// 处理超出字后面...
export function doStr(str, n) {
    let totalCount = 0;
    let txt = "";
    if (str) {
        for (var i = 0; i < str.length; i++) {
            let c = str.charCodeAt(i);
            if ((c >= 0x0001 && c <= 0x007e) || (0xff60 <= c && c <= 0xff9f)) {
                totalCount++;
            } else {
                totalCount += 2;
            }
            if (totalCount <= n) {
                txt += str[i];
            } else {
                txt += '...';
                return txt
            }
        }
    }
    return txt;
}