为什么我的吐司不起作用？

Question

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.item_listview);

    myspinner = (Spinner)findViewById(R.id.spinnertype);
    String provider = myspinner.getSelectedItem().toString();

    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, type_arrays,R.layout.support_simple_spinner_dropdown_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    myspinner.setAdapter(adapter);

    myspinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
            Toast.makeText(parent.getContext(), "OnItemSelectedListener :" + parent.getItemAtPosition(pos).toString(), Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {
        }
    });

}
 }

我尝试了不同种类的吐司，但仍然没有出现。什么地方出了错？我查看了一些帖子，上面说我不能对微调器使用 onclicklistener

Answer 1

你试过了吗，这可能对你有帮助

Toast.makeText(getApplicationContext(), "OnItemSelectedListener :" + parent.getItemAtPosition(pos).toString(), Toast.LENGTH_SHORT).show();

或

Toast.makeText(YourActivity.this, "OnItemSelectedListener :" + parent.getItemAtPosition(pos).toString(), Toast.LENGTH_SHORT).show();

Answer 2

尝试使用 getContext() 而不是 getApplicationContext。

Answer 3

好的，我们再检查一下代码；

正如我所说，您需要使用当前 Activity Context。

For example, My Activity name is, MainActivity so, Use: MainActivity.this This should be the context of that Activity.But i think if you use your own code(parent.getContext()) inside the another activity, It won't show up because it's somewhere else actually you know

此外，我猜你在这里做错了（类似的东西：ArrayAdapter.createFromResource issue）

我只是引用答案：

Query the data, put it in a List or Array and use this constructor of ArrayAdapter:

ArrayAdapter<CharSequence> dataAdapter1 =  new ArrayAdapter(this, 
                                    android.R.layout.simple_spinner_item, yourArrayOrList);

更新：所以这里是：

Spinner myspinner = (Spinner)findViewById(R.id.spinnertype);
        String provider = myspinner.getSelectedItem().toString();

        ArrayAdapter<CharSequence> adapter =
                new ArrayAdapter<CharSequence>(this, type_arrays, R.layout.support_simple_spinner_dropdown_item);
                /*ArrayAdapter.createFromResource(this, type_arrays,R.layout.support_simple_spinner_dropdown_item);*/

        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        myspinner.setAdapter(adapter);

        myspinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
                Toast.makeText(MainActivity.this, "OnItemSelectedListener :" + parent.getItemAtPosition(pos).toString(), Toast.LENGTH_SHORT).show();

            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });

现在应该可以了！

为什么我的吐司不起作用？

Why didn't my toast work?

android

android-toast