如何在应用程序（活动）仍在运行时刷新它？

Question

我刚刚制作了一个应用程序，询问另外一个问题。我想刷新整个应用程序，我该怎么做？我需要知道的是如何刷新它 - 问题，我可以自己弄清楚。

我的目标只是让屏幕返回到开始屏幕，而不是应用程序自行关闭然后重新启动。（如果这是唯一的方法，那就是它可用）

的java：

package com.example.android.mathapp;

import android.content.pm.ActivityInfo;
import android.graphics.drawable.AnimationDrawable;
import android.media.Image;
import android.os.Build;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.TranslateAnimation;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.Random;

public class MainActivity extends AppCompatActivity{
private boolean correct;
private String questionTxt, option1String, option2String, option3String, option4String;
private int answer;
TextView option1Text, option2Text, option3Text, option4Text;
private String[] ansString = new String[4];
private int counter = 0;
float f = 100;

public void correctAnswer()
{
    int first = (int)(Math.random() * 10);
    int second = (int)(Math.random() * 10);
    answer = first + second;
    questionTxt = first + " + " + second + " = ?";
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_NOSENSOR);

    /*ImageView rocketImage = (ImageView) findViewById(R.id.img_animation);
    rocketImage.setBackgroundResource(R.drawable.greencartooncar);
    rocketAnimation = (AnimationDrawable) rocketImage.getBackground();*/

    TextView questionText = (TextView)findViewById(R.id.question);
    correctAnswer();
    questionText.setText(questionTxt + "");
    TextView directionsEnd = (TextView)findViewById(R.id.directions);
    directionsEnd.setText("Get 10 questions right to finish the race!");
    makeOptions(answer);
    option1Text = (TextView)findViewById(R.id.option1);
    option1Text.setText(ansString[0]);
    option2Text = (TextView)findViewById(R.id.option2);
    option2Text.setText(ansString[1]);
    option3Text = (TextView)findViewById(R.id.option3);
    option3Text.setText(ansString[2]);
    option4Text = (TextView)findViewById(R.id.option4);
    option4Text.setText(ansString[3]);
    setString();
    //noSameAnswer();
}

private String[] makeOptions(int correctAns) {

    for(int i=0;i<ansString.length;i++)
    {
        ansString[i] = null;
    }

    int randomPos = (new Random().nextInt(4 - 1) + 1);
    ansString[randomPos]=correctAns + "";

    for (int i=0;i<4;i++){
        int randomAns = (int)(Math.random() * 10 + Math.random() * 10);
        if(ansString[i] == null){
            ansString[i]=randomAns + "";
        }
    }

    if (ansString[0].equals(ansString[1])||ansString[0].equals(ansString[2])||ansString[0].equals(ansString[3])
            ||ansString[1].equals(ansString[2]) ||ansString[1].equals(ansString[3])||ansString[2].equals(ansString[3]))
    {
        makeOptions(answer);
    }

    return ansString;
}

/*public void noSameAnswer()
{
    if (option1String.equals(option2String)||option1String.equals(option3String)||option1String.equals(option4String)
            ||option2String.equals(option3String)||option2String.equals(option4String)||option3String.equals(option4String))
    {
        makeOptions(answer);
        option1Text = (TextView)findViewById(R.id.option1);
        option1Text.setText(ansString[0]);
        option2Text = (TextView)findViewById(R.id.option2);
        option2Text.setText(ansString[1]);
        option3Text = (TextView)findViewById(R.id.option3);
        option3Text.setText(ansString[2]);
        option4Text = (TextView)findViewById(R.id.option4);
        option4Text.setText(ansString[3]);
        setString();
        noSameAnswer();
    }
}*/

