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我的问题是我创建了图像数组，并且总是随机让屏幕显示这些图像中的 2 个，并且在按下 next_button 和 next 显示 2 个图像之后，但是当我转动屏幕时它会全部重置。我知道活动会改变，它必须保存“onsaveinstancestate”，但我不知道有人可以给我一个解决方案。附言。抱歉，我的代码看起来很糟糕，因为我从 kotlin 和 OOP 开始。

import android.os.Bundle
import android.view.View
import android.widget.ImageView
import androidx.appcompat.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_roll.*
import kotlinx.android.synthetic.main.activity_roll0.*
import java.lang.NullPointerException
import kotlin.random.Random

class RollActivity0 : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_roll0)

        //init array
        var cards = arrayOf(R.drawable.bart_cassidy,
                                        R.drawable.black_jack,
                                        R.drawable.calamity_janet,
                                        R.drawable.el_gringo,
                                        R.drawable.jesse_jones,
                                        R.drawable.jourdonnais,
                                        R.drawable.kit_carlson,
                                        R.drawable.lucky_duke,
                                        R.drawable.paul_regret,
                                        R.drawable.pedro_ramirez,
                                        R.drawable.rose_doolan,
                                        R.drawable.sid_ketchum,
                                        R.drawable.slab_the_killer,
                                        R.drawable.suzy_lafayette,
                                        R.drawable.vulture_sam,
                                        R.drawable.willy_the_kid)

        val random_index = java.util.Random()
        var index = 0

        //shuffling array
        for (i in cards.size - 1 downTo 1)
        {
            val j = random_index.nextInt(i + 1)
            val tmp = cards[i]
            cards[i] = cards[j]
            cards[j] = tmp
        }

        imageView3.setImageResource(cards[index])
        index++ //next image
        imageView4.setImageResource(cards[index])
        index++ //next image

        next_button1.setOnClickListener {
                if ( index >= cards.size )//if i am on end array make new shuffled array
                {
                    //shuffling array
                    for (i in cards.size - 1 downTo 1)
                    {
                        val j = random_index.nextInt(i + 1)
                        val tmp = cards[i]
                        cards[i] = cards[j]
                        cards[j] = tmp
                    }

                    index = 0 //new start
                }

                imageView3.setImageResource(cards[index])
                index++

                imageView4.setImageResource(cards[index])
                index++
        }
    }
}
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2 回答 2

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只需在活动的清单文件中添加android:configChanges="orientation|keyboardHidden" 即可。

<activity android:name=".RollActivity0"
      android:configChanges="orientation|keyboardHidden"
      android:label="@string/app_name">
于 2020-02-06T10:08:39.340 回答
0

如果我理解正确，您不希望在向右转动屏幕时这两个图像发生变化吗？这样您就可以保护当前在 onSaveInstanceState 中显示哪些图像，并在 onCreate 中读取存储的信息。

设置图片时保护您的索引

...your code...
var indexPictureOne = -1
var indexPictureTwo = -1
imageView3.setImageResource(cards[index])
indexPictureOne = index
index++ //next image
imageView4.setImageResource(cards[index])
indexPictureTwo = index
index++ //next image
...your code...

存储当前状态

override fun onSaveInstanceState(bundle: Bundle) {
   super.onSaveInstanceState(bundle);
   icicle.putInt("pictureOneIndexKey", indexPictureOne)
   icicle.putInt("pictureTwoIndexKey", indexPictureTwo)
}

再次创建活动时恢复状态

override fun onCreate(bundle: Bundle?){
   val restoredIndexPictureOne = bundle?.getInt("pictureOneIndexKey",null)
   val restoredIndexPictureTwo = bundle?.getInt("pictureTwoIndexKey",null)

   ... //if restoredIndexPictureOne and restoredIndexPictureTwo are not null 
   skip your random logic and use these indexes, else use your random logic to 
   get two new random pictures

   ...your code..
}

我希望我的问题是正确的，并且可以提供一些帮助！

于 2020-02-06T11:12:50.173 回答