从不同 class 编辑 TextView 时强制关闭

force close when editing TextView from different class

我想使用 Class B[= 中微调器的数据编辑 Class A 中的 TextView 14=]

Class一个

TextView tvv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.ClassA);
tvv = findViewById(R.id.tv_sel1);

public TextView getTextView() {    
        TextView tv = tvv;
            return tv;
       }
}

ClassB

select1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
                @Override

    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                Toast.makeText(getApplicationContext(),
"Select 1 - "    +parent.getSelectedItem().toString(),
Toast.LENGTH_LONG).show();

                ClassA txt = new ClassA();
                TextView tv = txt.getTextView();
                tv.setText(parent.getSelectedItem().toString());

            }

当我 运行 "debug" 打印时,应用程序强制关闭

tv.setText(parent.getSelectedItem().toString());

所以我输入的文本格式不对还是有其他错误?

在class中你应该设置一个方法来设置textview上的文本:

Class答:

public void setText(String text) {    
    tvv.setText(text);
   }

Class乙:

ClassA.setText(parent.getSelectedItem().toString());