Question

我继承了一个基本没有Java编程经验的Android Studio项目。我一直在使用免费的在线教程和The Big Nerd Ranch指南书教我自己，我知道如何使用相关的.java类切换到不同的.xml视图，但我想打开一个与之相关的新.xml视图相同的.java类。

基本上我只想修改我从蓝牙设备读取信息的应用程序，并在TextView中显示测量结果以及“通过/失败”显示，以显示通过/失败显示和“查看日志”按钮单击时，将转到包含带有所有结果的TextView的新.xml。

我试图避免使用不同的.java类，因为我希望所有项目具有相同的功能，只是在不同的.xml视图中，我担心将我已经拥有的所有内容都移动到新的中。 java类只会产生比我现有的问题更多的问题。

我不确定是否有必要，但这是我的代码：从我的首屏开始

frament_bluetooth_scanner.xml:
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <Button
        android:id="@+id/go_to_log"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="16dp"
        android:text="@string/view_log"
        android:textSize="20dp"/>

    <View
        android:id="@+id/view"
        android:layout_width="fill_parent"
        android:layout_height="2dp"
        android:background="#ccc"/>

</LinearLayout>

<LinearLayout
    android:orientation="horizontal"
    android:paddingTop="@dimen/margin_small"
    android:paddingLeft="4dp"
    android:paddingRight="4dp"
    android:paddingBottom="4dp"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="center_horizontal">


    <Button
        android:id="@+id/button_present"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#ffc4ab"
        android:clickable="false"
        android:padding="16dp"
        android:text="NO TAGGANT DETECTED"
        android:textSize="26dp"
        />

</LinearLayout>

button_present都会激活蓝牙测试并显示通过/未通过结果。它存在并正在按预期工作。

go_to_log是我添加的按钮，我希望它点击以转到下一个视图：

view_list.xml:
<FrameLayout
    android:orientation="horizontal"
    android:paddingLeft="4dp"
    android:paddingRight="4dp"
    android:layout_width="match_parent"
    android:layout_height="fill_parent"
    android:visibility="visible"
    android:layout_gravity="center_horizontal">

    <Button
        android:layout_width="fill_parent"
        android:layout_height="40dp"
        android:text="@string/clear_log"
        android:id="@+id/button_clear_log" />

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:paddingTop="40dp"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:id="@+id/scanLogView"
        android:maxLines = "4096"
        android:text="@string/app_name"
        android:scrollbars = "vertical"
        android:layout_gravity="center_horizontal"/>

</FrameLayout>

所有这些代码最初都在fragment_bluetooth_scanner.xml文件中，一切都按预期工作。唯一的问题是TextView难以阅读，因为它显示了所有测试的信息，直到它被清除，并且即使是单个测试，所有信息都不适合屏幕。我想将其更改为更加用户友好。

主.java文件很长，所以我会发布它的相关部分。来自ScannerFragment.java：

 @Override
    public void onViewCreated(View view, @Nullable Bundle 
savedInstanceState) {
    SP = PreferenceManager.getDefaultSharedPreferences(getContext());

    mPowerOffButton = (Button) view.findViewById(R.id.button_poweroff);
    mDisconnectButton = (Button) view.findViewById(R.id.button_disconnect);
    mConnectButton = (Button) view.findViewById(R.id.button_connect);
    mPresence = (Button) view.findViewById(R.id.button_present);

    mBattery = (ProgressBar) view.findViewById(R.id.progressBar);

    mBlinkConnect = (Button) view.findViewById(R.id.button_connectionblink);
    mBlinkData = (Button) view.findViewById(R.id.button_communication);
    mClearLog = (Button) view.findViewById(R.id.button_clear_log);

    mDeviceName = (Button) view.findViewById(R.id.button_devicename);
    mDeviceSN = (Button) view.findViewById(R.id.button_devicesn);
    mBatteryPerc = (TextView) view.findViewById(R.id.label_batterypct);

    mReadingLog  = (TextView) view.findViewById(R.id.scanLogView);
    mReadingLog.setMovementMethod(new ScrollingMovementMethod());
    mReadingLog.setText(readFromFile());

    mViewLog = (Button)view.findViewById(R.id.go_to_log);


    telephonyManager = (TelephonyManager)getContext().getSystemService(Context.TELEPHONY_SERVICE);

    initLocationService(this.getContext());

    final ActionBar actionBar = getActivity().getActionBar();
    if (null == actionBar) {
        return;
    }
    final Drawable D = getResources().getDrawable(R.drawable.stardust2);
    actionBar.setBackgroundDrawable(D);
    actionBar.setTitle("");



