特定时间段后如何显示活动

我猜您还参加了一项主要活动或家庭活动？如果是这样，您可以执行以下操作以获得所需的结果：

在您的firstactivity onCreate（）方法中：

Button mButton = (Button)findViewById(R.id.TestButton);
    final EditText mEditText = (EditText)findViewById(R.id.TestTextBox);
    mButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int time = Integer.parseInt(mEditText.getText().toString());
            Intent intent = new Intent(getApplicationContext(), MainActivity.class);
            intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            intent.putExtra("Time", time);
            startActivity(intent);
        }
    });

比在您的mainactivity的onCreate（）方法中放置以下内容：

if (getIntent().getIntExtra("Time", 0) > 0) {
        int time = getIntent().getIntExtra("Time" , 0);
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                Intent intent = new Intent(MainActivity.this, SecondActivity.class);
                startActivity(intent);
                finish();
            }
        }, time * 1000);
    }

编辑：（如果您没有MainActivity）

第一：在XML内注册接收者

<receiver android:name=".AlarmReceiver"/>

创建AlarmReceiver类

package (your package)

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

public class AlarmReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
    Toast.makeText(context, "Alarm time reached", Toast.LENGTH_SHORT).show();
    Intent i = new Intent();
    i.setClassName("(your package name)", "(your package name.SecondActivity)");
    i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    context.startActivity(i);
    }
}

在您的FirstActivity的onCreate方法中：

Button mButton = (Button)findViewById(R.id.TestButton);
    final EditText mEditText = (EditText)findViewById(R.id.TestTextBox);
    mButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int time = Integer.parseInt(mEditText.getText().toString());
            if(time > 0) {
                Intent myIntent = new Intent(getBaseContext(), AlarmReceiver.class);
                PendingIntent pendingIntent = PendingIntent.getBroadcast(getBaseContext(), 0, myIntent, 0);
                AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
                Calendar calendar = Calendar.getInstance();
                calendar.setTimeInMillis(System.currentTimeMillis());
                calendar.add(Calendar.SECOND, time);
                alarmManager.set(AlarmManager.RTC_WAKEUP,calendar.getTimeInMillis(), pendingIntent);
                Toast.makeText(getApplicationContext(), "Starting Activity in: " + time + " seconds", Toast.LENGTH_SHORT).show();
                finish();
            }
        }
    });

希望这可以帮助你 ;）

PS：关于在活动之间传递图像，您可以尝试以下操作：首先在活动顶部声明位图：

private Intent myIntent;

将以下代码添加到FirstActivity中的onCreate方法中

myIntent = new Intent(FirstActivity.this, AlarmReceiver.class);

并在下面添加以下bitmap = BitmapFactory.decodeFile(f.getAbsolutePath(), bitmapOptions);内容：

ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();
myIntent.putExtra("SendImage", byteArray);

并在下面添加 Bitmap thumbnail = (BitmapFactory.decodeFile(picturePath));

ByteArrayOutputStream stream = new ByteArrayOutputStream();
thumbnail.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();
myIntent.putExtra("SendImage", byteArray);

然后在您的AlarmReceiver中

byte[] mByteArray = intent.getByteArrayExtra("SendImage")  //above Intent i = new Intent();
i.putExtra("Image", mByteArray); //above context.startActivity(i);

并在您的SecondActivity中

byte[] mByteArray= getIntent().getByteArrayExtra("Image");
if(mByteArray != null){
    Bitmap mBitmap = BitmapFactory.decodeByteArray(mByteArray, 0, mByteArray.length);
    mTestImage.setImageBitmap(mBitmap); //Your imageview
}

不要以为这是最好的解决方案，但是我已经对此进行了测试，并且效果很好；）