Android 如何识别键盘上的空白

在

EditText

框中键入文本时，我想确定从键盘上按下了哪个键。我正在使用此代码，但它不起作用

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    // TODO Auto-generated method stub
    if (keyCode == KeyEvent.KEYCODE_SPACE) {

        Toast.makeText(MainActivity.this, "White space is clicked", Toast.LENGTH_LONG).show();
        return true;
    }

    return super.onKeyDown(keyCode, event);
}

---

我哪里出错了？

试试这个，它可能会对你有所帮助

boolean userPressedKey = false ;

yourEditText.addTextChangedListener(new TextWatcher() {
    public void afterTextChanged(Editable s) {
        userPressedKey = false ;
    }

    public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

    public void onTextChanged(CharSequence s, int start, int before, int count) {
        userPressedKey = true;
    }); 


public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (userPressedKey) {
        if (keyCode == KeyEvent.KEYCODE_SPACE) {
    Toast.makeText(MainActivity.this, "White space is clicked", Toast.LENGTH_LONG).show();
            return true;
        }
    }
    super.onKeyDown(keyCode, event);
}

---

您可以尝试以下代码----

---

}

我在EditText中输入数据，现在我想要的是当用户点击空格键时，新单词以一个特殊字符开头，如“$”。这就是编辑文本中空格后的每个单词的第一个字母都应该是“$”。若键盘提供建议，则在按下空格时，它会显示建议。查看此链接。这个问题出现了。

editText1.addTextChangedListener(new TextWatcher() {

    @Override
    public void afterTextChanged(Editable arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count,
            int after) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before,
            int count) {
        // TODO Auto-generated method stub
        String lastChar = s.toString().substring(s.length() - 1);
        if (lastChar.equals(" ")) {
            Toast.makeText(MainActivity.this, "space bar pressed",
                    Toast.LENGTH_SHORT).show();
        }
    }

});