我正在创建一个Pomodoro Timer应用程序。它有两个活动：
-
第一个是主页。
-
第二是设定时间。
-
我想用最近的时间做第三个活动
我想创建第三个活动，从第二个活动中获取输入时间并将其存储在列表中，但我不知道如何将输入数据从第二次活动传输到第三次活动
活动1：
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button newTime = findViewById(R.id.newTime);
Button currentTime = findViewById(R.id.currentTime);
Button recents = findViewById(R.id.recentTime);
newTime.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent activity2Intent = new Intent(getApplicationContext(), Activity2.class);
startActivity(activity2Intent);
overridePendingTransition(R.anim.slide_in_right,R.anim.slide_out_left);
}
});
// currentTime.setOnClickListener(new View.OnClickListener() {
// @Override
// public void onClick(View v) {
// Intent currentActivityIntent = new Intent(getApplicationContext(), currentActivity.class);
// startActivity(currentActivityIntent);
// overridePendingTransition(R.anim.slide_in_right,R.anim.slide_out_left);
// }
// });
}
}
活动2：
package com.example.pomotimer;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.TimePicker;
import android.widget.Toast;
import java.util.Locale;
public class Activity2 extends AppCompatActivity {
private TextView TextViewCountdown;
private Button Button_Start_Pause;
private Button Reset;
private Button buttonSet;
private Button select_Time;
private EditText edit_Text_Input;
private CountDownTimer countDownTimer;
public long mStartTimeinMillis;
private long timeLeft = mStartTimeinMillis;
private boolean timerRunning;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_2);
TextViewCountdown = findViewById(R.id.textViewCount);
Button_Start_Pause = findViewById(R.id.bnStartPause);
Reset = findViewById(R.id.reset);
select_Time = findViewById(R.id.selectTime);
edit_Text_Input = findViewById(R.id.edit_Text_Input);
buttonSet = findViewById(R.id.buttonSet);
select_Time.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit_Text_Input.setVisibility(View.VISIBLE);
buttonSet.setVisibility(View.VISIBLE);
buttonSet.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String input = edit_Text_Input.getText().toString();
if (input.length() == 0){
Toast.makeText(Activity2.this, "Field can't be empty", Toast.LENGTH_SHORT).show();
return;
}
long millisInput = Long.parseLong(input)*60000;
if (millisInput == 0){
Toast.makeText(Activity2.this, "Timer cannot be set to 0", Toast.LENGTH_SHORT).show();
return;
}
setTime(millisInput);
edit_Text_Input.setText("");
// Intent res = new Intent(getApplicationContext(), currentActivity.class);
// startActivityForResult(res, (int) millisInput, null);
}
});
}
});
Button_Start_Pause.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (timerRunning){
pauseTimer();
}
else{
startTimer();
}
}
});
Reset.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
resetTimer();
}
});
int minutes = (int) (timeLeft/1000)/60;
int seconds = (int) (timeLeft/1000)%60;
String timeLeftFormatted = String.format(Locale.getDefault(),"%02d:%02d", minutes, seconds);
TextViewCountdown.setText(timeLeftFormatted);
}
@Override
public void finish() {
super.finish();
overridePendingTransition(R.anim.slide_in_left, R.anim.slide_out_right);
}
public void setTime(long milliseconds){
mStartTimeinMillis = milliseconds;
resetTimer();
}
private void startTimer(){
countDownTimer = new CountDownTimer(timeLeft,1000) {
@Override
public void onTick(long millisUntilFinished) {
// The countdown timer has an automatic method of reducing time by 1s
timeLeft = millisUntilFinished;
int minutes = (int) (timeLeft/1000)/60;
int seconds = (int) (timeLeft/1000)%60;
String timeLeftFormatted = String.format(Locale.getDefault(),"%02d:%02d", minutes, seconds);
TextViewCountdown.setText(timeLeftFormatted);
}
@Override
public void onFinish() {
timerRunning = false;
Button_Start_Pause.setText("Start");
Button_Start_Pause.setVisibility(View.INVISIBLE);
}
}.start();
timerRunning = true;
Button_Start_Pause.setText("pause");
}
private void pauseTimer(){
countDownTimer.cancel();
timerRunning = false;
Button_Start_Pause.setText("Start");
}
private void resetTimer(){
timeLeft = mStartTimeinMillis;
int minutes = (int) (timeLeft/1000)/60;
int seconds = (int) (timeLeft/1000)%60;
Button_Start_Pause.setVisibility(View.VISIBLE);
String timeLeftFormatted = String.format(Locale.getDefault(),"%02d:%02d", minutes, seconds);
TextViewCountdown.setText(timeLeftFormatted);
}
@Override
protected void onStop() {
super.onStop();
SharedPreferences prefs = getSharedPreferences("prefs", MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
editor.putLong("millisleft", timeLeft);
editor.putBoolean("timerRunning", timerRunning);
editor.apply();
}
@Override
protected void onStart() {
super.onStart();
SharedPreferences prefs = getSharedPreferences("prefs", MODE_PRIVATE);
timeLeft = prefs.getLong("millisleft",mStartTimeinMillis);
timerRunning = prefs.getBoolean("timeRunning", false);
int minutes = (int) (timeLeft/1000)/60;
int seconds = (int) (timeLeft/1000)%60;
String timeLeftFormatted = String.format(Locale.getDefault(),"%02d:%02d", minutes, seconds);
TextViewCountdown.setText(timeLeftFormatted);
}
}
我们可以使用Intent将数据传递给另一个活动。
与启动活动之前一样，我们需要执行以下操作：intent.putExtra("数据"，Data(；
在创建的第三个活动中，我们需要intent.getStringExtra("数据"(；
Activity2内部
您可以将数据直接放置在Intent中，也可以将它们放在Bundle中，然后将放在Intent中。为了保持一致性，避免同时使用两者。
Intent activity3Intent = new Intent(getApplicationContext(), Activity3.class);
//Direct Intent approach
activity3Intent.putExtras("YOUR_STRING_KEY","YOUR_DATA");
//OR Bundle approach
Bundle bundle = new Bundle();
bundle.putString("YOUR_STRING_KEY","YOUR_DATA");
activity3Intent.putExtras(bundle);
startActivity(activity3Intent);
在Activity3类内部。
//if direct intent approach
String value = getIntent.getStringExtra("YOUR_STRING_KEY")
//If bundle approach was used.
String value = getIntent().getExtras().getString("YOUR_STRING_KEY");