输入框进行换行

<textarea id="input-id" v-model="textarea" class="sport_transparent-input" :rows="2" placeholder="请输入内容，Shift+Enter换行" 
                                        @keydown="handleKeydown"></textarea>
 handleKeydown(event) {
                if (event.key === 'Enter' && event.shiftKey) {
                    // Shift + Enter for newline
                    const cursorPos = event.target.selectionStart;
                    this.textarea =
                        this.textarea.substring(0, cursorPos) + '\n' + this.textarea.substring(cursorPos);
                    this.$nextTick(() => {
                        event.target.selectionStart = cursorPos + 1;
                        event.target.selectionEnd = cursorPos + 1;
                    });
                    event.preventDefault();
                } else if (event.key === 'Enter' && !event.shiftKey) {
                    // Enter for submit
                    this.sumit();
                    event.preventDefault();
                }
            },