我的项目中导致了R未解决的错误。

确定你是否在寻找R.drawable。*该文件存在于可绘制的*文件夹中。