java - android中表单程序生成的布局到XML布局

Question

最近我研究了android示例中的代码，它是录制音频的示例，并且有两个自定义类扩展按钮，例如RecordButton和PlayButton

代码如下:

public class AudioRecordTest extends Activity
{
    private static final String LOG_TAG = "AudioRecordTest";
    private static String mFileName = null;

    private RecordButton mRecordButton = null;
    private MediaRecorder mRecorder = null;

    private PlayButton   mPlayButton = null;
    private MediaPlayer   mPlayer = null;

    class RecordButton extends Button {
        boolean mStartRecording = true;

        OnClickListener clicker = new OnClickListener() {
            public void onClick(View v) {
                onRecord(mStartRecording);
                if (mStartRecording) {
                    setText("Stop recording");
                } else {
                    setText("Start recording");
                }
                mStartRecording = !mStartRecording;
            }
        };

        public RecordButton(Context ctx) {
            super(ctx);
            setText("Start recording");
            setOnClickListener(clicker);
        }
    }

    class PlayButton extends Button {
        boolean mStartPlaying = true;

        OnClickListener clicker = new OnClickListener() {
            public void onClick(View v) {
                onPlay(mStartPlaying);
                if (mStartPlaying) {
                    setText("Stop playing");
                } else {
                    setText("Start playing");
                }
                mStartPlaying = !mStartPlaying;
            }
        };

        public PlayButton(Context ctx) {
            super(ctx);
            setText("Start playing");
            setOnClickListener(clicker);
        }
    }



    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);

        LinearLayout ll = new LinearLayout(this);
        mRecordButton = new RecordButton(this);
        ll.addView(mRecordButton,
            new LinearLayout.LayoutParams(
                ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT,
                0));
        mPlayButton = new PlayButton(this);
        ll.addView(mPlayButton,
            new LinearLayout.LayoutParams(
                ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT,
                0));
        setContentView(ll);
    }


}

我想将其更改为 XML ，但是，它返回类未找到的错误

 Suppressed: java.lang.ClassNotFoundException: com.example.user.test.MainActivity.RecordButton

Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available

在 XML 设计器 View 中，它还有一个

 java.lang.LinkageError (loader attempt a duplicate class definition for name : RecordButton)

这是我尝试构建的 XML:

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center"
    tools:context=".MainActivity">

    <com.example.user.test.MainActivity.RecordButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/rec_btn" />

    <com.example.user.test.MainActivity.PlayButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/play_btn" />

</LinearLayout>

有没有我遗漏的东西，我检查了包名称是否正确。我该如何解决？

更新: list

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

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.RECORD_AUDIO" />

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

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

Answer 1

首先，尝试经典的清理/重建项目。它将确保您的代码确实存在问题，而不是调试器存在问题

然后，我建议您在不同的文件中声明两个类，这样会更具可读性，而且在使用内部类时会更频繁地出现问题。

我发现您的问题与这篇文章中的问题有关:extend button android, xml layout ，你尝试过给出的答案吗？

I understand "(included into another class)" as you have an inner class RecordButton.

Assuming your package is AudioRecordTest.test (which would be a very bad name choice) and your RecordButton class is an inner class of AudioRecord.class, you need to use:

BTW: any particular reason you create it as an inner class instead of having it separate?

您正在为按钮使用内部类。那么你使用它的方式就不同了。使用上一篇文章或将您的类添加到不同的 java 文件中。