的Android，JAVA - 無法從的AsyncTask

Question

這裏更新變量是代碼

變量聲明

public String gpu2dcurent = "1234567"; 

的AsyncTask完之後應該更新變量gpu2dcurent，但它不

private class readgpu2d extends AsyncTask<String, Void, String> { 


    protected String doInBackground(String... args) { 
     Log.i("MyApp", "Background thread starting"); 

     String aBuffer = ""; 

     try { 

      File myFile = new File("/sys/devices/platform/kgsl-2d0.0/kgsl/kgsl-2d0/gpuclk"); 
      FileInputStream fIn = new FileInputStream(myFile); 
      BufferedReader myReader = new BufferedReader(
        new InputStreamReader(fIn)); 
      String aDataRow = ""; 
      //String aBuffer = ""; 
      while ((aDataRow = myReader.readLine()) != null) { 
       aBuffer += aDataRow + "\n"; 
      } 

      ; 
      myReader.close(); 

     } catch (Exception e) { 
      Toast.makeText(getBaseContext(), e.getMessage(), 
        Toast.LENGTH_SHORT).show(); 

     } 

     return aBuffer.trim(); 
    } 

    protected void onPostExecute(String result) { 
     // Pass the result data back to the main activity 
     gpu2dcurent = result; 
     //Toast.makeText(getBaseContext(), result, 
       //Toast.LENGTH_SHORT).show(); 
     gpu.this.data = result; 

     if (gpu.this.pd != null) { 
      //gpu.this.pd.dismiss(); 
     } 
    } 

    } 

測試以查看變量是否具有新值。它沒有，它顯示1234567

TextView tx = (TextView)findViewById(R.id.textView3); 
tx.setText(gpu2dcurent); 

我錯過了什麼？當我更新的TextView從onPostExecute方法裏面工作正常，但當的AsyncTask完成變量值重置爲默認

public class gpu extends Activity{ 

public String gpu2dcurent = "1234567"; 

Answer 1

我中有你正在嘗試你的AsyncTask完成之前設定的TextView文本疑問。

是，要麼做到最好的，static public String gpu2dcurent = "1234567";

或者，在TextView設置文本onPostExecute()

protected void onPostExecute(String result) { 
     // Pass the result data back to the main activity 
     gpu2dcurent = result; 
     //Toast.makeText(getBaseContext(), result, 
       //Toast.LENGTH_SHORT).show(); 
     gpu.this.data = result; 
     if (gpu.this.pd != null) { 
      //gpu.this.pd.dismiss(); 
     } 
     tx.setText(gpu2dcurent); 
    } 
    } 

更新：

更新你的代碼有問題後，

改變這一行，

new readgpu2d().execute("blablabla"); 

到

new readgpu2d().execute("blablabla").get(); 

Answer 2

在GPU類中聲明它跟隨着：

public String gpu2dcurent = "1234567"; 

在的AsyncTask類readgpu2d，用它作爲以下：

gpu.gpu2dcurent = result; 

---

更新您的UI =用戶接口裝置的TextView在

onProgressUpdate（）的AsyncTask的

方法。

And check where have you declared gpu2dcurent variable??? 

Answer 3

儘量把的setText到onPostExecute

protected void onPostExecute(String result) { 
    TextView tx = (TextView)findViewById(R.id.textView3); 
    tx.setText(result); 

    // Pass the result data back to the main activity 
    gpu2dcurent = result; 
    //Toast.makeText(getBaseContext(), result, 
    //Toast.LENGTH_SHORT).show(); 
    gpu.this.data = result; 

    if (gpu.this.pd != null) { 
     //gpu.this.pd.dismiss(); 
    } 
} 

Answer 4

這裏是整個代碼

package rs.pedjaapps.DualCore; 

import java.io.BufferedReader; 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.IOException; 
import java.io.InputStreamReader; 
import java.util.List; 
import java.util.concurrent.TimeoutException; 
import android.app.Activity; 
import android.app.ProgressDialog; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.Spinner; 
import android.widget.AdapterView.OnItemSelectedListener; 
import android.widget.TextView; 
import android.widget.Toast; 

import com.stericson.RootTools.RootTools; 
import com.stericson.RootTools.RootToolsException; 

public class gpu extends Activity{ 

public String gpu2dcurent = "1234567"; 

private ProgressDialog pd = null; 
private Object data = null; 

private class readgpu2d extends AsyncTask<String, Void, String> { 


    protected String doInBackground(String... args) { 
     Log.i("MyApp", "Background thread starting"); 

     String aBuffer = ""; 

     try { 

      File myFile = new File("/sys/devices/platform/kgsl-2d0.0/kgsl/kgsl-2d0/gpuclk"); 
      FileInputStream fIn = new FileInputStream(myFile); 
      BufferedReader myReader = new BufferedReader(
        new InputStreamReader(fIn)); 
      String aDataRow = ""; 
      //String aBuffer = ""; 
      while ((aDataRow = myReader.readLine()) != null) { 
       aBuffer += aDataRow + "\n"; 
      } 

      //gpu2dcurent = aBuffer.trim(); 
      myReader.close(); 




     } catch (Exception e) { 
      Toast.makeText(getBaseContext(), e.getMessage(), 
        Toast.LENGTH_SHORT).show(); 

     } 




     return aBuffer.trim(); 
    } 

    protected void onPostExecute(String result) { 
     // Pass the result data back to the main activity 
     gpu2dcurent = result; 
     //Toast.makeText(getBaseContext(), result, 
       //Toast.LENGTH_SHORT).show(); 
     gpu.this.data = result; 

     if (gpu.this.pd != null) { 
      gpu.this.pd.dismiss(); 
     } 

    } 

    } 




    @Override 
public void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
setContentView(R.layout.gpu); 
this.pd = ProgressDialog.show(this, "Working..", "Loading...", true, false); 
new readgpu2d().execute("blablabla"); 
TextView tx = (TextView)findViewById(R.id.textView3); 
tx.setText(gpu2dcurent); 
} 


}