Android setText 无法显示来自数据库的字符串

Question

我的应用程序可以选择数据并将其显示到 Log.e 中，但不能将其设置到 textViews 中。这是什么原因？

我想在 OnClick 事件之后显示数据，将可见性设置为可见。

final TextView txv_yes = (TextView) findViewById(R.id.vou);
final TextView txv_no = (TextView) findViewById(R.id.nao_vou);
final TextView txv_maybe = (TextView) findViewById(R.id.talvez);
show_count = (RelativeLayout) findViewById(R.id.show_block);

count_vou = (TextView) findViewById(R.id.count_vou);
count_nao = (TextView) findViewById(R.id.count_nao_vou);
count_talvez = (TextView) findViewById(R.id.count_talvez);

txv_yes.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
    yes = txv_yes.getText().toString();
    new insertYes().execute();
    new select().execute();

    runOnUiThread(new Runnable() {
      public void run() {
        setVisible();
                }
            });

    }
});

public class select extends AsyncTask<String, Boolean, Boolean>{

    @Override
    protected Boolean doInBackground(String... params) {

        ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
        nameValuePairs.add(new BasicNameValuePair("e_id", subString));

        try
        {
        HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("http://website.com/includes/select_counter.php");
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            HttpResponse response = httpclient.execute(httppost); 
            HttpEntity entity = response.getEntity();
            inputStream = entity.getContent();
            Log.e("pass 1", "connection success ");
    }
        catch(Exception e)
    {
            Log.e("Fail 1", e.toString());
            Toast.makeText(getApplicationContext(), "Invalid IP Address",
            Toast.LENGTH_LONG).show();
    }     

        try
        {
            BufferedReader reader = new BufferedReader
                (new InputStreamReader(inputStream,"UTF-8"));
                StringBuilder sb = new StringBuilder();
                while ((line = reader.readLine()) != null)
        {
                sb.append(line + "\n");
            }
                inputStream.close();
                result = sb.toString();
            Log.e("pass 2", "connection success ");
    }
        catch(Exception e)
        {
        Log.e("Fail 2", e.toString());
    }     

    try
        {
            JSONObject json_data = new JSONObject(result);
            get_yes = (json_data.getString("Vou"));
            get_no = (json_data.getString("Nao_Vou"));
            get_maybe = (json_data.getString("Talvez"));
            Log.e("pass 3", "Vou : "+ get_yes);
            Log.e("pass 4", "Não Vou : "+ get_no);
            Log.e("pass 5", "Talvez: "+ get_maybe);

        }
        catch(Exception e)
        {
            Log.e("Fail 3", e.toString());
        }

        return null;
    }
}

public boolean setVisible() {
    show_count.setVisibility(View.VISIBLE);
    count_vou.setText(get_yes);
    count_nao.setText(get_no);
    count_talvez.setText(get_yes);

    return true;

}

我在 Logs.e 之后的 try/catch 中有这段代码，但问题是一样的：

count_vou.setText(get_yes);
count_nao.setText(get_no);
count_talvez.setText(get_yes);

Answer 1

setVisible() 在服务器调用完成之前运行，它在您实际获取值之前设置值。

因此，不要在触发异步任务后立即调用此代码，而是在 Log 语句之后从异步任务中调用。可以使用异步任务的 onPostExecute 方法。

runOnUiThread（新可运行（）{ 公共无效运行（）{ 设置可见（）； } }); }

Answer 2

在您的异步任务完成之前调用 setVisible() 方法。因此您无法在 setVisible() 方法中获取数据库值。

在你的 select asynctask 中实现 onPostExecute 方法，然后在其中调用 setVisible() 方法。

@Override
   protected void onPostExecute(String result) {
      setVisible();
   }

希望对你有帮助！

Answer 3

尝试使用this.count_vou.setText(get_yes); 或activityname.this.count_vou.setText(get_yes)

您似乎在 runOnUI 线程中使用它，但它无法在 runOnUi 方法中访问。

Answer 4

解决方案 1。选择异步任务完成后调用 setVisible() 函数。移除 Runnable 线程

新的选择（）。执行（）； 设置可见（）；

解决方案 2。你也可以在 asynctask 中调用 setVisible()

@Override

protected void onPostExecute(Boolean result) {

    super.onPostExecute(result); 
    setVisible();

   }

Answer 5

解决方案 1：- 在 AsyncTask 中分配所有值后调用 setVisible() 方法。 代码如下。从 onClickListener 中移除 setVisible() 方法调用

试试下面的代码。 注意：- 您不能更改后台任务的 UI。为此，您必须添加 onPostExecute()。

公共类选择扩展 AsyncTask{

@Override
protected Boolean doInBackground(String... params) {

    ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
    nameValuePairs.add(new BasicNameValuePair("e_id", subString));

    try
    {
    HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://website.com/includes/select_counter.php");
        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
        HttpResponse response = httpclient.execute(httppost); 
        HttpEntity entity = response.getEntity();
        inputStream = entity.getContent();
        Log.e("pass 1", "connection success ");
}
    catch(Exception e)
{
        Log.e("Fail 1", e.toString());
        Toast.makeText(getApplicationContext(), "Invalid IP Address",
        Toast.LENGTH_LONG).show();
}     

    try
    {
        BufferedReader reader = new BufferedReader
            (new InputStreamReader(inputStream,"UTF-8"));
            StringBuilder sb = new StringBuilder();
            while ((line = reader.readLine()) != null)
    {
            sb.append(line + "\n");
        }
            inputStream.close();
            result = sb.toString();
        Log.e("pass 2", "connection success ");
}
    catch(Exception e)
    {
    Log.e("Fail 2", e.toString());
}     

try
    {
        JSONObject json_data = new JSONObject(result);
        get_yes = (json_data.getString("Vou"));
        get_no = (json_data.getString("Nao_Vou"));
        get_maybe = (json_data.getString("Talvez"));
        Log.e("pass 3", "Vou : "+ get_yes);
        Log.e("pass 4", "Não Vou : "+ get_no);
        Log.e("pass 5", "Talvez: "+ get_maybe);

    }
    catch(Exception e)
    {
        Log.e("Fail 3", e.toString());
    }

    return null;
}
@Override


protected void onPostExecute(String result) {
  setVisible(); }}