Question

如何使用C＃将lib的@Component({ selector: 'my-app', providers: [FormBuilder], template: ` <div> Checkbox values: {{alertForm.value | json}} <mark> Is Form Valid: {{alertForm.valid}} </mark> <-- WHY IS FORM VALID ALWAYS FALSE? Does Fields have error: {{alertForm.get('fields').hasError('checkboxSelected')}} </div> <form [formGroup]="alertForm"> <fieldset class="form-group" formGroupName="fields"> <legend class="col-md-4"> Fields</legend> <div class="col-md-8 checkbox column-2"> <label *ngFor="let type of types.controls; let i=index"> <input name="fieldsAdd" type="checkbox" [formControl]="type" /> {{fields[i].name}} </label> </div> </fieldset> </form> ` }) export class App implements OnInit { alertForm: FormGroup; fields = [{name:"field1", checked: false}, {name:"field2", checked: false}]; constructor(private fb: FormBuilder) {} ngOnInit() { this.alertForm = this.fb.group({ fields: this.fb.array([], this.checkboxValidator) }); const controlArray = <FormArray>this.alertForm.controls['fields']; this.fields.map(field => controlArray.push(this.fb.control(field.checked))); } checkboxValidator(control: AbstractControl) { return { 'checkboxSelected': !(control.value.indexOf(true) >= 0) }; } get types(): FormArray { return this.alertForm.get('fields') as FormArray; }; }属性转换为foreach？我需要对每个字符串做一些事情，我需要一种foreach方式吗？任何人都可以提供帮助。

id

这是我尝试过的，虽然它返回null。

<map>
  <lib id="blue" revision="58399">
    <part id="2732" type="ch"/>
    <part id="2732" type="ls"/>
    <part id="2732" type="rs"/>
    <part id="2733" type="ch"/>
  </lib>
  <lib id="black" revision="26609">
    <part id="2109" type="cc"/>
    <part id="2109" type="lc"/>
    <part id="2109" type="rc"/>
  </lib>
</map>

Answer 1

有多种方法可以获得id元素的lib属性。

这是公共代码（xml变量）：

var xml = @"<map>
             <lib id=""blue"" revision=""58399"">
                 <part id=""2732"" type=""ch""/>
                 <part id=""2732"" type=""ls""/>
                 <part id=""2732"" type=""rs""/>
                 <part id=""2733"" type=""ch""/>
             </lib>
                 <lib id=""black"" revision=""26609"">
                 <part id=""2109"" type=""cc""/>
                 <part id=""2109"" type=""lc""/>
                 <part id=""2109"" type=""rc""/>
             </lib>
           </map>";

这是一个：

var xdoc = XDocument.Parse(xml);
foreach (var lib in xdoc.Descendants("lib"))
    Console.WriteLine(lib.Attribute("id").Value);

2：

var xdoc = XDocument.Parse(xml);
foreach (var item in xdoc.Root.Elements("lib"))
    Console.WriteLine(item.Attribute("id").Value);

三（使用XPath）：

var xmlDoc = new XmlDocument();
xmlDoc.LoadXml(xml);
foreach (XmlAttribute attr in xmlDoc.SelectNodes("/map/lib/@id"))
    Console.WriteLine(attr.Value);

使用C＃反序列化XML

1 个答案: