problem with a text view

I'm reading some data like speed and curent location using a single ton class....I'm reading them using an AsyncTask thread in a loop....:)....each time I'm reading a new speed and location I'm setting them in a text view above a map.

This is how a part of my code looks like:

while (true) {
    speed = ServerManager.getInstance().getLastSpeed();
    loc1 = ServerManager.getInstance().getLastLocation();
    speed = ServerManager.getInstance().getLastSpeed();
    speed_1.setText(Integer.toString(speed));
    location.setText(loc1);
}

where:

• speed-is float and
• loc1-is String.

This is how my xml looks like:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"

    >

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

 android:orientation="horizontal"

 android:layout_width="fill_parent" 
  android:id="@+id/bar"
   android:background="#FFFFFF"
 android:layout_height="wrap_content"

>

<TextView 
    android:id="@+id/prod1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="3dip" 
    android:textSize="12px"
    android:text="Current Location"
                        />
   <TextView 
    android:id="@+id/location"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="3dip" 
     android:textColor="#013220"
    android:textSize="12px"

                        />      

<TextView
 android:id="@+id/prod2"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:gravity="center_horizontal"
 android:paddingLeft="90dip"
 android:textSize="12px"
 android:text="Speed"
            />

<TextView 
    android:id="@+id/speed"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="3dip" 
    android:textColor="#013220"
    android:textSize="12px"

                        />

</LinearLayout>

<com.google.android.maps.MapView 
        android:id="@+id/mapview1"
        android:layout_width="fill_parent"
        android:layout_below="@id/bar"
        android:layout_height="wrap_content"
        android:enabled="true"
        android:clickable="true"
 android:apiKey="0egkyrbiooKAfYyj43YB6wW1cmlG-TiIILXjpBg"
/>

</RelativeLayout>

And this is the error I get posted in my logcat:

   at android.view.ViewRoot.checkThread(ViewRoot.java:2683)

 at android.view.ViewRoot.requestLayout(ViewRoot.java:557)

 at android.view.View.requestLayout(View.java:7918)

 at android.view.View.requestLayout(View.java:7918)

 at android.view.View.requestLayout(View.java:7918)

at android.view.View.requestLayout(View.java:7918)

android.widget.RelativeLayout.requestLayout(RelativeLayout.java:255)

   at android.view.View.requestLayout(View.java:7918

 at android.view.View.requestLayout(View.java:7918)

 at android.widget.TextView.checkForRelayout(TextView.java:5380)
开发者_开发问答
  at android.widget.TextView.setText(TextView.java:2684)

  at android.widget.TextView.setText(TextView.java:2552)

  at 
android.widget.TextView.setText(TextView.java:2527)

 at com.Server_1.Server4$InitTask.doInBackground(Server4.java:86)

 at com.Server_1.Server4$InitTask.doInBackground(Server4.java:1)

The line at which I get thie error is:

speed_1.setText(Integer.toString(speed));

You should always post UI updates on the UIThread.

runOnUiThread(new Runnable() {
        public void run() {
             speed_1.setText(Integer.toString(speed));
             location.setText(loc1);

        }
}

THelper is right, you cannot do any UI operations from a different thread than the main / UI one. You can either use his solution (which works great) or, since you are already using an AsyncTask you can use the methods provided by it:

• publishProgress
• onProgressUpdate

Basically, from inside your doInBackground method you call publishProgress() and the AsyncTask class handles all thread-related headaches and calls your onProgressUpdate as soon as possible, on the UI thread, ensuring that you can modify the UI (for example call setText) without any problems.