public void onClick3(View v) {
    if (option3String.equals(Integer.toString(answer))) {
        counter++;
        TextView questionText = (TextView) findViewById(R.id.question);
        correctAnswer();
        questionText.setText(questionTxt + "");
        makeOptions(answer);
        option1Text = (TextView)findViewById(R.id.option1);
        option1Text.setText(ansString[0]);
        option2Text = (TextView)findViewById(R.id.option2);
        option2Text.setText(ansString[1]);
        option3Text = (TextView)findViewById(R.id.option3);
        option3Text.setText(ansString[2]);
        option4Text = (TextView)findViewById(R.id.option4);
        option4Text.setText(ansString[3]);
        setString();
        animate();
        //noSameAnswer();
    }
}

public void onClick1(View v) {
    if (option1String.equals(Integer.toString(answer))) {
        counter++;
        TextView questionText = (TextView) findViewById(R.id.question);
        correctAnswer();
        questionText.setText(questionTxt + "");
        makeOptions(answer);
        option1Text = (TextView)findViewById(R.id.option1);
        option1Text.setText(ansString[0]);
        option2Text = (TextView)findViewById(R.id.option2);
        option2Text.setText(ansString[1]);
        option3Text = (TextView)findViewById(R.id.option3);
        option3Text.setText(ansString[2]);
        option4Text = (TextView)findViewById(R.id.option4);
        option4Text.setText(ansString[3]);
        setString();
        animate();
        //noSameAnswer();
    }
}

public void onClick2(View v) {
    if (option2String.equals(Integer.toString(answer))) {
        counter++;
        TextView questionText = (TextView) findViewById(R.id.question);
        correctAnswer();
        questionText.setText(questionTxt + "");
        makeOptions(answer);
        option1Text = (TextView)findViewById(R.id.option1);
        option1Text.setText(ansString[0]);
        option2Text = (TextView)findViewById(R.id.option2);
        option2Text.setText(ansString[1]);
        option3Text = (TextView)findViewById(R.id.option3);
        option3Text.setText(ansString[2]);
        option4Text = (TextView)findViewById(R.id.option4);
        option4Text.setText(ansString[3]);
        setString();
        animate();
        //noSameAnswer();
    }
}

public void onClick4(View v) {
    if (option4String.equals(Integer.toString(answer))) {
        counter++;
        TextView questionText = (TextView) findViewById(R.id.question);
        correctAnswer();
        questionText.setText(questionTxt + "");
        makeOptions(answer);
        option1Text = (TextView)findViewById(R.id.option1);
        option1Text.setText(ansString[0]);
        option2Text = (TextView)findViewById(R.id.option2);
        option2Text.setText(ansString[1]);
        option3Text = (TextView)findViewById(R.id.option3);
        option3Text.setText(ansString[2]);
        option4Text = (TextView)findViewById(R.id.option4);
        option4Text.setText(ansString[3]);
        setString();
        animate();
        //noSameAnswer();
    }
}

public void setString()
{
    option1String = option1Text.getText().toString();
    option2String = option2Text.getText().toString();
    option3String = option3Text.getText().toString();
    option4String = option4Text.getText().toString();
}

public void animate()
{
    ImageView img_animation = (ImageView) findViewById(R.id.car);

    TranslateAnimation animation = new TranslateAnimation(f - 100, f,
            0.0f, 0.0f);
    animation.setDuration(1000);
    animation.setFillAfter(true);
    img_animation.startAnimation(animation);
    f += 100;
}
}

的xml：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:screenOrientation="portrait"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/bigboi"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.android.mathapp.MainActivity">

                                     - ＆GT;

<TextView
    android:id="@+id/option3"
    android:layout_width="175dp"
    android:layout_height="120dp"
    android:background = "@drawable/rounded_corner"
    android:layout_alignParentBottom="true"
    android:layout_alignParentLeft="true"
    android:textAppearance="?android:textAppearanceLarge"
    android:gravity="center"
    android:layout_marginTop="5dp"
    android:layout_marginRight="5dp"
    android:screenOrientation="portrait"
    android:onClick="onClick3"
    android:clickable="true"
    android:text="option 3" />