}

private void setupScanner() {
    Log.d(TAG, "setupScanner()");

    // Initialize the send button with a listener that for click events
    mPowerOffButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            if(isIris) {
                publishMessage(Constants.COMMAND_POWEROFF_IRIS);
            } else {
                publishMessage(Constants.COMMAND_POWEROFF);
            }
            mScannerService.stop();
        }
    });

    // Initialize the send button with a listener that for click events
    mDisconnectButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            // Send a message using content of the edit text widget
            publishMessage(Constants.COMMAND_DISCONNECT);
            mScannerService.stop();
        }
    });

    // Initialize the send button with a listener that for click events
    mConnectButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            // Send a message using content of the edit text widget
            publishMessage(Constants.COMMAND_ON_CONNECT);
        }
    });

    mClearLog.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            // Send a message using content of the edit text widget
            mReadingLog.setText("");
            if(SP.getBoolean("writeToFile", true)) {
                writeToFile("", "", false);
            }
        }
    });

这是所有现有行动发生的地方。阻止我创建一个新的.java类的主要原因是整个类都使用mReadingLog，我不明白此时读取/写入文本文件非常好，所以我想避免改变任何与该过程有关的事情。

我过去经历了this one之类的教程，但在与同一xml相关联时，我找不到有关如何打开新.java文件的任何内容类。这可能吗？

Answer 1

......好的，所以这次我实际上读了......大声笑......你可以在一个班级中创建功能。将其设为静态，然后您可以在任何地方调用这些函数。

这就是我的工作

{
  "name": "portfolio",
  "version": "1.0.0",
  "description": "Displaying self skills",
  "main": "index.html",
  "scripts": {
    "start": "npm run lite",
    "test": "echo \"Error: no test specified\" && exit 1",
    "lite": "lite-server"
  },
  "author": "Vikranth Kanumuru",
  "license": "ISC",
  "devDependencies": {
    "lite-server": "^2.3.0"
  },
  "dependencies": {
    "bootstrap": "^4.0.0-alpha.6",
    "font-awesome": "^4.7.0"
  }
}

