如何将xml中的按钮链接到类中的java操作

Question

对开发非常陌生！

我基本上想将我在 XML 中创建的按钮链接到相应类中的 java 代码。

我想要实现的是放置在我的 web 视图上方的按钮，该按钮具有文本“开始录制”，一旦单击，音频录制功能将启动，然后文本将变为“停止录制”。

我遇到的问题是，我的应用程序屏幕上有一个按钮，但是上面没有文字，当我单击该按钮时，我的应用程序崩溃了。

以下是该类的代码：

public class Drugs extends AppCompatActivity {

WebView myBrowser;

private static final String LOG_TAG = "Recording";
private static String mFileName = null;


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

private void onRecord(boolean start) {
    if (start) {
        startRecording();
    } else {
        stopRecording();
    }
}

private void startRecording() {
    mRecorder = new MediaRecorder();
    mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
    mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
    mRecorder.setOutputFile(mFileName);
    mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);

    try {
        mRecorder.prepare();
    } catch (IOException e) {
        Log.e(LOG_TAG, "prepare() failed");
    }

    mRecorder.start();
}

private void stopRecording() {
    mRecorder.stop();
    mRecorder.release();
    mRecorder = 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);
    }
}

public Drugs() {
    mFileName = Environment.getExternalStorageDirectory().getAbsolutePath();
    mFileName += "/audiorecordtest.3gp";
}





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

    myBrowser = (WebView) findViewById(R.id.mybrowser);
    myBrowser.loadUrl("file:///android_asset/drugs.html");
    myBrowser.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);

    Button btndrugslaw = (Button) findViewById(R.id.drugslaw);

    btndrugslaw.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {
            Intent intentdruglaw = new Intent(Drugs.this, DrugLaw.class);
            startActivity(intentdruglaw);
        }
    });

}

这是xml的代码

<ScrollView
android:layout_height="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent">

<RelativeLayout

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"
tools:context="kyr.com.knowyourrights.Drugs"
android:orientation="vertical"
>

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/RecordButton"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:onClick="onClick"
    >

</Button>

<WebView
    android:id="@+id/mybrowser"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
  >

</WebView>

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/drugslaw"
    android:text="Take me to the law"
    android:layout_below="@id/mybrowser"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true" />

</RelativeLayout>


</ScrollView>

Answer 1

有很多方法。

例如

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/RecordButton"
    android:layout_above="@+id/mybrowser"
    android:layout_alignParentTop="true"
    android:onClick="recordClick"
    android:layout_centerHorizontal="true">

然后在你的课堂上

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

    myBrowser = (WebView) findViewById(R.id.mybrowser);
    myBrowser.loadUrl("file:///android_asset/drugs.html");
    myBrowser.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);

    Button btndrugslaw = (Button) findViewById(R.id.drugslaw);

    btndrugslaw.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {
            Intent intentdruglaw = new Intent(Drugs.this, DrugLaw.class);
            startActivity(intentdruglaw);
        }
    });

public void recordClick(View view){

    // your code to handle click
}

}

如果你有多个按钮

    public void recordClick(View view){

    switch(view.getId())

    //HERE YOU WILL PASS THE ID OF YOUR BUTTONS
    case R.id.firstButton:
        //Code to handle click
    case R.id.secondButton:
        //Code to handle second button click

    // AND SO ON
}

Answer 2

在 XML 中添加 OnClick 方法

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/RecordButton"
    android:layout_above="@+id/mybrowser"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:onClick="RecordButton"
    android:text="Start"
    >

在 Java 中

    Button btn = (Button) findViewById(R.id.RecordButton);

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


    public void RecordButton(View v) {
           Button b = (Button)v;
          if(b.getText().toString().equals("Start")){
             onRecord(true);
             b.setText("Stop");
          }else{
             onRecord(false);
             b.setText("Start");
    }

Answer 3

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/RecordButton"
    android:layout_above="@+id/mybrowser"
    android:layout_alignParentTop="true"
    android:onClick="recordClick"
    android:layout_centerHorizontal="true">

实现 View.OnClickLIsener

public class Drugs extends AppCompatActivity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_drugs);
    Button btndrugs = (Button) findViewById(R.id.RecordButton);
    btndurgs.setOnClickListener(this);
      }
   public void onClick(View v) {
        switch (v.getId()){
            case(R.id.RecordButton):
your logic here
    break;
    }
}}