复制粘贴用户输入

Question

我正在做一个练习，我现在有货了。我必须复制用户输入，然后粘贴创建的字符串。谁能帮帮我？

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

问题是您在 onCreate() 中声明了 userinput 并使其成为 final，这会阻止您稍后对其进行编辑。同样在 CopyButton click listener 中，您正在为 userinput 创建一个新的局部变量，其范围仅限于该侦听器。

将 String userinput = new String(); 移到 onCreate() 之外，删除 final，并将 CopyButton 侦听器中的行更改为

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

Answer 2

您不应在 CopyButton.setOnClickListener 中定义 userinput 变量。将其定义为您的 as class 或侦听器外部的实例变量，以便您的 PasteButton.setOnClickListener 应该看到它。像这样：

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);
        }
    });
}

复制粘贴用户输入

Copy Paste userinput

android

onclick

user-input

gettext

settext