所以在我的任何课程中，我都可以这样打电话：

2017-08-18T20:23:16.489546+00:00 app[web.1]:
2017-08-18T20:23:16.489568+00:00 app[web.1]: > portfolio@1.0.0 start /app
2017-08-18T20:23:16.489569+00:00 app[web.1]: > npm run lite
2017-08-18T20:23:16.489570+00:00 app[web.1]:
2017-08-18T20:23:17.508804+00:00 app[web.1]:
2017-08-18T20:23:17.508810+00:00 app[web.1]: > portfolio@1.0.0 lite /app
2017-08-18T20:23:17.546486+00:00 app[web.1]: npm ERR! code ELIFECYCLE
2017-08-18T20:23:17.508812+00:00 app[web.1]:
2017-08-18T20:23:17.518042+00:00 app[web.1]: sh: 1: lite-server: not found
2017-08-18T20:23:17.547397+00:00 app[web.1]: npm ERR! portfolio@1.0.0 lite: `lite-server`
2017-08-18T20:23:17.508811+00:00 app[web.1]: > lite-server
2017-08-18T20:23:17.552475+00:00 app[web.1]: npm ERR! Failed at the portfolio@1.0.0 lite script.
2017-08-18T20:23:17.547633+00:00 app[web.1]: npm ERR! spawn ENOENT
2017-08-18T20:23:17.547922+00:00 app[web.1]: npm ERR!
2017-08-18T20:23:17.555969+00:00 app[web.1]: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
2017-08-18T20:23:17.545582+00:00 app[web.1]: npm ERR! file sh
2017-08-18T20:23:17.546830+00:00 app[web.1]: npm ERR! errno ENOENT
2017-08-18T20:23:17.547103+00:00 app[web.1]: npm ERR! syscall spawn
2017-08-18T20:23:17.570546+00:00 app[web.1]:
2017-08-18T20:23:17.570802+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2017-08-18T20:23:17.623863+00:00 app[web.1]: npm ERR! portfolio@1.0.0 start: `npm run lite`
2017-08-18T20:23:17.570948+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2017-08-18T20_23_17_531Z-debug.log
2017-08-18T20:23:17.623455+00:00 app[web.1]: npm ERR! code ELIFECYCLE
2017-08-18T20:23:17.623689+00:00 app[web.1]: npm ERR! errno 1
2017-08-18T20:23:17.624496+00:00 app[web.1]: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
2017-08-18T20:23:17.625545+00:00 app[web.1]:
2017-08-18T20:23:17.624015+00:00 app[web.1]: npm ERR! Exit status 1
2017-08-18T20:23:17.625895+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2017-08-18T20:23:17.624183+00:00 app[web.1]: npm ERR!
2017-08-18T20:23:17.626003+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2017-08-18T20_23_17_610Z-debug.log
2017-08-18T20:23:17.624342+00:00 app[web.1]: npm ERR! Failed at the portfolio@1.0.0 start script.
2017-08-18T20:23:17.788754+00:00 heroku[web.1]: Process exited with status 1
2017-08-18T20:23:17.804560+00:00 heroku[web.1]: State changed from starting to crashed
2017-08-18T20:24:22.252405+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=hidden-oasis-28106.herokuapp.com request_id=34b1dd02-e75a-400b-a7a6-7b611f60372f fwd="157.50.8.21" dyno= connect= service= status=503 bytes= protocol=https
2017-08-18T20:29:50.602309+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=hidden-oasis-28106.herokuapp.com request_id=3f4f9a84-3081-4b96-a078-89f404ddfeb3 fwd="157.50.8.21" dyno= connect= service= status=503 bytes= protocol=https
2017-08-18T20:35:04.704313+00:00 heroku[web.1]: State changed from crashed to starting
2017-08-18T20:35:06.664888+00:00 heroku[web.1]: Starting process with command `npm start`
2017-08-18T20:35:10.881400+00:00 app[web.1]:
2017-08-18T20:35:10.881410+00:00 app[web.1]: > npm run lite
2017-08-18T20:35:10.881410+00:00 app[web.1]: > portfolio@1.0.0 start /app
2017-08-18T20:35:10.881411+00:00 app[web.1]:
2017-08-18T20:35:11.913060+00:00 app[web.1]:
2017-08-18T20:35:11.913072+00:00 app[web.1]: > portfolio@1.0.0 lite /app
2017-08-18T20:35:11.913072+00:00 app[web.1]: > lite-server
2017-08-18T20:35:11.913073+00:00 app[web.1]:
2017-08-18T20:35:11.920446+00:00 app[web.1]: sh: 1: lite-server: not found
2017-08-18T20:35:11.944906+00:00 app[web.1]: npm ERR! file sh
2017-08-18T20:35:11.945211+00:00 app[web.1]: npm ERR! code ELIFECYCLE
2017-08-18T20:35:11.945442+00:00 app[web.1]: npm ERR! errno ENOENT
2017-08-18T20:35:11.945920+00:00 app[web.1]: npm ERR! portfolio@1.0.0 lite: `lite-server`
2017-08-18T20:35:11.945674+00:00 app[web.1]: npm ERR! syscall spawn
2017-08-18T20:35:11.946095+00:00 app[web.1]: npm ERR! spawn ENOENT
2017-08-18T20:35:11.946309+00:00 app[web.1]: npm ERR!
2017-08-18T20:35:11.946516+00:00 app[web.1]: npm ERR! Failed at the portfolio@1.0.0 lite script.
2017-08-18T20:35:11.968813+00:00 app[web.1]: npm ERR! code ELIFECYCLE
2017-08-18T20:35:11.946693+00:00 app[web.1]: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
