ردیابی تغییرات اعمال شده بر روی خصوصیت 

<app-customer-info FormIsReadOnly="true"></app-customer-info>

@Component({
    selector: 'app-customer-info',
    templateUrl: './customer-info.component.html',
    styleUrls: ['./customer-info.component.css']
})
export class CustomerInfoComponent implements OnInit {
    private _formIsReadOnly: boolean;

    @Input()
    set FormIsReadOnly(value: boolean) {
        if (typeof (value) != 'boolean')
            throw new Error(`${value} type is not boolean.`);
        this._formIsReadOnly = value;
    }

    get FormIsReadOnly(): boolean { return this._formIsReadOnly; }

    constructor() { }

    ngOnInit() {
    }
}

import { Component, OnInit, Input, OnChanges, SimpleChange } from '@angular/core';
import { ICustomerInfo } from '../../core/model/ICustomerInfo';

@Component({
    selector: 'app-customer-info',
    template: '<ul>< li *ngFor="let change of changeLog">{{change }}</li></ul>',
    styleUrls: ['./customer-info.component.css']
})
export class CustomerInfoComponent implements OnChanges {
    changeLog: string[] = [];

    @Input() FormIsReadOnly: boolean;

    ngOnChanges(changes: { [propKey: string]: SimpleChange }) {
        let log: string[] = [];
        for (let propName in changes) {
            let changedProp = changes[propName];
            let to = JSON.stringify(changedProp.currentValue);
            if (changedProp.isFirstChange()) {
                log.push(`Initial value of ${propName} set to ${to}`);
            } else {
                let from = JSON.stringify(changedProp.previousValue);
                log.push(`${propName} changed from ${from} to ${to}`);
            }
        }
        this.changeLog.push(log.join(', '));
    }

    constructor() { }
}

•    Initial value of FormIsReadOnly set to true
•    FormIsReadOnly changed from true to "trued"
•    FormIsReadOnly changed from "trued" to "true"
•    FormIsReadOnly changed from "true" to "truef"
•    FormIsReadOnly changed from "truef" to "true"
•    FormIsReadOnly changed from "true" to "tru"
•    FormIsReadOnly changed from "tru" to "tr"
•    FormIsReadOnly changed from "tr" to "t"
•    FormIsReadOnly changed from "t" to ""
•    FormIsReadOnly changed from "" to "t"
•    FormIsReadOnly changed from "t" to "tr"
•    FormIsReadOnly changed from "tr" to "tru"
•    FormIsReadOnly changed from "tru" to "true"

Googler: Last but not the list is the Googlers, they are the type of programmer that can’t finish a function of code without opening browser and search for the basic syntax that they always forget
 

Work in progress to add support for covariant return types to the .NET runtime. Soon we'll be able to override a virtual method returning `object` with a method returning `string`. Because of how array variance works, weird things might be possible in IL. 

class Base
{
    public virtual IntPtr[] Fun() => null;
}

// This is obvious pseude-code because C# won't let us introduce methods differing
// in return type. C# also requires to be explicit about "virtual" and "override".
// But IL... not so much.
class Derived : Base
{
    // overrides Base.Fun on 32bit platforms.
    public override uint[] Fun() => null;

    // overrides Base.Fun on 64bit platforms.
    public override ulong[] Fun() => null;
}

Firstly, it’s not a done deal. An offer has been made, and Opera’s board has recommended that shareholders accept it. But shareholders need to vote and governments need to be consulted. 

These are the customer-reported issues addressed in 15.9.7:

• Crashes when expanding variables!.
• /DEBUG:FASTLINK + C7 + PCH crashes debugger.
• Native C++ application crashes because of stack corruption with VS 2017 15.9.2.
• Incorrect Release Mode code.
• Xamarin Unobserved Task Exception WebRequest.
• Link /SOURCELINK option seems to do nothing. This fixes Source Link for Managed C++ Debugging.
• Fixed an issue with corruption of AVX/MPX/AVX512 registers while Debugging.
• Update of Microsoft.VCLibs.140.00.UWPDestkop framework packages for C++ UWP DesktopBridge applications adding support for ARM64.
• Corrected incorrect version of VCToolsRedistVersion in Microsoft.VCToolsVersion.default.props.
• Corrected unsigned embedded dll for VC Redist installers.
• SSDT/Web Tools: We fixed an issue where SQL LocalDB was not installed on Polish, Turkish, and Czech locales.
• SSDT: We fixed an issue affecting SQL Server Analysis Services (Method not found exception when clicking on UI).
• SSDT: We fixed an accessibility issue which was causing the contents of a table not to be visible in the result window when using High-Contrast mode.

Security Advisory Notices

• WorkflowDesigner XOML deserialization allows code execution.
• .NET Framework and Visual Studio Spoofing Vulnerability. 

Kent’s rules, from Extreme Programming Explained are:

• Runs all the tests
• Has no duplicated logic. Be wary of hidden duplication like parallel class hierarchies
• States every intention important to the programmer
• Has the fewest possible classes and methods

In my experience, these don’t quite serve the needs of software design. My four rules might be that a well-designed system:

• is well-covered by passing tests.
• has no abstractions not directly needed by the program.
• has unambiguous behavior.
• requires the fewest number of concepts.

Top Issues Fixed in Visual Studio 2019 RC.1

• Visual Studio 2019 Preview 4 crash if closing undocked Window.
• Intellisense error: C++11 static constexpr member initialization causes "member may not be initialized".
• Start Page "Remove From List" stops working.
• $(VCIDEInstallDir) is an invalid path. Missing backslash in Microsoft.Cpp.Common.props.
• Visual Studio 2019 Preview 2.0+ crashes when opening soultion filter.
• Manage Extensions toolbar throws exception.
• Fixed rendering of the Import and Export Settings Wizard when running per-monitor aware
• Fixed sizing of the New Project Dialog when running per-monitor aware
• Made a set of visual refinements to the start window 

Don’t be a clean code zealot. Clean code is not a goal. It’s an attempt to make some sense out of the immense complexity of systems we’re dealing with