android - 我在LogCat文件中找不到错误

Question

我的程序崩溃了，老实说我不知道​​。我有logcat错误，但在那儿找不到它。任何帮助将不胜感激。我收到了空指针异常，但不知道它将在哪里发生。

 package com.example.puremmacompetitionjiujitsuscorer;
//~--- non-JDK imports --------------------------------------------------------

import android.app.Activity;

import android.os.Bundle;
import android.os.CountDownTimer;

import android.view.Menu;
import android.view.View;

import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {    // Starts the main activity
private int            blueScore         = 0;
private int            redScore          = 0;
String                 flag              = "";
Button                 start             = (Button) findViewById(R.id.play);
Button                 stop              = (Button) findViewById(R.id.stop);
final ImageButton      reset             = (ImageButton) findViewById(R.id.resetButton1);
final ImageButton      blue              = (ImageButton) findViewById(R.id.imageButton9);
final ImageButton      red               = (ImageButton) findViewById(R.id.imageButton10);
final ImageButton      sweep             = (ImageButton) findViewById(R.id.imageButton5);
final ImageButton      pass              = (ImageButton) findViewById(R.id.imageButton8);
final ImageButton      mount             = (ImageButton) findViewById(R.id.imageButton4);
final ImageButton      backMount         = (ImageButton) findViewById(R.id.imageButton3);
final ImageButton      kneeOnBelly       = (ImageButton) findViewById(R.id.imageButton7);
final ImageButton      takeDown          = (ImageButton) findViewById(R.id.imageButton6);
final TextView         blueScoreCount    = (TextView) findViewById(R.id.blueScore1);
final TextView         redScoreCount     = (TextView) findViewById(R.id.redScore1);
TextView               timerOnScreen     = (TextView) findViewById(R.id.timer);
EditText               editTimerOnScreen = (EditText) findViewById(R.id.editTimer);
private CountDownTimer countDownTimer;
private long           totalTimeCountInMilliseconds;
private long           timeBlinkInMilliseconds;
private boolean        blink;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    start             = (Button) findViewById(R.id.play);
    stop              = (Button) findViewById(R.id.stop);
    timerOnScreen     = (TextView) findViewById(R.id.timer);
    editTimerOnScreen = (EditText) findViewById(R.id.editTimer);
    stop.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (v.getId() == R.id.stop) {
                timerOnScreen.setTextAppearance(getApplicationContext(), R.style.normalText);
                setTimer();
                stop.setVisibility(View.VISIBLE);
                start.setVisibility(View.GONE);
                editTimerOnScreen.setVisibility(View.GONE);
                editTimerOnScreen.setText("");
                startTimer();
            } else if (v.getId() == R.id.play) {
                countDownTimer.cancel();
                start.setVisibility(View.VISIBLE);
                stop.setVisibility(View.GONE);
                editTimerOnScreen.setVisibility(View.VISIBLE);
            }
        }
        private void setTimer() {
            int time = 0;

            if (!editTimerOnScreen.getText().toString().equals("")) {
                time = Integer.parseInt(editTimerOnScreen.getText().toString());
            } else {
                Toast.makeText(MainActivity.this, "Please Enter Minutes...", Toast.LENGTH_LONG).show();
            }

            totalTimeCountInMilliseconds = 60 * time * 1000;
            timeBlinkInMilliseconds      = 30 * 1000;
        }
        private void startTimer() {
            countDownTimer = new CountDownTimer(totalTimeCountInMilliseconds, 500) {

                // 500 means, onTick function will be called at every 500
                // milliseconds

                @Override
                public void onTick(long leftTimeInMilliseconds) {
                    int seconds = (int) (leftTimeInMilliseconds / 1000);

                    if (leftTimeInMilliseconds < timeBlinkInMilliseconds) {
                        timerOnScreen.setTextAppearance(getApplicationContext(), R.style.blinkText);

                        // change the style of the textview .. giving a red
                        // alert style
                        if (blink) {
                            timerOnScreen.setVisibility(View.VISIBLE);

                            // if blink is true, textview will be visible
                        } else {
                            timerOnScreen.setVisibility(View.INVISIBLE);
                        }

                        blink = !blink;    // toggle the value of blink
                    }

                    timerOnScreen.setText(String.format("%02d:%02d:%02d", seconds / 3600,
                            (seconds % 3600) / 60, (seconds % 60)));

                    // format the textview to show the easily readable format
                }
                @Override
                public void onFinish() {

                    // this function will be called when the timecount is finished
                    timerOnScreen.setText("Time up!");
                    timerOnScreen.setVisibility(View.VISIBLE);
                    start.setVisibility(View.VISIBLE);
                    stop.setVisibility(View.GONE);
                    editTimerOnScreen.setVisibility(View.VISIBLE);
                }
            }.start();
        }
    });
    reset.setOnClickListener(new View.OnClickListener() {    // resets the score values in the top corners back to 0
        public void onClick(View u) {
            redScore = 0;
            redScoreCount.setText("" + redScore);
            blueScore = 0;
            blueScoreCount.setText("" + blueScore);
        }
    });
    blue.setOnClickListener(new View.OnClickListener() {    // assigns the value of flag to the blueScore when the blue button is clicked
        public void onClick(View g) {
            flag = "blue";
        }
    });
    red.setOnClickListener(new View.OnClickListener() {    // assigns the value of flag to the redScore when the red button is clicked
        public void onClick(View m) {
            flag = "red";
        }
    });
    takeDown.setOnClickListener(new View.OnClickListener() {    // adds 2 points to either the blue or red score depending on which flag was hit last
        public void onClick(View v) {
            if (!flag.equals("")) {
                ;
            }

            {
                if ("red".equals(flag)) {
                    redScore += 2;
                    redScoreCount.setText("" + redScore);
                } else {
                    blueScore += 2;
                    blueScoreCount.setText("" + blueScore);
                }
            }
        }
    });
    sweep.setOnClickListener(new View.OnClickListener() {    // adds 2 points to either the blue or red score depending on which flag was hit last
        public void onClick(View w) {
            if (!flag.equals("")) {
                ;
            }

            {
                if ("red".equals(flag)) {
                    redScore += 2;
                    redScoreCount.setText("" + redScore);
                } else {
                    blueScore += 2;
                }

                blueScoreCount.setText("" + blueScore);
            }
        }
    });
    pass.setOnClickListener(new View.OnClickListener() {    // adds 3 points to either the blue or red score depending on which flag was hit last
        public void onClick(View q) {
            if (!flag.equals("")) {
                ;
            }

            {
                if ("red".equals(flag)) {
                    redScore += 3;
                    redScoreCount.setText("" + redScore);
                } else {
                    blueScore += 3;
                }

                blueScoreCount.setText("" + blueScore);
            }
        }
    });
    mount.setOnClickListener(new View.OnClickListener() {    // adds 4 points to either the blue or red score depending on which flag was hit last
        public void onClick(View t) {
            if (!flag.equals("")) {
                ;
            }

            {
                if ("red".equals(flag)) {
                    redScore += 4;
                    redScoreCount.setText("" + redScore);
                } else {
                    blueScore += 4;
                }

                blueScoreCount.setText("" + blueScore);
            }
        }
    });
    backMount.setOnClickListener(new View.OnClickListener() {    // adds 4 points to either the blue or red score depending on which flag was hit last
        public void onClick(View s) {
            if (!flag.equals("")) {
                ;
            }

            {
                if ("red".equals(flag)) {
                    redScore += 4;
                    redScoreCount.setText("" + redScore);
                } else {
                    blueScore += 4;
                }

                blueScoreCount.setText("" + blueScore);
            }
        }
    });
    kneeOnBelly.setOnClickListener(new View.OnClickListener() {    // adds 2 points to either the blue or red score depending on which flag was hit last
        public void onClick(View g) {
            if (!flag.equals("")) {
                ;
            }

            {
                if ("red".equals(flag)) {
                    redScore += 2;
                    redScoreCount.setText("" + redScore);
                } else {
                    blueScore += 2;
                }

                blueScoreCount.setText("" + blueScore);
            }
        }
    });
}

public boolean onCreateOptionsMenu(Menu menu) {    // I have no idea what this does. It's just automatically generated

    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);

    return true;
}

}

//〜由Jindent格式化--- http://www.jindent.com

Answer 1

findViewById()仅在创建 View 后才起作用，这在此处的onCreate()中发生:setContentView(R.layout.activity_main);
因此，要解决您的问题，只需将右侧具有findViewById()的所有分配移动到onCreate()行下方的setContentView(R.layout.activity_main);(如已经建议过的Raghunandan)。