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

I would say "R can not be resolved" is something too general and can be misleading at times. I also had the same problem many times ago even when I first create a new project (which mean I did not mess with the code yet). Most of the time I just need to update my sdk manager (as some people have mentioned). But in my recent case, I found out that the path to my project file is too long (something like this E:\R&D\ANDROID\ANDROID BASIC\Folder 1\ Folder 2\..... \Folder n\MyProject). The folder names also contain spaces character. I thought it could be the case and indeed it's true, when I created a new project in another folder with shortest path possible, and none of the folders' names containing space character, it worked as normal.

2013-11-30 14:53:26

其他回答

如果您使用的是Mac，请检查. ds_store是否已添加到/res目录中(终端命令行中的ls -al)。删除它并刷新/重建。

2010-10-23 11:25:55

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

我今天也遇到了同样的问题。我尝试使用sdk管理器执行所有sdk更新。完成并重新启动IDE后，问题已解决。

2013-06-04 13:44:01

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%%。

2011-09-08 20:40:17

在将一些图形放入可绘制文件夹后，我也遇到了同样的问题。有一些错误，当我试图清理，R.java文件不存在。