java - 使用 ListView 中的值填充新对话框中的 EditText

Question

嘿，我正在尝试使用 ListView 中的值填充新对话框中的 EditText。问题是我得到了

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.EditText.setText(java.lang.CharSequence)' on a null object

我在从 ListView 获得的值上放置了一个 Toast，它起作用了，它返回了特定的值。当我尝试调用 .setText(ValueFromListView) 时出现错误，我不明白为什么。谁能帮我这个？这是代码:

@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, final int position, final long id) {
    final Dialog dialog = new Dialog(MainActivity.this);
    dialog.setTitle("Edit item...");
    dialog.setContentView(R.layout.custom_dialog_edit_delete);
    dialog.show();

    Button button_UPDATE = (Button) dialog.findViewById(R.id.custom_dialog_edit_delete_button_UPDATE);
    Button button_CANCEL = (Button) dialog.findViewById(R.id.custom_dialog_edit_delete_button_CANCEL);
    Button button_DELETE = (Button) dialog.findViewById(R.id.custom_dialog_edit_delete_button_DELETE);

    // GET PRODUCT REFERENCES
    Cursor cursor = (Cursor) parent.getItemAtPosition(position);
    String productName = cursor.getString(cursor.getColumnIndex(DBAdapter.KEY_PRODUCT));
    String productPrice = cursor.getString(cursor.getColumnIndex(DBAdapter.KEY_PRICE));
    String productType = cursor.getString(cursor.getColumnIndex(DBAdapter.KEY_TYPE));
    Toast.makeText(MainActivity.this, productName + " " + productPrice + " " + productType, Toast.LENGTH_SHORT).show(); 

    EditText prodField = (EditText) findViewById(R.id.custom_dialog_edit_delete__productName);
    prodField.setText(productName); // This is the line that i get the null pointer exception
}

Answer 1

EditText 在您的对话框中可用，因此您必须在创建 EditText 对象时提供您的对话框的引用。

EditText prodField = (EditText) dialog.findViewById(R.id.custom_dialog_edit_delete__productName);