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有两种出错的方式
1)布局文件ie xml文件的问题
2)如果你更新adt，那么就会出现R问题。 -你必须检查项目的属性 - goto->属性->Java构建路径->命令和导出，并检查所有的lib。
这将解决问题。
其他回答
您可能需要更新SDK工具。重新启动Android SDK管理器，并安装一个新项目:Android SDK Build-tools。
我尝试了上面的大多数方法，但对我的情况不起作用
最后我发现adb输了
对于MAC OS，进入android SDK目录
输入。/adb start-server
我也有这个问题。结果发现我无意中从strings.xml文件中删除了“app_name”字符串资源，这导致了一个无声错误。一旦我重新添加了它，R类就成功生成了，一切都恢复并运行了。
每次我遇到R未生成甚至消失的问题时，这都是由于XML布局文件中的某些问题导致应用程序无法构建。
R是一个生成的类。如果你正在使用Android开发工具(ADT)，它会在项目构建时生成。您可能已经关闭了“自动构建”。
So I have run into this problem multiple times when switching build targets. Usually doing a Project >> Clean worked for me. This last time, however, it did not. Finally I tried to open my default.properties file, located under the root project folder. I received an error message stating that it was out of sync with the file system. I actually deleted it and copied a coworkers version which allowed eclipse to rebuild my R file. I will paste what it looks like below. It is named 'default.properties'.
# This file is automatically generated by Android Tools.
# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
#
# This file must be checked in Version Control Systems.
#
# To customize properties used by the Ant build system use,
# "build.properties", and override values to adapt the script to your
# project structure.
# Indicates whether an apk should be generated for each density.
split.density=false
# Project target.
target=android-3
