考虑这个plunker
Grandchild Component
<button (click)="back2click()"></button>
@Input() from2;
@Output()
back2 = new EventEmitter<any>();
back2click() {
this.back2.emit('hi');
}
Child Component
changeDetection: ChangeDetectionStrategy.OnPush,
<my-app-n2 [from2]="from1" (back2)="handleback2($event)"></my-app-n2>
@Input() from1;
@Output() back1 = new EventEmitter<any>();
handleback2() {
this.back1.emit('hi')
}
Parent Component
<my-app-n1 [from1]="from" (back1)="handleback1($event)"></my-app-n1>
handleback1 () {
this.from.name = 'handline4';
}
我看到点击button时
back2click -> emit -> handleback2 -> emit -> handleback1
-> attribute is updated -> all child view are updated
这是令人困惑的，因为我希望只有父视图才能更新，因为changeDetection: ChangeDetectionStrategy.OnPush,是子组件中的配置。
我想我错过了什么，有人能指出正确的方向吗？
由于
答案 0 :(得分：1)
所有本机事件都标记了根组件的路径以进行一次检查。在FileInputStream in = new FileInputStream("form.pdf");
FileOutputStream out = new FileOutputStream("test.pdf");
PDDocument document = PDDocument.loadNonSeq(in,null);
document.setAllSecurityToBeRemoved(false);
Map<String, String> values = new HashMap<String, String>();
values.put("imiePracownika", "Grzegorz K.");
setFields(document, values);
PDAcroForm form = document.getDocumentCatalog().getAcroForm();
Document documentXML = form.getXFA().getDocument();
NodeList dataElements = documentXML.getElementsByTagName("xfa:data");
if (dataElements != null) {
for (int i = 0; i < dataElements.getLength(); i++) {
setXFAFields(dataElements.item(i), values);
}
}
RandomAccessBuffer r = new RandomAccessBuffer();
COSStream cosout = new COSStream(r);
TransformerFactory.newInstance().newTransformer().transform(new DOMSource(documentXML), new StreamResult(cosout.createUnfilteredStream()));
form.setXFA(new PDXFA(cosout));
document.save(out);
document.close();
private void setFields(PDField field, Map<String, String> values) throws IOException {
List<COSObjectable> kids = field.getKids();
if (kids != null) {
for (COSObjectable pdfObj : kids) {
if (pdfObj instanceof PDField) {
setFields((PDField) pdfObj, values);
}
}
} else {
// remove the [0] from the name to match values in our map
String partialName = field.getPartialName().replaceAll("\\[\\d\\]", "");
if (!(field instanceof PDSignatureField) && values.containsKey(partialName)) {
field.setValue(values.get(partialName));
}
}
}
public void setFields(PDDocument pdfDocument, Map<String, String> values) throws IOException {
@SuppressWarnings("unchecked")
List<PDField> fields = pdfDocument.getDocumentCatalog().getAcroForm().getFields();
for (PDField pdField : fields) {
setFields(pdField, values);
}
}
public void setXFAFields(Node pNode, Map<String, String> values) throws IOException {
if (values.containsKey(pNode.getNodeName())) {
pNode.setTextContent(values.get(pNode.getNodeName()));
} else {
NodeList childNodes = pNode.getChildNodes();
if (childNodes != null) {
for (int i = 0; i < childNodes.getLength(); i++) {
setXFAFields(childNodes.item(i), values);
}
}
}
}
模板中，您使用的是原生Grandchild Component事件：
click因此，组件的层次结构被标记为一次检查。
<button (click)="back2click()"></button>
有关变化检测的最全面解释，请阅读：
要详细了解 Root Component -> ViewState.ChecksEnabled = true
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...
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Parent -> ViewState.ChecksEnabled = true
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Child (onPush) -> ViewState.ChecksEnabled = true
|
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Grand child (event triggered here) -> markForCheck() -> ViewState.ChecksEnabled = true
，请参阅this answer并阅读本文：