Question

我无法找到一个简单的解决方案来避免我的ImageSwitcher更改旋转屏幕时显示的ImageResource。我尝试在onSaveInstanceState（）和onRestoreInstanceState（）中编写不同的东西，但我找不到任何有用的东西。

我怎样才能实现这样的目标（纯伪代码）：

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {

    // Save UI state changes to the savedInstanceState.
    // This bundle will be passed to onCreate if the process is
    // killed and restarted.
    int picNum = imageSwitcher.getImageResource();

    savedInstanceState.putInt("picNum", picNum);
    // etc.

    super.onSaveInstanceState(savedInstanceState);
}

@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {

    super.onRestoreInstanceState(savedInstanceState);

    // Restore UI state from the savedInstanceState.
    // This bundle has also been passed to onCreate.
    Int picNum =  savedInstanceState.getString("picNum");
    imageSwitcher.setImageResource(picNum);
}

我不确切知道所显示的图像名称，所以每次都必须找到它（每次ImageSwitcher都会显示“raw”文件夹中的随机图像）。我正在使用的代码的简化版本是：

rawClass = R.raw.class;

fields = rawClass.getFields();

rand = new Random();

rndInt = rand.nextInt(fields.length);

resID = fields[rndInt].getInt(rawClass);

imageSwitcher.setImageResource(resID);

提前谢谢

Answer 1

我找到了解决方法：

我将resId存储在int []中，我可以将其称为switcherImageView.setImageResource(imgArr[currentPhoto]);

之后我也可以在saveonSaveInstanceState（）方法中使用它：

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {

    // Save UI state changes to the savedInstanceState.
    int randInteger = rndInt;
    int[] saveArray = imgArr;
    int picNum = imgArr[currentPhoto];

    savedInstanceState.putInt("picNum", picNum);
    savedInstanceState.putInt("randInteger", randInteger);
    savedInstanceState.putIntArray("picArr", saveArray);
    // etc.

    super.onSaveInstanceState(savedInstanceState);
}

@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {

    super.onRestoreInstanceState(savedInstanceState);

    // Restore UI state from the savedInstanceState.
    // This bundle has also been passed to onCreate.
    int[] picArr =  savedInstanceState.getIntArray("picArr");
    int picNum =  savedInstanceState.getInt("picNum");
    imgArr = picArr;
    imageSwitcher.setImageResource(picNum);
}

现在，当我旋转屏幕时，一切都很好，我可以在ImageSlider中使用相同的图片的但当我再次点击时，它与索引的关系并不重要，它将从数组imgArr[0]的最开头开始。

修改找到最终解决方案！ :)我必须明确地存储索引：doh！：

所以我写道： onSaveInstanceState（）方法中的int currentPhoto= indexNumber; savedInstanceState.putInt("currentPhoto", currentPhoto); 和

int photoCurrent = savedInstanceState.getInt("currentPhoto");

在OnRestoreIntanceState（）方法中。

现在一切正常！

Answer 2

您还可以在清单文件中添加以下行。

        android:configChanges="keyboardHidden|orientation|screenSize"/>

如何在旋转屏幕时从ImageSwitcher保存ImageResource

2 个答案: