Question

我正在制作一个翻译应用程序，我想在其中更新文本视图，但它没有按照我的意愿进行。

final audioTranslate at[] = new audioTranslate[1];
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_audio_translate);
    tv = (TextView) findViewById(R.id.textView11);
    spokentext = (TextView) findViewById(R.id.textView12);
    translatedtext = (TextView) findViewById(R.id.textView13);
    at[0] = this;
    start = (Button) findViewById(R.id.Start);
    start.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Button b = (Button) v;
            if (b.getText().toString().equals("Start")) {
                //code
            }
            else{
                tv.setText("");  //these all 3 operations are happening after transfer method is finished.
                b.setText("Wait");  
                b.setEnabled(false);
                transfer();
            }
        }
    });
}

void transfer() {
    Thread t = new Thread() {
        public void run() {
            //socket connection
            //it is giving exception on below line too.
            //Only the original thread that created a view hierarchy can touch its views. 
            //java.lang.RuntimeException
            at[0].spokentext.setText(spoken);
        }
    };
t.start();
}

这是我的布局文件供参考：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_audio_translate"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="diverse.technologies.transcriber.audioTranslate">

<ScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TableLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true">

        <TableRow
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center_horizontal">

            <Button
                android:text="Start"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/Start" />
        </TableRow>

        <TableRow
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginTop="20dp"
            android:gravity="center_horizontal">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/textView11"
                android:textColor="@color/colorAccent"
                android:textSize="24sp" />
        </TableRow>

        <TableRow
            android:layout_width="match_parent"
            android:layout_height="match_parent" >

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/textView12"
                android:textSize="26sp"
                android:fontFamily="serif-monospace"
                android:textStyle="normal|bold" />
        </TableRow>

        <TableRow
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginTop="5px">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/textView13"
                android:textSize="24sp"/>
        </TableRow>

    </TableLayout>
</ScrollView>

</RelativeLayout>

我没有得到上述异常的错误。我正在使用具有textview的视图的对象。请帮忙。

Answer 1

普通工作线程无法修改TextView等UI元素。在UI线程中运行代码at[0].spokentext.setText(spoken);。在你的run方法中写一下

runOnUiThread(new Runnable() {
                @Override
                public void run() {//Your code}}

但是我不建议使用这种类型的本机java编码。使用Handler或AsyncTask

Answer 2

将此用作转移方法：

void transfer() {
Thread t = new Thread() {
    public void run() {
        //socket connection
        //it is giving exception on below line too.
        //Only the original thread that created a view hierarchy can touch its views. 
        //java.lang.RuntimeException
        spokentext.post(new Runnable() {
        @Override
        public void run() {
            at[0].spokentext.setText(spoken);
        }
    });

    }
};
t.start();
}

Answer 3

就像@Pavneet_Singh所说的那样，你无法从另一个线程更新你的UI。您可能希望这样做，而不是调用transfer()。

public class YourActivity {
    ...
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        ...
        start.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Button b = (Button) v;
                if (b.getText().toString().equals("Start")) {
                    //code
                } else {
                    tv.setText("");  //these all 3 operations are happening after transfer method is finished.
                    b.setText("Wait");  
                    b.setEnabled(false);
                    new RetrieveSpokenTextTask().execute();
                }
            }
        });
    }

    private class RetrieveSpokenTextTask extends AsyncTask<Void,Void,String> {
        @Override
        public String doInBackground(Void... params) {
            String spoken = "the value you would like to assign to the TextView";
            return spoken;
        }

        @Override
        public void postExecute(String text) {
            // the `text` variable has now the string you returned in `doInBackground`
            spokentext.setText(text);
        }
    }
}

无法立即更新textview

3 个答案: