Java Android应用无法启动活动组件信息

我是android编程新手，最近，我的很多应用程序都出现了这个错误

以下是运行时堆栈跟踪：

01/26 17:02:17: Launching WelcomeActivity
$ adb shell am start -n "com.example.android.smartswitch/com.example.android.smartswitch.WelcomeActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Client not ready yet..Connected to process 4258 on device genymotion-custom_phone___7_0_0___api_24___768x1280-192.168.160.101:5555
W/System: ClassLoader referenced unknown path: /data/app/com.example.android.smartswitch-2/lib/x86
I/InstantRun: Instant Run Runtime started. Android package is com.example.android.smartswitch, real application class is null.
W/System: ClassLoader referenced unknown path: /data/app/com.example.android.smartswitch-2/lib/x86
W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.example.android.smartswitch, PID: 4258
              java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.android.smartswitch/com.example.android.smartswitch.WelcomeActivity}: java.lang.IllegalStateException: Already attached
                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
                  at android.app.ActivityThread.-wrap12(ActivityThread.java)
                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
                  at android.os.Handler.dispatchMessage(Handler.java:102)
                  at android.os.Looper.loop(Looper.java:154)
                  at android.app.ActivityThread.main(ActivityThread.java:6077)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
               Caused by: java.lang.IllegalStateException: Already attached
                  at android.support.v4.app.FragmentManagerImpl.attachController(FragmentManager.java:2815)
                  at android.support.v4.app.FragmentController.attachHost(FragmentController.java:104)
                  at android.support.v4.app.FragmentActivity.onCreate(FragmentActivity.java:317)
                  at android.support.v7.app.AppCompatActivity.onCreate(AppCompatActivity.java:88)
                  at com.example.android.smartswitch.WelcomeActivity.onCreate(WelcomeActivity.java:36)
                  at android.app.Activity.performCreate(Activity.java:6664)
                  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599)
                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) 
                  at android.app.ActivityThread.-wrap12(ActivityThread.java) 
                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) 
                  at android.os.Handler.dispatchMessage(Handler.java:102) 
                  at android.os.Looper.loop(Looper.java:154) 
                  at android.app.ActivityThread.main(ActivityThread.java:6077) 
                  at java.lang.reflect.Method.invoke(Native Method) 
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) 
Application terminated.

我正在尝试制作一个android应用程序，它有一个类似的内置滑块。这是MainActivity.java文件：

package com.example.android.smartswitch;

import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {

int controllerButton = 1;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    // but this is for testing
    slidingScreenLauncher prefManager = new slidingScreenLauncher(getApplicationContext());
    prefManager.setFirstTimeLaunch(true);


    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.addDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);
}

public void onButtonClick (View view) {
    String message = null;
    switch (view.getId())  {
        case R.id.settingsButton:
            Intent intent = new Intent(this, logging_screen.class);
            startActivity(intent);
            break;

        case R.id.controllerButton:
            if (controllerButton == 1)  {
                Button button1 = (Button) findViewById(R.id.controllerButton);
                button1.setBackgroundColor(Color.GREEN);        //Changing the background of the controllerButton.
                button1.setText(getString(R.string.controller_off_text));
                Button headerButton = (Button) findViewById(R.id.headerText);
                headerButton.setBackgroundColor(Color.RED);
                headerButton.setTextColor(Color.BLACK);
                headerButton.setText(getString(R.string.banner_off_text));

                controllerButton--;         //Setting the button int to zero for next change.
            }

            if (controllerButton == 0)  {
                Button button1 = (Button) findViewById(R.id.controllerButton);
                button1.setBackgroundColor(Color.BLUE);        //Changing the background of the controllerButton.
                button1.setText(getString(R.string.controller_on_text));
                Button headerButton = (Button) findViewById(R.id.headerText);
                headerButton.setBackgroundColor(Color.BLACK);
                headerButton.setTextColor(Color.WHITE);
                headerButton.setText(getString(R.string.banner_on_text));
                controllerButton++;         //Setting the button int to one for nex change. An altering loop.
            }
            break;
    }
}


