皮卡索（Picasso）非法参数异常，目标不能为空。

Question

我正在使用Picasso库在我的项目中设置图片。

当我点击View的图像时，Picasso执行时会出现错误。

应用程序的Logcat

  java.lang.IllegalArgumentException: Target must not be null.
            at com.squareup.picasso.RequestCreator.into(RequestCreator.java:340)
            at com.squareup.picasso.RequestCreator.into(RequestCreator.java:326)
            at com.zafer.celaloglu.FragmentsandActivities.UnfoldableDetailsFragment.openDetails(UnfoldableDetailsFragment.java:89)
            at com.zafer.celaloglu.model.PaintingsAdapter.onClick(PaintingsAdapter.java:52)
            at android.view.View.performClick(View.java:4084)
            at android.view.View$PerformClick.run(View.java:16966)
            at android.os.Handler.handleCallback(Handler.java:615)
            at android.os.Handler.dispatchMessage(Handler.java:92)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:4745)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)

可展开的详情碎片89 =

public void openDetails(View coverView, Painting painting) {
    ImageView image = (ImageView) coverView.findViewById(R.id.details_image);
    TextView title = (TextView) coverView.findViewById(R.id.details_title);
    TextView description = (TextView) coverView.findViewById(R.id.details_text);

    Picasso.with(getActivity()).load(painting.getImageId()).into(image); ->89. LINE
    Log.i("bilgi", "basildi");

    title.setText(painting.getTitle());

    SpannableBuilder builder = new SpannableBuilder(getActivity());
    builder
            .createStyle().setFont(Typeface.DEFAULT_BOLD).apply()
            .append(R.string.year).append(": ")
            .clearStyle()
            .append(painting.getYear()).append("\n")
            .createStyle().setFont(Typeface.DEFAULT_BOLD).apply()
            .append(R.string.location).append(": ")
            .clearStyle()
            .append(painting.getLocation());
    description.setText(builder.build());

    mUnfoldableView.unfold(coverView, mDetailsLayout);
}

画笔适配器：

public class PaintingsAdapter extends ItemsAdapter<Painting> implements View.OnClickListener {

public PaintingsAdapter(Context context) {
    super(context);
    setItemsList(Arrays.asList(Painting.getAllPaintings(context.getResources())));
}

@Override
protected View createView(Painting item, int pos, ViewGroup parent, LayoutInflater inflater) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
    ViewHolder vh = new ViewHolder();
    vh.image = Views.find(view, R.id.list_item_image);
    vh.image.setOnClickListener(this);
    vh.title = Views.find(view, R.id.list_item_title);
    view.setTag(vh);

    return view;
}

@Override
protected void bindView(Painting item, int pos, View convertView) {
    ViewHolder vh = (ViewHolder) convertView.getTag();

    vh.image.setTag(item);
    Picasso.with(convertView.getContext()).load(item.getImageId()).noFade().into(vh.image);
    vh.title.setText(item.getTitle());
}

@Override
public void onClick(View view) {
    //Log.i("bilgi", "basildi");
    UnfoldableDetailsFragment fm = new UnfoldableDetailsFragment();
    fm.openDetails(view, (Painting)view.getTag()); -->HERE IS 52. line
    Log.i("bilgi", "basildi");

}

private static class ViewHolder {
    ImageView image;
    TextView title;
}

- Zafer Celaloglu

---

你能解决这个问题吗？有些建议可以帮助你吗？因为我也遇到了同样的问题。 - Manuel Lucas

Answer 1

image 是传递给 into 的目标。它就是那个 null。

确保您的布局ID对于所有配置都是正确的，并指定 @+id/details_image。

- Jake Wharton

---

是的，图像返回空值，但所有配置都是正确的。 - Zafer Celaloglu

Answer 2

确保你膨胀（inflate）的是正确的 XML。这是我的问题，因为我复制了一个已经存在的适配器，忘记改变它了。

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View v = LayoutInflater.from(context)
            .inflate(R.layout.list_item_subcategories, parent, false);

我应该放置的布局是list_item_categories。

- Jaad Chacra

Answer 3

我知道这有点老了，但是我刚刚花了很多时间才发现忘记运行“setContentView”到图像所在的布局上。

ImageView在它所在的主要布局被充气之前将为空;)

- Dwebtron

Answer 4

请确认您的ImageView对象的ID是否正确 -

imageView=itemView.findViewById(R.id.imageview1);

- Raj Godara

Answer 5

@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(context).inflate(R.layout.show_item, parent, false);
    return new ViewHolder(view);
}

确保选择正确的布局资源文件，这就是导致我出错的原因。

- Tsogang Mosweswe

Answer 6

或者是 painting.getImageId() 为空或为 null？

还是 image 或 getActivity() 有问题？:)

- Serhii Nadolynskyi

---

最初的实现是在Activity上，我将其转换为Fragment，因此我在Adapter的onClick方法上进行了一些更改： @Override public void onClick(View view) { if (view.getContext() instanceof UnfoldableDetailsActivity) { UnfoldableDetailsActivity activity = (UnfoldableDetailsActivity) view.getContext(); activity.openDetails(view, (Painting) view.getTag()); } } - Zafer Celaloglu

Answer 7

请检查您在布局文件中设置的Id。

android:id="@+id/details_image"

那么，

 ImageView image = (ImageView) coverView.findViewById(R.id.details_image);

- Kamrujjaman Joy