ionic - 如何在 ion-header 中对长字符串进行自动换行

This is my code, and I tried text-wrap , inside ion-header still can not show whole title.

<ion-header>
  <ion-toolbar text-wrap color="danger">
    <ion-buttons>
        <button ion-button navPop icon-only>
            <ion-icon ios="ios-arrow-back" md="md-arrow-back"></ion-icon>
        </button>
    </ion-buttons>
    <ion-title>{{new.title}}</ion-title>
  </ion-toolbar>
</ion-header>

更新

<ion-header>
  <ion-toolbar color="danger">
    <ion-buttons>
        <button ion-button navPop icon-only>
            <ion-icon ios="ios-arrow-back" md="md-arrow-back"></ion-icon>
        </button>
    </ion-buttons>
    <ion-item color="danger" text-wrap>
     <ion-title >{{new.title}}</ion-title>
    </ion-item>
  </ion-toolbar>
</ion-header>

我尝试在那里添加 ion-item，但仍然不适合我.

.ios .toolbar-title {
   text-overflow: inherit;
   white-space: normal;
   text-align: left;
   font-size:1.3em;
}

.md .toolbar-title {
   text-overflow: inherit;
   white-space: normal;
   text-align: left;
   font-size:1.3em;
}

.toolbar-title {
   text-overflow: inherit;
   white-space: normal;
}

.toolbar-title {
   text-overflow: unset;
   white-space: unset;
}