<TextView
    android:id="@+id/option1"
    android:text="option 1"
    android:layout_width="175dp"
    android:layout_height="120dp"
    android:background = "@drawable/rounded_corner"
    android:textAppearance="?android:textAppearanceLarge"
    android:gravity="center"
    android:screenOrientation="portrait"
    android:layout_above="@+id/option3"
    android:onClick="onClick1"
    android:clickable="true"/>

<TextView
    android:id="@+id/option2"
    android:layout_width="175dp"
    android:layout_height="120dp"
    android:background = "@drawable/rounded_corner"
    android:textAppearance="?android:textAppearanceLarge"
    android:gravity="center"
    android:text="option 2"
    android:screenOrientation="portrait"
    android:layout_above="@+id/option3"
    android:layout_toRightOf="@+id/option3"
    android:onClick="onClick2"
    android:clickable="true"/>

<ImageView
    android:id="@+id/car"
    android:layout_width="60dp"
    android:layout_height="30dp"
    android:src="@drawable/greencartooncar"
    android:layout_alignParentTop="true" />

<TextView
    android:id="@+id/option4"
    android:layout_width="175dp"
    android:layout_height="120dp"
    android:background = "@drawable/rounded_corner"
    android:textAppearance="?android:textAppearanceLarge"
    android:gravity="center"
    android:text="option 4"
    android:layout_alignParentBottom="true"
    android:layout_toRightOf="@+id/option3"
    android:layout_toEndOf="@+id/option3"
    android:screenOrientation="portrait"
    android:onClick="onClick4"
    android:clickable="true"/>

<TextView
    android:id="@+id/question"
    android:background="@color/colorAccent"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:gravity="center"
    android:layout_above="@+id/option1"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_marginBottom="11dp"
    android:textSize="30sp"
    android:screenOrientation="portrait"/>
<TextView
    android:id="@+id/directions"
    android:layout_width="match_parent"
    android:layout_height="60dp"
    android:gravity="center"
    android:layout_above="@id/question"
    android:textSize="15sp"/>
<ImageView
    android:id="@+id/finish"
    android:layout_width="50dp"
    android:layout_height="75dp"
    android:layout_alignParentTop="true"
    android:layout_alignParentRight="true"
    android:src="@drawable/finish"/>
<TextView
    android:layout_width="20dp"
    android:layout_height="10dp"
    android:layout_above="@+id/directions"
    android:layout_alignParentRight="true"
    android:text="FINISH"
    android:layout_below="@+id/finish"
    android:layout_alignLeft="@+id/finish"
    android:layout_alignStart="@+id/finish" />

Answer 1

您可以使用此代码

        Intent mStartActivity = new Intent(YourCurrActivity.this, ClassYouNeedToReLaunch.class);
        int mPendingIntentId = 123456;
        PendingIntent mPendingIntent = PendingIntent.getActivity(YourCurrActivity.this, mPendingIntentId,    mStartActivity, PendingIntent.FLAG_CANCEL_CURRENT);
        AlarmManager am = (AlarmManager)YourCurrActivity.this.getSystemService(Context.ALARM_SERVICE);
        am.set(AlarmManager.RTC, System.currentTimeMillis() + 100, mPendingIntent);

如果要在不同的活动中调用它，请创建静态方法

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;


public class Util {

    static void reStartActivity(Context currant, Class needToLoad ){
        Intent mStartActivity = new Intent(currant,needToLoad);
        int mPendingIntentId = 123456;
        PendingIntent mPendingIntent = PendingIntent.getActivity(currant, mPendingIntentId,mStartActivity, PendingIntent.FLAG_CANCEL_CURRENT);
        AlarmManager mgr = (AlarmManager)currant.getSystemService(Context.ALARM_SERVICE);
        mgr.set(AlarmManager.RTC, System.currentTimeMillis() + 100, mPendingIntent);
    }
}

并在任何课程Util.reStartActivity(YourCurrActivity.this,ClassYouNeedToReLaunch.class);

中调用它

可能是你的问题。

或

如果您有splashActivity或某些similler，请使用普通Intent再次调用该活动。