Android Studio无法找到默认活动 [英] Android Studio cannot find default activity

问题描述

我已经挣扎了两天了。无论我做什么，在Windows 10 64上运行的Android Studio 2.1.1一直在抛出

I've struggled with this for two days now.No matter what I do, Android Studio 2.1.1 , running on windows 10 64 keeps throwing

无法识别启动活动：未找到默认活动
启动活动时出错。

Could not identify launch activity: Default Activity not found Error while Launching activity .

此外，语法突出显示对于java文件也不起作用，即我的MainActivity.java文件根本没有语法检查。

Also, syntax highlighting for java files isn't working either, i.e. my MainActivity.java file has no syntax checking at all.

我对任何SO答案都没有运气，主要包括以下一个或多个：

I've had no luck with any SO answers which mainly included one or more of the below:

我试过

1-使缓存无效并重新启动android studio

1- Invalidating caches and restarting android studio

2-清洁/重建

3-重启窗户

4-完全删除android studio并从头开始重新安装

4- Completely removing android studio and reinstalling from scratch

5- Gradle resync

5- Gradle resync

6-尝试创建具有不同SDK的新项目只是为了获得至少一个构建 - 没有吗

6- Trying to create new projects with varying SDKs just to get atleast one to build- none does

任何想法为什么会发生这种情况？作为参考，我的文件在

Any ideas why this is happening? For reference , my files are below

MainActivity.java:
package com.example.simpleapp.simpleapp;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

AndroidManifest.xml （.MainActivity是红色，它也找不到）

AndroidManifest.xml ( the .MainActivity is in red, it can't find that either)

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.simpleapp.simpleapp">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Gradle项目文件

Gradle Project File

 buildscript {
        repositories {
            jcenter()
        }
        dependencies {
            classpath 'com.android.tools.build:gradle:2.1.0'

            // NOTE: Do not place your application dependencies here; they belong
            // in the individual module build.gradle files
        }
    }

    allprojects {
        repositories {
            jcenter()
        }
    }

    task clean(type: Delete) {
        delete rootProject.buildDir
    }

Gradle模块文件

Gradle Module file

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.3"

    defaultConfig {
        applicationId "com.example.simpleapp.simpleapp"
        minSdkVersion 21
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.4.0'
}

谢谢

推荐答案

在经历了许多令人沮丧的时间之后，我发现以某种方式MainActivity.java被添加为可识别的文件类型。不知道怎么做，但是随着 Add-> New Activity 向导添加的所有活动的默认名称是MainActivity，android studio始终将MainActivity.java视为jsp。因此，每次添加新活动时，永远不会找到主要活动！

OK after many frustrating hours, I discovered that somehow "MainActivity.java" got added as a recognized file type. No idea how, but as the default name for all activities added with Add->New Activity wizard is "MainActivity", android studio always treated "MainActivity.java" as jsp. So every time I added a new activity , it could never find the main activity!

我转到文件 - >设置 - >编辑器 - >文件类型，并在识别的文件类型下的右侧窗格中删除了MainActivity.java。

I went to File -> Settings -> Editor -> FileTypes and removed "MainActivity.java" in the right hand pane under "Recognized File Types".

这解决了问题。希望它可以帮助别人。

This fixed the problem. Hope it helps someone else.

这篇关于Android Studio无法找到默认活动的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！