Question

我有两个类，一个叫做Main1843，另一个是JsonParse。当我复制与main1843相同的所有课程时，一切正常。但我更喜欢分开课程和整洁。问题是我无法运行下面的代码。没有显示错误，只是app停止运行。（清单文件具有权限）

因为它是一个简短的程序，你可以检查每一行。

Main1843课程：

public class Main1843 extends Activity implements View.OnClickListener {
private Button button;
private TextView tv;
private EditText et;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main1843);

    tv = (TextView) findViewById(R.id.panel);
    et = (EditText) findViewById(R.id.editText1);
    button = (Button) findViewById(R.id.button1);

    button.setOnClickListener(this);
}

public void onClick(View v) {
    String text;
    text = et.getText().toString();
    tv.append(text);
    tv.append("\n");
    new JsonParse().execute();
}

protected void putScreen(String t) {
    tv.append(t);
}   
}

另一个类（JsonParse）扩展了AsyncTask＆lt;＆gt; ;

public class JsonParse extends AsyncTask{
private String yazi;
protected String yazi2;
protected String id;

private String TAG = "JWP";


@Override
protected Object doInBackground(Object[] objects) {
    return POST("http://somewebsite/show.php");
}


public String POST(String url) {
    String result = "";
    HttpClient client = new DefaultHttpClient();
    HttpPost post = new HttpPost(url);
    Main1843 m = new Main1843();

    try {
        HttpResponse response = client.execute(post);
        InputStream inputStream = response.getEntity().getContent();
        if (inputStream != null) {
            String text = "";
            result = convertInputStreamToString(inputStream);
            Log.d(TAG, result);
            JSONArray reader = new JSONArray(result);
            for (int i = 0; i < reader.length(); i++) {
                JSONObject data = reader.getJSONObject(i);
                id = data.getString("id");
                yazi = data.getString("yazi");
                yazi2 = data.getString("yazi2");

                text += yazi;
                text += " ";
            }
            m.putScreen(text);
        } else
            result = "Did not work";
        return result;
    } catch (IOException e) {
        e.printStackTrace();
        return "Exception 1";
    } catch (Exception e) {
        e.printStackTrace();
        return "haha";
    }
}


private String convertInputStreamToString(InputStream inputStream) {
    BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));
    String line = "";
    String result = "";

    try {
        while ((line = br.readLine()) != null)
            result += line;
        br.close();
        return result;
    } catch (IOException e) {
        e.printStackTrace();
        return "Exception";
    }

}
}

感谢您的时间。

Answer 1

评论解决了问题

“您需要将活动上下文传递到AsyncTask以调用其上的方法，或者您可以调用您的活动实现的侦听器，或者您可以使用localbroadcast。” KenWolf

@ShaikhMohammedShariq shared a similar problem answer

JSON解析运行时错误 - 不同的类

1 个答案: