复制粘贴用户输入

Question

我正在进行练习，我现在很库存。我必须复制UserInput，然后粘贴创建的字符串。谁能帮我吗？

这是我的代码：

public class CopyPasteActivity extends AppCompatActivity {
    private Button CopyButton;
    private Button PasteButton;
    private EditText UserInput;
    private TextView PasteText;
    private final static String TAG = "CopyPasteActivity";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_copy_paste);
        CopyButton = (Button) findViewById(R.id.copy_button);
        PasteButton = (Button) findViewById(R.id.paste_button);
        UserInput = (EditText) findViewById(R.id.user_input);
        PasteText = (TextView) findViewById(R.id.paste_text);
        final String userinput = new String();
        CopyButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                Log.d(TAG, "The button Copy was pressed");
               String userinput = UserInput.getText().toString();
            }
        });
        PasteButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                Log.d(TAG, "The button True was pressed");
                PasteText.setText(userinput);
            }
        });
    }
}

Answer 1

问题在于您在onCreate()内声明userinput并将其制成final，这使您无法稍后进行编辑。同样在CopyButton click listener内部，您正在为userinput创建一个新的本地变量，其范围仅限于该侦听器。

将String userinput = new String();移动到onCreate()外，删除final，然后将CopyButton侦听器中的行更改为

userinput = UserInput.getText().toString();

Answer 2

您不应在CopyButton.setOnClickListener内定义userinput变量。将其定义为您的类或实例变量，以便您的PasteButton.setOnClickListener看到它。这样：

String userinput;
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_copy_paste);
    CopyButton = (Button) findViewById(R.id.copy_button);
    PasteButton = (Button) findViewById(R.id.paste_button);
    UserInput = (EditText) findViewById(R.id.user_input);
    PasteText = (TextView) findViewById(R.id.paste_text);
    CopyButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            Log.d(TAG, "The button Copy was pressed");
            userinput = UserInput.getText().toString();
        }
    });
    PasteButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            Log.d(TAG, "The button True was pressed");
            PasteText.setText(userinput);
        }
    });
}