@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();

    if (id == R.id.scheduleSettingsSideBar) {
        //Intent to send the user to scheduleSettings Screen.
        Intent intent = new Intent(this, WelcomeActivity.class);
        startActivity(intent);

    } else if (id == R.id.manualSettingsSideBar) {

    } else if (id == R.id.tempSettingsSideBar) {
        //Intent to send the user to tempSettings Screen.
        Intent intent = new Intent(this, temp_screen.class);
        startActivity(intent);
    }

    else if (id == R.id.randomDelaySideBar) {
        Intent intent = new Intent(this, random_delay.class);
        startActivity(intent);

    } else if (id == R.id.humiditySettingsSideBar) {
        Intent intent = new Intent(this, humidity_settings.class);
        startActivity(intent);

    } else if (id == R.id.loggingSideBar) {
        //Intent to send the user to loggingSidebar.
        Intent intent = new Intent(this, logging_screen.class);
        startActivity(intent);

    } else if (id ==R.id.generalSettingsSideBar) {

    } else if (id == R.id.playSliderAgain) {
        /* We normally won't show the welcome slider again in real app
        // but this is for testing
        slidingScreenLauncher prefManager = new slidingScreenLauncher(getApplicationContext());
        // make first time launch TRUE
        prefManager.setFirstTimeLaunch(true);
        startActivity(new Intent(MainActivity.this, WelcomeActivity.class));
        finish(); */
    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
  }
}

以下是WelcomActivity.java文件，该文件应显示导入滑块：

package com.example.android.smartswitch;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.os.Build;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.text.Html;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

public class WelcomeActivity extends AppCompatActivity {

private ViewPager viewPager;
private MyViewPagerAdapter myViewPagerAdapter;
private LinearLayout dotsLayout;
private TextView[] dots;
private int[] layouts;
private Button btnSkip, btnNext;
private slidingScreenLauncher prefManager;

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

    super.onCreate(savedInstanceState);

    // Checking for first time launch - before calling setContentView()
    prefManager = new slidingScreenLauncher(this);
    if (!prefManager.isFirstTimeLaunch()) {
        launchHomeScreen();
        finish();
    }

    // Making notification bar transparent
    if (Build.VERSION.SDK_INT >= 21) {
        getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
    }

    setContentView(R.layout.activity_welcome);

    viewPager = (ViewPager) findViewById(R.id.view_pager);
    dotsLayout = (LinearLayout) findViewById(R.id.layoutDots);
    btnSkip = (Button) findViewById(R.id.btn_skip);
    btnNext = (Button) findViewById(R.id.btn_next);


    // layouts of all welcome sliders
    // add few more layouts if you want
    layouts = new int[]{
            R.layout.welcome_slide1,
            R.layout.welcome_slide2,
            R.layout.welcome_slide3,
            R.layout.welcome_slide4};

    // adding bottom dots
    addBottomDots(0);

    // making notification bar transparent
    changeStatusBarColor();

    myViewPagerAdapter = new MyViewPagerAdapter();
    viewPager.setAdapter(myViewPagerAdapter);
    viewPager.addOnPageChangeListener(viewPagerPageChangeListener);

    btnSkip.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            launchHomeScreen();
        }
    });

    btnNext.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // checking for last page
            // if last page home screen will be launched
            int current = getItem(+1);
            if (current < layouts.length) {
                // move to next screen
                viewPager.setCurrentItem(current);
            } else {
                launchHomeScreen();
            }
        }
    });
}

private void addBottomDots(int currentPage) {
    dots = new TextView[layouts.length];

    int[] colorsActive = getResources().getIntArray(R.array.array_dot_active);
    int[] colorsInactive = getResources().getIntArray(R.array.array_dot_inactive);

    dotsLayout.removeAllViews();
    for (int i = 0; i < dots.length; i++) {
        dots[i] = new TextView(this);
        dots[i].setText(Html.fromHtml("&#8226;"));
        dots[i].setTextSize(35);
        dots[i].setTextColor(colorsInactive[currentPage]);
        dotsLayout.addView(dots[i]);
    }

    if (dots.length > 0)
        dots[currentPage].setTextColor(colorsActive[currentPage]);
}

private int getItem(int i) {
    return viewPager.getCurrentItem() + i;
}

private void launchHomeScreen() {
    prefManager.setFirstTimeLaunch(false);
    startActivity(new Intent(WelcomeActivity.this, MainActivity.class));
    finish();
}

