TChilkatHashtable Delphi ActiveX Reference Documentation

TChilkatHashtable

Current Version: 9.5.0.72

Represents a collection of key/value pairs that are stored in a hash table.

Note: This class was added in Chilkat v9.5.0.51

Importing the Chilkat ActiveX into Delphi

Important: When upgrading to a new version of Chilkat, make sure to re-imported ActiveX DLL into Delphi to regenerate the files described below.

Two things are required to use an ActiveX in Delphi:

  1. The ActiveX DLL needs to be registered via regsvr32 on the system where the Delphi application runs. See How To Register ActiveX DLLs for detailed information.
  2. See also: ActiveX Registration Tutorial
  3. The ActiveX component needs to be "imported". Use the Delphi Import Component Wizard to import the Chilkat type library. This creates the following files: Chilkat_v9_5_0_TLB.pas and Chilkat_v9_5_0_TLB.dcr. The Chilkat_v9_5_0_TLB.pas should be added to your project.

To import the Chilkat type library, do the following:

  1. In the Delphi RAD Studio, select the menu item "Component" --> "Import a Type Library".
  2. Find "Chilkat ActiveX v9.5.0" in the list and select it. This will only appear in the list if the ChilkatAx-9.5.0-win32.dll (or ChilkatAx-9.5.0-x64.dll) has been registered w/ regsvr32.
  3. Check the "Generate Component Wrappers" checkbox.
  4. Select a directory where the unit files (.pas and .dcr) should be generated.
  5. Select "Create Unit" and then "Finish".
  6. Add the .pas to your Delphi project.

To use a Chilkat ActiveX object in your Delphi code, add "Chilkat_v9_5_0_TLB" to the "uses" statement. For example:

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_v9_5_0_TLB;

Object Creation

var
obj: TChilkatHashtable;
...
begin
obj := TChilkatHashtable.Create(Self);
...
// When finished, free the object instance.
obj.Free();

Properties

LastMethodSuccess
property LastMethodSuccess: Integer

Indicate whether the last method call succeeded or failed. A value of 1 indicates success, a value of 0 indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = 1 and failure = 0.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to 1. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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Methods

AddFromXmlSb
function AddFromXmlSb(sbXml: TChilkatStringBuilder): Integer;
Introduced in version 9.5.0.64

Adds to the hash table from XML previously created by calling ToXmlSb.

Returns 1 for success, 0 for failure.

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AddInt
function AddInt(key: WideString; value: Integer): Integer;
Introduced in version 9.5.0.51

Adds or replaces an entry with the given key and integer value to the hash table. Returns 1 if a new hash entry was added or replaced. Returns 0 if an out-of-memory condition occurred.

Returns 1 for success, 0 for failure.

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AddQueryParams
function AddQueryParams(queryParams: WideString): Integer;
Introduced in version 9.5.0.62

Adds URL query parameters into the hashtable. The queryParams has the form: "field1=value1&field2=value2&field3=value3...". It is assumed that the values are URL encoded, and this method automatically URL decodes the values prior to inserting into the hashtable.

Returns 1 for success, 0 for failure.

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AddStr
function AddStr(key: WideString; value: WideString): Integer;
Introduced in version 9.5.0.51

Adds or replaces an entry with the given key and string value to the hash table. Returns 1 if a new hash entry was added or replaced. Returns 0 if an out-of-memory condition occurred.

Returns 1 for success, 0 for failure.

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Clear
procedure Clear();
Introduced in version 9.5.0.51

Removes all elements from the Hashtable.

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ClearWithNewCapacity
function ClearWithNewCapacity(capacity: Integer): Integer;
Introduced in version 9.5.0.51

Removes all elements from the Hashtable and re-sizes with the specified capacity.

The capacity is the number of buckets in the hash table. In the case of a "hash collision", a single bucket stores multiple entries, which must be searched sequentially. One rule of thumb is to set the capacity to twice the number of expected items to be hashed. It's also preferable to set the capacity to a prime number. (The 1st 10,000 prime numbers are listed here: https://primes.utm.edu/lists/small/10000.txt )

The initial default capacity of the hash table is 521.

Returns 1 for success, 0 for failure.

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Contains
function Contains(key: WideString): Integer;
Introduced in version 9.5.0.51

Determines if a given key is contained within the hash table. Returns 1 if the key exists, otherwise returns 0.

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ContainsIntKey
function ContainsIntKey(key: Integer): Integer;
Introduced in version 9.5.0.64

Determines if a given key is contained within the hash table. Returns 1 if the key exists, otherwise returns 0.

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GetKeys
function GetKeys(strTable: TChilkatStringTable): Integer;
Introduced in version 9.5.0.62

Appends the complete set of hashtable key strings to strTable.

Returns 1 for success, 0 for failure.

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LookupInt
function LookupInt(key: WideString): Integer;
Introduced in version 9.5.0.51

Returns the integer value associated with the specified key. If the key is not in the hash table, the return value is 0.

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LookupStr
function LookupStr(key: WideString): WideString;
Introduced in version 9.5.0.51

Returns the string value associated with the specified key.

Returns a zero-length WideString on failure

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Remove
function Remove(key: WideString): Integer;
Introduced in version 9.5.0.51

Removes the entry with the specified key from the hash table. Returns 1 if the key existed and was removed. Returns 0 if the key did not already exist.

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ToXmlSb
function ToXmlSb(sbXml: TChilkatStringBuilder): Integer;
Introduced in version 9.5.0.64

Serializes the hash table to XML format. The XML is appended to sbXml.

Returns 1 for success, 0 for failure.

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