iPhone4 iOS5 如何以编程方式将字符串转换为二进制字符代码？

Question

可能的重复：
将 NSString 转换为 ASCII 二进制等效值（然后再次返回 NSString）

我想知道如何获取一个字符并将其转换为二进制字符串。

假设我有一个string ：

NSString* test = @"Test";

如何按从左到右的顺序将该字符串打印为每个字符的 ASCII 二进制代码：

T = decimal 84 = binary 1010100
e = decimal 101= binary 1100101

然后我想打印所有字符代码的总和序列

NSString binaryTest = @"10101001100101...";

Answer 1

这应该做你想要的：

    NSMutableString *finalString = [[NSMutableString alloc] init];
    NSMutableString *binary;
    NSMutableString *binaryReversed;

    // The original string
    NSString *test = @"Test";

    char temp;
    int i, j, digit, dec;

    // Loop through all the letters in the original string
    for (i = 0; i < test.length; i++) {
        // Get the character
        temp = [test characterAtIndex:i];
        dec = (int)temp;
        binary = [[NSMutableString alloc] initWithString:@""];
        // Convert the decimal value to binary representation
        // getting the remainders and storing them in an NSString
        while (dec != 0) {
            digit = dec % 2;
            dec = dec / 2;
            [binary appendFormat:@"%d", digit];
        }
        // Reverse the bit sequence in the NSString
        binaryReversed = [[NSMutableString alloc] initWithString:@""];
        for (j = (int)(binary.length) - 1; j >= 0; j--) {
            [binaryReversed appendFormat:@"%C", [binary characterAtIndex:j]];
        }
        // Append the bit sequence to the current letter to the final string
        [finalString appendString:binaryReversed];
        [binaryReversed release];
        [binary release];
    }
    // Just show off the result and release the finalString
    NSLog(@"%@ in binary: %@", test, finalString);
    [finalString release];