多个微调器 android 相互依赖

Question

我有 3 个微调器，第一个微调器是 txt_kategori；第二 txt_kondisi ; 第三 txt_penanganan ;第二个取决于第一个，第三个取决于第二个输入，这是我的代码

txt_kategori.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) { 
            ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<>(view.getContext(), android.R.layout.simple_spinner_item, condition[position]);
            spinnerArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); // The drop down view
            txt_kondisi.setAdapter(spinnerArrayAdapter);

        }
        @Override
        public void onNothingSelected(AdapterView<?> parent) {
        }
    });
    txt_kondisi.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) { 
            ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<>(view.getContext(), android.R.layout.simple_spinner_item, handling[position]);
            spinnerArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); // The drop down view
            txt_penanganan.setAdapter(spinnerArrayAdapter);
        }
        @Override
        public void onNothingSelected(AdapterView<?> parent) {
        }
    });

问题是java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.view.View.getContext()' on a null object reference

在 ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<>(view.getContext(), android.R.layout.simple_spinner_item, handling[position]);

Answer 1

使用ActivityName.this代替view.getContext()

  ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<>(view.getContext(), android.R.layout.simple_spinner_item, condition[position]);

改为

  ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<>(ActivityName.this, android.R.layout.simple_spinner_item, condition[position]);

多个微调器 android 相互依赖

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