2017-08-18T20:35:11.948500+00:00 app[web.1]:
2017-08-18T20:35:11.948745+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2017-08-18T20:35:11.948891+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2017-08-18T20_35_11_930Z-debug.log
2017-08-18T20:35:11.969079+00:00 app[web.1]: npm ERR! errno 1
2017-08-18T20:35:11.969447+00:00 app[web.1]: npm ERR! Exit status 1
2017-08-18T20:35:11.969275+00:00 app[web.1]: npm ERR! portfolio@1.0.0 start: `npm run lite`
2017-08-18T20:35:11.969622+00:00 app[web.1]: npm ERR!
2017-08-18T20:35:11.969809+00:00 app[web.1]: npm ERR! Failed at the portfolio@1.0.0 start script.
2017-08-18T20:35:11.970006+00:00 app[web.1]: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
2017-08-18T20:35:11.971505+00:00 app[web.1]:
2017-08-18T20:35:11.971728+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2017-08-18T20:35:11.971880+00:00 app[web.1]: npm ERR!     /app/.npm/_logs/2017-08-18T20_35_11_963Z-debug.log
2017-08-18T20:35:12.105152+00:00 heroku[web.1]: State changed from starting to crashed
2017-08-18T20:35:12.090364+00:00 heroku[web.1]: Process exited with status 1
2017-08-18T20:37:53.000000+00:00 app[api]: Build started by user saivicky2015@gmail.com
2017-08-18T20:38:19.813964+00:00 heroku[web.1]: State changed from crashed to starting
2017-08-18T20:38:19.435208+00:00 app[api]: Deploy bdaf4749 by user saivicky2015@gmail.com
2017-08-18T20:38:19.435208+00:00 app[api]: Release v7 created by user saivicky2015@gmail.com
2017-08-18T20:37:53.000000+00:00 app[api]: Build succeeded
2017-08-18T20:38:23.462016+00:00 heroku[web.1]: Starting process with command `npm start`
2017-08-18T20:38:27.290378+00:00 app[web.1]:
2017-08-18T20:38:27.290394+00:00 app[web.1]: > portfolio@1.0.0 start /app
2017-08-18T20:38:27.290395+00:00 app[web.1]: > npm run lite
2017-08-18T20:38:27.290395+00:00 app[web.1]:
2017-08-18T20:38:28.147286+00:00 app[web.1]:
2017-08-18T20:38:28.147298+00:00 app[web.1]: > portfolio@1.0.0 lite /app
2017-08-18T20:38:28.147299+00:00 app[web.1]: > lite-server
2017-08-18T20:38:28.147299+00:00 app[web.1]:
2017-08-18T20:38:29.567913+00:00 app[web.1]: Did not detect a `bs-config.json` or `bs-config.js` override file. Using lite-server defaults...
2017-08-18T20:38:29.570317+00:00 app[web.1]: ** browser-sync config **
2017-08-18T20:38:29.574243+00:00 app[web.1]: { injectChanges: false,
2017-08-18T20:38:29.574245+00:00 app[web.1]:   files: [ './**/*.{html,htm,css,js}' ],
2017-08-18T20:38:29.574246+00:00 app[web.1]:   watchOptions: { ignored: 'node_modules' },
2017-08-18T20:38:29.574247+00:00 app[web.1]:   server: { baseDir: './', middleware: [ [Function], [Function] ] } }
2017-08-18T20:38:29.780891+00:00 app[web.1]: [Browsersync] Access URLs:
2017-08-18T20:38:29.781317+00:00 app[web.1]:  ---------------------------------------
2017-08-18T20:38:29.781937+00:00 app[web.1]:        Local: http://localhost:3000
2017-08-18T20:38:29.782215+00:00 app[web.1]:     External: http://172.18.222.246:3000
2017-08-18T20:38:29.782426+00:00 app[web.1]:  ---------------------------------------
2017-08-18T20:38:29.782691+00:00 app[web.1]:           UI: http://localhost:3001
2017-08-18T20:38:29.782955+00:00 app[web.1]:  UI External: http://172.18.222.246:3001
2017-08-18T20:38:29.783151+00:00 app[web.1]:  ---------------------------------------
2017-08-18T20:38:29.783535+00:00 app[web.1]: [Browsersync] Serving files from: ./
2017-08-18T20:38:29.796322+00:00 app[web.1]: [Browsersync] Watching files...
2017-08-18T20:38:30.061505+00:00 app[web.1]: [Browsersync] Couldn't open browser (if you are using BrowserSync in a headless environment, you might want to set the open option to false)
2017-08-18T20:39:23.645673+00:00 heroku[web.1]: Process exited with status 137
2017-08-18T20:39:23.659964+00:00 heroku[web.1]: State changed from starting to crashed

Answer 2

我不确定我是否理解。但是如果您想通过按下按钮或......来切换不同的视图，您可以使用ViewFilpper 在活动布局中将其添加为视图。

<ViewFlipper
   android:id="@+id/simpleViewFlipper"
   android:layout_width="match_parent"
   android:layout_height="wrap_content">

   <!--   Add View’s Here Which You Want to Flip -- > 
   <include layout="First"/>
   <include layout="Second"/>
   <include layout="third"/>
   <!-- ... -->

</ ViewFlipper >

如何使用单个java类在多个视图之间切换？

2 个答案: