从Spinner选择更新图像

问题描述 投票:0回答:1

我被困在这一点上:

我有一个带有CardView列表的RecyclerView。

按下按钮时,addItem();调用方法,显然添加了一个项目。

这是如何做:

String text = hwtext.getText().toString();
    mList.add(new HomeWork_Item(the.image.I.want, text));
    mAdapter.notifyItemInserted(mList.size());

哪个有效,太棒了!

现在,我添加了一个Spinner。微调器包含一些主题。如果,让我们说,选择了主题历史,我想将the.image.I.wantaddItem();方法更改为drawable中的另一个方法。

我尝试使用滑行,但这不起作用:

public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
    String SpinnerText = parent.getItemAtPosition(position).toString();
    Toast.makeText(getContext(), SpinnerText, Toast.LENGTH_SHORT).show();
    if (SpinnerText.equals("History")) {

 Glide.with(getActivity()).load(R.drawable.history).into(R.id.theImageView);

    }

}

注意:仅当按下按钮调用添加方法时才会添加项目。选择一个主题后,它应该只准备在添加项目时使用的图像。

谢谢!

崩溃Logcat:

2019-03-08 14:59:10.328 9808-9808/com.reogen.ssr E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.reogen.ssr, PID: 9808
java.lang.NullPointerException: Argument must not be null
    at com.bumptech.glide.util.Preconditions.checkNotNull(Preconditions.java:31)
    at com.bumptech.glide.util.Preconditions.checkNotNull(Preconditions.java:25)
    at com.bumptech.glide.RequestBuilder.into(RequestBuilder.java:685)
    at com.reogen.ssr.Fragments.Homework.onItemSelected(Homework.java:170)
    at android.widget.AdapterView.fireOnSelected(AdapterView.java:1331)
    at android.widget.AdapterView.dispatchOnItemSelected(AdapterView.java:1320)
    at android.widget.AdapterView.-wrap1(Unknown Source:0)
    at android.widget.AdapterView$SelectionNotifier.run(AdapterView.java:1282)
    at android.os.Handler.handleCallback(Handler.java:789)
    at android.os.Handler.dispatchMessage(Handler.java:98)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6938)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)
java android arrays image updates
1个回答
0
投票

创建一个ImageView作为

ImageView historyImage = findViewById(R.id.historyImage);

然后在你的滑行中你这样做:

Glide.with(view.getContext()).load(R.drawable.history).into(historyImage);

你正在将一个int传递给into,你应该直接传递ImageView

编辑

将您的代码更改为此代码

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_homework, container, false);
insert = rootView.findViewById(R.id.insert_text);
    hwtext = rootView.findViewById(R.id.hwinput);
SubjectImage = rootView.findViewById(id.HWImage);

   spinner = rootView.findViewById(R.id.spinner);
   buildView(rootView);
        return rootView;
    }


    public void buildView(View rootView) {
    mRecyclerView = rootView.findViewById(R.id.RecycleHW);
    mRecyclerView.setHasFixedSize(true);
    mManager = new LinearLayoutManager(getActivity());
    mAdapter = new HomeWorkAdapter(mList);

    mRecyclerView.setLayoutManager(mManager);
    mRecyclerView.setAdapter(mAdapter);
}
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