插入表情(文字)到指定光标位置

函数代码:

    faceClick(idx: number, word: string) {
        let { temList } = this.state;
        temList[idx] = this.insertText(
            this.refs[`script-input-${idx}`],
            `[${word}]`
        );
        this.setState({
            temList: [...temList]
        });
    }

    insertText(obj: any, str: string) {
        if (document.selection) {
            var sel = document.selection.createRange();
            sel.text = str;
        } else if (
            typeof obj.selectionStart === "number" &&
            typeof obj.selectionEnd === "number"
        ) {
            var startPos = obj.selectionStart,
                endPos = obj.selectionEnd,
                cursorPos = startPos,
                tmpStr = obj.value;
            obj.value =
                tmpStr.substring(0, startPos) +
                str +
                tmpStr.substring(endPos, tmpStr.length);
            cursorPos += str.length;
            obj.selectionStart = obj.selectionEnd = cursorPos;
        } else {
            obj.value += str;
        }
        return obj.value;
    }

JSX

    <input
        type="text"
        className="tem-input"
        value={item}
        placeholder="请输入内容"
        onChange={this.TemChange.bind(
            this,
            index
        )}
        ref={`script-input-${index}`}
    />
    <Face
        onClick={this.faceClick.bind(
            this,
            index
        )}
    />