//  viewpager change listener
ViewPager.OnPageChangeListener viewPagerPageChangeListener = new ViewPager.OnPageChangeListener() {

    @Override
    public void onPageSelected(int position) {
        addBottomDots(position);

        // changing the next button text 'NEXT' / 'GOT IT'
        if (position == layouts.length - 1) {
            // last page. make button text to GOT IT
            btnNext.setText(getString(R.string.start));
            btnSkip.setVisibility(View.GONE);
        } else {
            // still pages are left
            btnNext.setText(getString(R.string.next));
            btnSkip.setVisibility(View.VISIBLE);
        }
    }

    @Override
    public void onPageScrolled(int arg0, float arg1, int arg2) {

    }

    @Override
    public void onPageScrollStateChanged(int arg0) {

    }
};

/**
 * Making notification bar transparent
 */
private void changeStatusBarColor() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        Window window = getWindow();
        window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
        window.setStatusBarColor(Color.TRANSPARENT);
    }
}

/**
 * View pager adapter
 */
public class MyViewPagerAdapter extends PagerAdapter {
    private LayoutInflater layoutInflater;

    public MyViewPagerAdapter() {
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        View view = layoutInflater.inflate(layouts[position], container, false);
        container.addView(view);

        return view;
    }

    @Override
    public int getCount() {
        return layouts.length;
    }

    @Override
    public boolean isViewFromObject(View view, Object obj) {
        return view == obj;
    }


    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        View view = (View) object;
        container.removeView(view);
    }
  }
}

