错误:无法解决方法

Question

我是最新的AndroidStudio2.1.1，我正在尝试制作一个简单的计算器。但我遇到了一个非常奇怪的问题，由于某些原因，有许多方法无法解决。为了确保我没有搞砸任何重要的文件，我复制了所有的代码并将其粘贴到一个新的项目中。但是我仍然有错误，也许我需要重新安装Android？我的项目是什么样子

这是我的留言：

Information:Gradle tasks [:app:assembleDebug]
:app:preBuild UP-TO-DATE
:app:preDebugBuild UP-TO-DATE
:app:checkDebugManifest
:app:prepareDebugDependencies
:app:compileDebugAidl UP-TO-DATE
:app:compileDebugRenderscript UP-TO-DATE
:app:generateDebugBuildConfig UP-TO-DATE
:app:mergeDebugShaders UP-TO-DATE
:app:compileDebugShaders UP-TO-DATE
:app:generateDebugAssets UP-TO-DATE
:app:mergeDebugAssets UP-TO-DATE
:app:generateDebugResValues UP-TO-DATE
:app:generateDebugResources UP-TO-DATE
:app:mergeDebugResources UP-TO-DATE
:app:processDebugManifest UP-TO-DATE
:app:processDebugResources UP-TO-DATE
:app:generateDebugSources UP-TO-DATE
:app:incrementalDebugJavaCompilationSafeguard UP-TO-DATE
:app:compileDebugJavaWithJavac
:app:compileDebugJavaWithJavac - is not incremental (e.g. outputs have changed, no previous execution, etc.).
C:\Users\Home\AndroidStudioProjects\CalcuterTest\app\src\main\java\com\kingjulian\www\calcutertest\MainActivity.java
:app:compileDebugJavaWithJavac FAILED
Error:Execution failed for task ':app:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.
Information:BUILD FAILED
Information:Total time: 1.612 secs
Information:30 errors
Information:0 warnings
Information:See complete output in console

我的分级控制台：

Executing tasks: [:app:assembleDebug]
Configuration on demand is an incubating feature.
Incremental java compilation is an incubating feature.
:app:preBuild UP-TO-DATE
:app:preDebugBuild UP-TO-DATE
:app:checkDebugManifest
:app:prepareDebugDependencies
:app:compileDebugAidl UP-TO-DATE
:app:compileDebugRenderscript UP-TO-DATE
:app:generateDebugBuildConfig UP-TO-DATE
:app:mergeDebugShaders UP-TO-DATE
:app:compileDebugShaders UP-TO-DATE
:app:generateDebugAssets UP-TO-DATE
:app:mergeDebugAssets UP-TO-DATE
:app:generateDebugResValues UP-TO-DATE
:app:generateDebugResources UP-TO-DATE
:app:mergeDebugResources UP-TO-DATE
:app:processDebugManifest UP-TO-DATE
:app:processDebugResources UP-TO-DATE
:app:generateDebugSources UP-TO-DATE
:app:incrementalDebugJavaCompilationSafeguard UP-TO-DATE
:app:compileDebugJavaWithJavac
:app:compileDebugJavaWithJavac - is not incremental (e.g. outputs have changed, no previous execution, etc.).

C:\Users\Home\AndroidStudioProjects\CalcuterTest\app\src\main\java\com\kingjulian\www\calcutertest\MainActivity.java:26: error: cannot find symbol
        super.onCreate(savedInstanceState);
             ^
  symbol: method onCreate(Bundle)
C:\Users\Home\AndroidStudioProjects\CalcuterTest\app\src\main\java\com\kingjulian\www\calcutertest\MainActivity.java:27: error: cannot find symbol
        setContentView(R.layout.activity_main);
        ^
  symbol:   method setContentView(int)
  location: class MainActivity
C:\Users\Home\AndroidStudioProjects\CalcuterTest\app\src\main\java\com\kingjulian\www\calcutertest\MainActivity.java:24: error: method does not override or implement a method from a supertype
    @Override
    ^
C:\Users\Home\AndroidStudioProjects\CalcuterTest\app\src\main\java\com\kingjulian\www\calcutertest\MainActivity.java:32: error: cannot find symbol
        one = (Button) findViewById(R.id.one);
                       ^
  symbol:   method findViewById(int)
  location: class MainActivity
C:\Users\Home\AndroidStudioProjects\CalcuterTest\app\src\main\java\com\kingjulian\www\calcutertest\MainActivity.java:33: error: cannot find symbol
        two = (Button) findViewById(R.id.two);
                       ^

                           ^
  symbol:   method findViewById(int)
  location: class MainActivity
C:\Users\Home\AndroidStudioProjects\CalcuterTest\app\src\main\java\com\kingjulian\www\calcutertest\MainActivity.java:51: error: cannot find symbol
        answer = (TextView) findViewById(R.id.answer);
                            ^
  symbol:   method findViewById(int)
  location: class MainActivity
23 errors

:app:compileDebugJavaWithJavac FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 1.411 secs

Answer 1

我现在能画的唯一一件事是怀疑您的类extends Activity，因为其中一些调用不能被“解析”，并且可能意味着它们不知道它们应该来自context.findViewById()。此外，@Override上也有一个错误行，因此它可能会认为您不需要创建覆盖。确保您还可以使用import android.app.Activity (这看起来像一个活动，因为它调用的是onCreate()而不是onCreateView()，后者是片段)。还有android.os.Bundle。