高度转换 - 厘米到英尺和英寸（反之亦然）

问题描述

我有一个编辑文本，用户可以用厘米以及英尺+英寸输入他的身高，例如。 5'11。我有一个目标单位的切换按钮，所以我希望当用户选择厘米时，它应该将输入的文本从英尺+英寸转换为厘米，反之亦然。
现在当我将高度转换为厘米，最后添加\。我认为这是因为我提出的文本观察者在计数达到3时最后添加\。

I have an edit text in which the user can enter his height in centimeters as well as in feet+inches, eg. 5'11". I have a toggle button for the target unit, so I want that when the user selects centimeters, it should convert the entered text from feet+inches into centimeters, and vice versa. Now when I am converting the height to centimeters it's adding "\"" at the end. I think it's because of the text watcher I have put which add "\"" at the end when count is reaching to 3.

public void onClick(View view) {
    switch (view.getId())
    {
        case R.id.btnCm:
            toggleHeightButton(R.id.btnCm,R.id.btnFeet,false);
            convertToCentimeter(enter_height);
            break;
        case R.id.btnFeet:
            toggleHeightButton(R.id.btnFeet,R.id.btnCm,true);
            enter_height.addTextChangedListener(new CustomTextWatcher(enter_height));
            break;
        case R.id.btnKg:
            toggleweightButton(R.id.btnKg,R.id.btnpound,false);
            break;
        case R.id.btnpound:
            toggleweightButton(R.id.btnpound,R.id.btnKg,true);
            break;
    }
}

public class CustomTextWatcher implements TextWatcher {
    private EditText mEditText;

    public CustomTextWatcher(EditText enter_height) {
        mEditText = enter_height;
    }

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

    public void onTextChanged(CharSequence s, int start, int before, int count) {
    }

    public void afterTextChanged(Editable s) {
        int count = s.length();
        String str = s.toString();
        if (count == 1) {
            str = str + "'";
        } else if (count == 2) {
            return;
        } else if (count == 3) {
            str = str + "\"";
        } else if ((count > 4) && (str.charAt(str.length() - 1) != '\"') ){
            str = str.substring(0, str.length() - 2) + str.charAt(str.length() - 1) + "\"";
        } else {
            return;
        }

        mEditText.setText(str);
        mEditText.setSelection(mEditText.getText().length());
    }
}

推荐答案

这可以通过正则表达式轻松完成，但我认为您应该首先尝试更简单的方法。

This can be easily done with regular expressions, but I think you should try the more straightforward way first.

基本上，格式就像 xx'xx。我们可以使用' deliminator 拆分字符串。这样，数组的第一项是英尺数。

Basically, the format is like xx'xx". We can split the string using the ' deliminator. That way, the first item of the array is the number of feet.

然后，我们剩下拆分字符串的第二项： xx 。为此，我们只需将其子串以删除最后一个字符，然后我们就可以获得英寸数！

Then, we have the second item of the split string left: xx". For this, we just need to substring it to remove the last character and then we can get the number of inches!

尝试自己编写代码！

如果你真的被卡住了，这就是解决方案：

If you're really stuck, here's the solution:

String str = s.toString();
String[] splitString = str.split("'");
String firstItem = splitString[0];
try {
    int feet = Integer.parseUnsignedInt(firstItem);
    String secondPart = splitString[1].substring(0, splitString[1].length() - 1);
    int inches = Integer.parseUnsignedInt(secondPart);
    // YAY! you got your feet and inches!
    System.out.println(feet);
    System.out.println(inches);
} catch (NumberFormatException e) {
    return;
}

这是使用r的解决方案egex：

And here's a solution using regex:

String str = s.toString();
Pattern pattern = Pattern.compile("(\\d+)'((\\d+)\")?");
Matcher matcher = pattern.matcher(str);
if (!matcher.matches()) {
    return;
}

int feet = Integer.parseUnsignedInt(matcher.group(1));
String inchesStr = matcher.group(3);
int inches = 0;
if (inchesStr != null) {
    inches = Integer.parseUnsignedInt(inchesStr);
}

// YAY! you got your feet and inches!

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