Apps IllegalStateException: cannot find method...

[ac4android]

I am trying to implement a stop-watch on Android.
I can build the "gradle" based on Nexus4 API21, but when I click on the "Start" button, I keep getting this error, which doesn't make much sense to me.

01-05 14:37:17.961 1131-1131/com.hfad.stopwatch E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.hfad.stopwatch, PID: 1131
java.lang.IllegalStateException: Could not find a method onClickStart(View) in the activity class com.hfad.stopwatch.StopwatchActivity for onClick handler on view class android.widget.Button with id 'start_button'
...

Here is the "content_stopwatch.xml", invoked by "activity_stopwatch.xml", as you can see I have the "@+id/start_button"
<TextView
android:id="@+id/time_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="0dp"
android:text=""
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="92sp" />

<Button
android:id="@+id/start_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/time_view"
android:layout_centerHorizontal="true"
android:layout_marginTop="20dp"
androidnClick="onClickStart"
android:text="@String/start" />

The values in string.xml
<resources>
<string name="app_name">Stopwatch</string>
<string name="action_settings">Settings</string>
<string name="start">Start</string>
<string name="stop">Stop</string>
<string name="reset">Reset</string>
</resources>

Here is the Java code snippet :

import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.app.Activity;
import android.widget.TextView;

public class StopwatchActivity extends Activity {

    // number of seconds displayed on the stopwatch.
    private int seconds = 0;
    // is stop watch running?
    private boolean running;
    private boolean wasRunning;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_stopwatch);
        if (savedInstanceState != null) {
            seconds = savedInstanceState.getInt("seconds");
            running = savedInstanceState.getBoolean("running");
            wasRunning = savedInstanceState.getBoolean("wasRunning");
        }
        runTimer();
    }
  // many lines elided...
    @Override
    protected void onSaveInstanceState(Bundle savedInstanceState){
        savedInstanceState.putInt("seconds", seconds);
        savedInstanceState.putBoolean("running", running);
        savedInstanceState.putBoolean("wasRunning", wasRunning);
    }
        // start the stopwatch running when the Start button is clicked.
    protected void onClickStart(View view){
        running = true;
    }

Can anyone see what I have missed?

 

[Deleted User]

Try making the onClickStart() method public instead of protected

 

[ac4android]

Try making the onClickStart() method public instead of protected

Thanks, that solved the problem.

Of course they have to be public, the buttons were U.I. for public