使用此转换任何字符串数字为double当你需要int时，只需将数据类型从num和num2转换为int; 把所有的情况下，任何字符串double与Eng:"Bader Qandeel"

public static double str2doubel(String str) {
    double num = 0;
    double num2 = 0;
    int idForDot = str.indexOf('.');
    boolean isNeg = false;
    String st;
    int start = 0;
    int end = str.length();

    if (idForDot != -1) {
        st = str.substring(0, idForDot);
        for (int i = str.length() - 1; i >= idForDot + 1; i--) {
            num2 = (num2 + str.charAt(i) - '0') / 10;
        }
    } else {
        st = str;
    }

    if (st.charAt(0) == '-') {
        isNeg = true;
        start++;
    } else if (st.charAt(0) == '+') {
        start++;
    }

    for (int i = start; i < st.length(); i++) {
        if (st.charAt(i) == ',') {
            continue;
        }
        num *= 10;
        num += st.charAt(i) - '0';
    }

    num = num + num2;
    if (isNeg) {
        num = -1 * num;
    }
    return num;
}

String s = "12.34";
double num = Double.valueOf(s);

你可以使用double . parsedouble()将String转换为double类型:

String text = "12.34"; // example String
double value = Double.parseDouble(text);

对于你的案例，它看起来像你想要:

double total = Double.parseDouble(jlbTotal.getText());
double price = Double.parseDouble(jlbPrice.getText());

要将字符串转换回double类型，请尝试以下操作

String s = "10.1";
Double d = Double.parseDouble(s);

parseDouble方法将达到预期的效果，Double.valueOf()方法也是如此。

再次引用上面Robertiano的引用-因为这是迄今为止最通用和本地化自适应的版本。它值得一个完整的帖子!

另一个选择:

DecimalFormat df = new DecimalFormat(); 
DecimalFormatSymbols sfs = new DecimalFormatSymbols();
sfs.setDecimalSeparator(','); 
df.setDecimalFormatSymbols(sfs);
double d = df.parse(number).doubleValue();

使用此转换任何字符串数字为double当你需要int时，只需将数据类型从num和num2转换为int; 把所有的情况下，任何字符串double与Eng:"Bader Qandeel"

public static double str2doubel(String str) {
    double num = 0;
    double num2 = 0;
    int idForDot = str.indexOf('.');
    boolean isNeg = false;
    String st;
    int start = 0;
    int end = str.length();

    if (idForDot != -1) {
        st = str.substring(0, idForDot);
        for (int i = str.length() - 1; i >= idForDot + 1; i--) {
            num2 = (num2 + str.charAt(i) - '0') / 10;
        }
    } else {
        st = str;
    }

    if (st.charAt(0) == '-') {
        isNeg = true;
        start++;
    } else if (st.charAt(0) == '+') {
        start++;
    }

    for (int i = start; i < st.length(); i++) {
        if (st.charAt(i) == ',') {
            continue;
        }
        num *= 10;
        num += st.charAt(i) - '0';
    }

    num = num + num2;
    if (isNeg) {
        num = -1 * num;
    }
    return num;
}