package com.example.android.smartswitch；
导入android.support.v7.app.AppActivity；
导入android.os.Bundle；
导入android.content.Context；
导入android.content.Intent；
导入android.graphics.Color；
导入android.os.Build；
导入android.support.v4.view.PagerAdapter；
导入android.support.v4.view.ViewPager；
导入android.text.Html；
导入android.view.LayoutInflater；
导入android.view.view；
导入android.view.ViewGroup；
导入android.view.Window；
导入android.view.WindowManager；
导入android.widget.Button；
导入android.widget.LinearLayout；
导入android.widget.TextView；
公共类WelcomeActivity扩展了AppCompatActivity{
私人视页机视页机；
私人MyViewPagerAdapter MyViewPagerAdapter；
私人线路布局点slayout；
私有文本视图[]点；
私人int[]布局；
专用按钮btnSkip，btnNext；
私人幻灯片放映管理器；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_welcome）；
super.onCreate（savedInstanceState）；
//正在检查首次启动-在调用setContentView（）之前
prefManager=新的滑动屏幕启动器（此）；
如果（！prefManager.isFirstTimeLaunch（））{
启动主屏幕（）；
完成（）；
}
//使通知栏透明
如果（Build.VERSION.SDK_INT>=21）{
getWindow（）.getDecorView（）.SetSystemMivibility（View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_全屏）；
}
setContentView（R.layout.activity_welcome）；
viewPager=（viewPager）findViewById（R.id.view\u pager）；
dotsLayout=（LinearLayout）findViewById（R.id.layoutDots）；
btnSkip=（按钮）findViewById（R.id.btn\u skip）；
btnNext=（按钮）findViewById（R.id.btn_next）；
//所有欢迎滑块的布局
//如果需要，再添加一些布局
布局=新int[]{
R.layout.welcome_幻灯片1，
R.layout.welcome_幻灯片2，
R.layout.welcome_幻灯片3，
R.layout.welcome_slide4}；
//添加底点
添加点（0）；
//使通知栏透明
changeStatusBarColor（）；
myViewPagerAdapter=新的myViewPagerAdapter（）；
设置适配器（myViewPagerAdapter）；
viewPager.addOnPageChangeListener（viewPagerPageChangeListener）；
btnSkip.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
启动主屏幕（）；
}
});
btnNext.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
//检查最后一页
//如果最后一页主页将启动
int current=getItem（+1）；
if（当前0）
点[currentPage].setTextColor（颜色活动[currentPage]）；
}
私有整数getItem（整数i）{
返回viewPager.getCurrentItem（）+i；
}
私有void启动主屏幕（）{
prefManager.setFirstTimeLaunch（false）；
startActivity（新意图（WelcomeActivity.this、MainActivity.class））；
完成（）；
}
//viewpager更改侦听器
ViewPager.OnPageChangeListener viewPagerPageChangeListener=新建ViewPager.OnPageChangeListener（）{
@凌驾
已选择页面上的公共无效（内部位置）{
添加点（位置）；
//更改“下一步”按钮文本“下一步”/“明白了”
如果（位置==layouts.length-1）{
//最后一页。制作按钮文本以获取它
setText（getString（R.string.start））；
btnSkip.setVisibility（View.GONE）；
}否则{
//还有几页
setText（getString（R.string.next））；
btnSkip.setVisibility（View.VISIBLE）；
}
}
@凌驾
已滚动页面上的公共void（int arg0、float arg1、int arg2）{
}
@凌驾
公共无效onPageScrollStateChanged（int arg0）{
}
};
/**
*使通知栏透明
*/
私有void changeStatusBarColor（）{
if（Build.VERSION.SDK\u INT>=Build.VERSION\u code.LOLLIPOP）{
Window=getWindow（）；
添加标志（WindowManager.LayoutParams.FLAG\u绘图\u系统\u栏\u背景）；
window.setStatusBarColor（Color.TRANSPARENT）；
}
}
/**
*查看寻呼机适配器
*/
公共类MyViewPagerAdapter扩展了PagerAdapter{
私人停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场；
公共MyViewPagerAdapter（）{
}
@凌驾
公共对象实例化项（视图组容器，int位置）{
layoutInflater=（layoutInflater）getSystemService（Context.LAYOUT\u INFLATER\u SERVICE）；
视图=布局更平。充气（布局[位置]，容器，假）；
container.addView（视图）；
返回视图；
}
@凌驾
public int getCount（）{
返回布局。长度；
}
@凌驾
酒吧
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.android.smartswitch">

<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"
        android:label="@string/app_name"
        android:theme="@style/AppTheme.NoActionBar">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

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

    <activity
        android:name=".WelcomeActivity">
        <intent-filter>
            <action android:name="android.intent.action.VIEW" />

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

    <activity
        android:name=".temp_screen"
        android:label="@string/title_activity_temp_screen"
        android:theme="@style/AppTheme.NoActionBar" />
    <activity
        android:name=".logging_screen"
        android:label="@string/title_activity_logging_screen"
        android:theme="@style/AppTheme.NoActionBar" />
    <activity
        android:name=".humidity_settings"
        android:label="@string/title_activity_humidity_settings"
        android:theme="@style/AppTheme.NoActionBar" />
    <activity
        android:name=".random_delay"
        android:label="@string/title_activity_random_delay"
        android:theme="@style/AppTheme.NoActionBar" />

</application>

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

//removed super.onCreate(savedInstanceState);
//removed setContentView(R.layout.activity_welcome);

 super.onCreate(savedInstanceState);
`setContentView(R.layout.activity_welcome);`

super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_welcome);

   // super.onCreate(savedInstanceState);

    // Checking for first time launch - before calling setContentView()
    prefManager = new slidingScreenLauncher(this);
    if (!prefManager.isFirstTimeLaunch()) {
        launchHomeScreen();
        finish();
    }

    // Making notification bar transparent
    if (Build.VERSION.SDK_INT >= 21) {
        getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
    }

   // setContentView(R.layout.activity_welcome);