好吧，材料表似乎没有 api 文档，我也找不到任何技巧来做到这一点，但是我们可以调整我们的数据来支持这一点，根据您的第二个示例，我们可以将数据改造成新的json，我们可以得到我们预期的结果。
第 1 步：
const originalData = [
{ id: 1, name: 'Hydrogen', weight: 1.0079, descriptions: ['row1', 'row2'] },
{ id: 2, name: 'Helium', weight: 4.0026, descriptions: ['row1', 'row2', 'row3'] },
{ id: 3, name: 'Lithium', weight: 6.941, descriptions: ['row1', 'row2'] },
{ id: 4, name: 'Beryllium', weight: 9.0122, descriptions: ['row1', 'row2', 'row3'] },
{ id: 5, name: 'Boron', weight: 10.811, descriptions: ['row1'] },
{ id: 6, name: 'Carbon', weight: 12.0107, descriptions: ['row1', 'row2', 'row3'] },
{ id: 7, name: 'Nitrogen', weight: 14.0067, descriptions: ['row1'] },
{ id: 8, name: 'Oxygen', weight: 15.9994, descriptions: ['row1'] },
{ id: 9, name: 'Fluorine', weight: 18.9984, descriptions: ['row1', 'row2', 'row3'] },
{ id: 10, name: 'Neon', weight: 20.1797, descriptions: ['row1', 'row2', 'row3'] },
]; //original data
const DATA = originalData.reduce((current, next) => {
next.descriptions.forEach(b => {
current.push({ id: next.id, name: next.name, weight: next.weight, descriptions: b })
});
return current;
}, []);//iterating over each one and adding as the description
console.log(DATA)
const ELEMENT_DATA: PeriodicElement[] = DATA; //adding data to the element data
第二步
这将是您的第二个 stackblitz 链接。
getRowSpan(col, index) {
return this.spans[index] && this.spans[index][col];
}
第三步
因为它是根据您的第二个链接
constructor() {
this.cacheSpan('Priority', d => d.id);
this.cacheSpan('Name', d => d.name);
this.cacheSpan('Weight', d => d.weight);
}
/**
* Evaluated and store an evaluation of the rowspan for each row.
* The key determines the column it affects, and the accessor determines the
* value that should be checked for spanning.
*/
cacheSpan(key, accessor) {
for (let i = 0; i < DATA.length;) {
let currentValue = accessor(DATA[i]);
let count = 1;
// Iterate through the remaining rows to see how many match
// the current value as retrieved through the accessor.
for (let j = i + 1; j < DATA.length; j++) {
if (currentValue != accessor(DATA[j])) {
break;
}
count++;
}
if (!this.spans[i]) {
this.spans[i] = {};
}
// Store the number of similar values that were found (the span)
// and skip i to the next unique row.
this.spans[i][key] = count;
i += count;
}
}
第四步
使用索引向下传递到行跨度并隐藏不需要的行
<ng-container matColumnDef="id">
<th mat-header-cell *matHeaderCellDef> Priority </th>
<td mat-cell *matCellDef="let data;let i = dataIndex" [attr.rowspan]="getRowSpan('Priority',i)" [style.display]="getRowSpan('Priority', i) ? '' : 'none'">
{{ data.id }} </td>
</ng-container>
<ng-container matColumnDef="name">
<th mat-header-cell *matHeaderCellDef> Name </th>
<td mat-cell *matCellDef="let data;let i = dataIndex" [attr.rowspan]="getRowSpan('Name',i)" [style.display]="getRowSpan('Name', i) ? '' : 'none'">
{{ data.name }} </td>
</ng-container>
<ng-container matColumnDef="weight">
<th mat-header-cell *matHeaderCellDef> Weight </th>
<td mat-cell *matCellDef="let data;let i = dataIndex" [attr.rowspan]="getRowSpan('Weight',i)" [style.display]="getRowSpan('Weight', i) ? '' : 'none'">
{{ data.weight }} </td>
</ng-container>
<ng-container matColumnDef="descriptions">
<th mat-header-cell *matHeaderCellDef> Descriptions </th>
<td mat-cell *matCellDef="let data"> {{ data.descriptions }} </td>
</ng-container>
<tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
<tr mat-row *matRowDef="let row; columns: displayedColumns;"></tr>
</table>
Here is the demo