Java mStartTime无法解析为变量

我编写了以下代码：

package com.shadow.handler;

import android.R;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class ServiceClick extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list_item);
    }
    private Runnable mUpdateTimeTask = new Runnable() {
           public void run() {
               final long start = mStartTime;
               long millis = SystemClock.uptimeMillis() - start;
               int seconds = (int) (millis / 1000);
               int minutes = seconds / 60;
               seconds     = seconds % 60;

               if (seconds < 10) {
                   mTimeLabel.setText("" + minutes + ":0" + seconds);
               } else {
                   mTimeLabel.setText("" + minutes + ":" + seconds);            
               }

               mHandler.postAtTime(this,
                       start + (((minutes * 60) + seconds + 1) * 1000));
           }
        };

    public void startClicked(View view) {
        if (mStartTime == 0L) {
            mStartTime = System.currentTimeMillis();
            mHandler.removeCallbacks(mUpdateTimeTask);
            mHandler.postDelayed(mUpdateTimeTask, 100);
    }

    public void stopClicked(View view) {
        mHandler.removeCallbacks(mUpdateTimeTask);
    }

}

---

但是我已经声明了mStartTime和mHandler。

您还没有声明这些变量。你需要申报

Handler mHandler;
long mStartTime;
@Override
public void onCreate(Bundle savedInstanceState) {

您还需要删除

import android.R;

应该是

import com.shadow.handler.R;

---

另外，我看不到您在哪里初始化了

mHandler

mStartTime或mHandler的声明在哪里

import com.shadow.handler.R;