“动画师只能在活套线程上运行”错误时，从资产文件夹(Android)将图像加载到ImageView

Question

我正在尝试构建一些方法，允许我使用图像的名称一次从本地文件夹加载一个.png图像。我选择从assets文件夹加载，因为res文件夹没有按图像名加载。在阅读了相当多的问答之后，我提出了以下方法：

    private void setImage(String imageName) {
        String imageReference = String.format("%1$s/%2$s", "images", imageName);
        Context appContext = getContext().getApplicationContext();
        AssetManager assetManager = appContext.getAssets();
        // get input stream
        InputStream inputStream = null;
        try {
            inputStream = assetManager.open(imageReference);
        } catch (IOException e) {
            e.printStackTrace();
        }
        // load image as drawable
        Drawable drawable = null;
        drawable = Drawable.createFromStream(inputStream, null);
        // set image to ImageView
        imageView.setImageDrawable(drawable);
        try {
            inputStream .close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

...where“图像”是资产文件夹中的子目录。使用调试器，我可以看到该方法正在成功地获取图像，但一旦它到达代码imageView.setImageDrawable(drawable);行，模拟器就会抛出以下错误：AndroidRuntimeException: Animators may only be run on Looper threads

就我的用法而言，我曾试图找出这意味着什么，但到目前为止我还是失败了。感激地收到任何帮助/建议:)

编辑：这是我最新的堆栈跟踪，自从我发布问题后(很可能)发生了轻微的变化：

E/AndroidRuntime: FATAL EXCEPTION: Timer-3
    Process: com.example.spineapp.debug, PID: 10369
    android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
        at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:7753)
        at android.view.ViewRootImpl.requestLayout(ViewRootImpl.java:1225)
        at android.view.View.requestLayout(View.java:23093)
        at android.view.View.requestLayout(View.java:23093)
        at android.view.View.requestLayout(View.java:23093)
        at android.view.View.requestLayout(View.java:23093)
        at android.view.View.requestLayout(View.java:23093)
        at android.view.View.requestLayout(View.java:23093)
        at android.view.View.requestLayout(View.java:23093)
        at android.view.View.requestLayout(View.java:23093)
        at android.view.View.requestLayout(View.java:23093)
        at android.widget.ScrollView.requestLayout(ScrollView.java:1533)
        at android.view.View.requestLayout(View.java:23093)
        at android.view.View.requestLayout(View.java:23093)
        at android.view.View.requestLayout(View.java:23093)
        at android.widget.ImageView.setImageDrawable(ImageView.java:571)
        at android.support.v7.widget.AppCompatImageView.setImageDrawable(AppCompatImageView.java:100)
        at com.spineapp.LeftRightJudgementStepLayout.setImage(LeftRightJudgementStepLayout.java:583)
        at com.spineapp.LeftRightJudgementStepLayout.startQuestion(LeftRightJudgementStepLayout.java:521)
        at com.spineapp.LeftRightJudgementStepLayout.startNextQuestionOrFinish(LeftRightJudgementStepLayout.java:1031)
        at com.spineapp.LeftRightJudgementStepLayout$7.run(LeftRightJudgementStepLayout.java:482)
        at java.util.TimerThread.mainLoop(Timer.java:562)
        at java.util.TimerThread.run(Timer.java:512)

Answer 1

您可能是从一个非UI线程调用setImageDrawable()。

尝试在UI线程上调度setImageDrawable。

imageView.post(
// or inside an activity use
// runOnUiThread(
  new Runnable() {
    @Override
    public void run() {
      imageView.setImageDrawable(...);
    }
  }
);

https://developer.android.com/reference/android/view/View#post(java.lang.Runnable)

https://developer.android.com/reference/android/app/Activity#runOnUiThread(java.lang.Runnable)