package com.example.prototypeb.ui.game.Game_components;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import com.example.prototypeb.R;
import com.example.prototypeb.ui.game.GameFragment;
public class Game_adverbs extends AppCompatActivity {
TextView timer;
CountDownTimer countdown;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.game_adverbs);
setTitle("Adverbs");
countdown.start();
Button backbutton = findViewById(R.id.backbtn1);
backbutton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent intent = new Intent(v.getContext(), GameFragment.class);
startActivity(intent);
}
});
timer = findViewById(R.id.text_view_timer);
countdown = new CountDownTimer(10000, 1000) {
public void onTick(long millisUntilFinished) {
timer.setText((int) (millisUntilFinished/1000));
}
public void onFinish() {
timer.setText("TIME'S UP!");
}
};
}
}
这是我的活动代码的一部分。我实际上希望我的计时器在我的活动开始时立即启动。 我的活动一开始,我的应用就会立即崩溃,我已经测试并确定问题出在 CountDownTimer 代码内/周围
答案 0 :(得分:1)
出现异常是因为您在初始化 countdown.start()
对象之前调用了 countdown
。
因此在初始化 countdown.start();
后或在 countdown
方法的底部移动 onCreate
可能会起作用。
这样的东西...
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.game_adverbs);
setTitle("Adverbs");
Button backbutton = findViewById(R.id.backbtn1);
backbutton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent intent = new Intent(v.getContext(), GameFragment.class);
startActivity(intent);
}
});
timer = findViewById(R.id.text_view_timer);
countdown = new CountDownTimer(10000, 1000) {
public void onTick(long millisUntilFinished) {
timer.setText((int) (millisUntilFinished/1000));
}
public void onFinish() {
timer.setText("TIME'S UP!");
}
};
countdown.start();
}
答案 1 :(得分:1)
您在定义 countdown.start();
对象之前调用了 countdown