Form adalah tampilan user interface yang disediakan oleh bahasa pmrograman agar mudah untuk menjalankan sebuah program. Event handler adalah sebuah method yang dapat mendeteksi suatu kejadian yang terjadi pada sebuah form, contoh ketika sebuah button di Click maka program akan melakukan sebuah eksekusi perintah yang ada pada event handlernya.
Pada contoh code program berikut adalah Event Handler yang ada pada sebuah button, jika button tersebut di Click maka akan memunculkan Messagebox.
C sharp
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
namespace OOP_praktikumForm
{
public partial class MainForm : Form
{
public MainForm()
{
InitializeComponent();
}
//event Handler
void BtnLihatClick(object sender, EventArgs e)
{
MessageBox.Show("Nama Anda "+textBox1.Text+"\t\nAlamat Anda = "+textBox2.Text);
}
}
}
Java
//Event Handler
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
JOptionPane.showMessageDialog(mainPanel, "Nama anda "+this.jTextField1.getText()+", \t\nAlamat Anda "+this.jTextField2.getText(), "Form Java dan Event Handler", 1);
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JTextField jTextField1;
private javax.swing.JTextField jTextField2;
private javax.swing.JPanel mainPanel;
private javax.swing.JProgressBar progressBar;
private javax.swing.JLabel statusAnimationLabel;
private javax.swing.JLabel statusMessageLabel;
private javax.swing.JPanel statusPanel;
// End of variables declaration
private final Timer messageTimer;
private final Timer busyIconTimer;
private final Icon idleIcon;
private final Icon[] busyIcons = new Icon[15];
private int busyIconIndex = 0;
private JDialog aboutBox;
C++
#pragma once
namespace formcpp_test {
using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;
/// <summary>
/// Summary for Form1
/// </summary>
public ref class Form1 : public System::Windows::Forms::Form
{
public:
Form1(void)
{
InitializeComponent();
//
//TODO: Add the constructor code here
//
}
protected:
/// <summary>
/// Clean up any resources being used.
/// </summary>
~Form1()
{
if (components)
{
delete components;
}
}
private: System::Windows::Forms::Label^ label1;
private: System::Windows::Forms::TextBox^ textBox1;
private: System::Windows::Forms::TextBox^ textBox2;
private: System::Windows::Forms::Label^ label2;
private: System::Windows::Forms::Button^ button1;
protected:
private:
/// <summary>
/// Required designer variable.
/// </summary>
System::ComponentModel::Container ^components;
#pragma region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
void InitializeComponent(void)
{
this->label1 = (gcnew System::Windows::Forms::Label());
this->textBox1 = (gcnew System::Windows::Forms::TextBox());
this->textBox2 = (gcnew System::Windows::Forms::TextBox());
this->label2 = (gcnew System::Windows::Forms::Label());
this->button1 = (gcnew System::Windows::Forms::Button());
this->SuspendLayout();
//
// label1
//
this->label1->AutoSize = true;
this->label1->Location = System::Drawing::Point(33, 45);
this->label1->Name = L"label1";
this->label1->Size = System::Drawing::Size(55, 13);
this->label1->TabIndex = 0;
this->label1->Text = L"Username";
//
// textBox1
//
this->textBox1->Location = System::Drawing::Point(36, 85);
this->textBox1->Name = L"textBox1";
this->textBox1->Size = System::Drawing::Size(222, 20);
this->textBox1->TabIndex = 1;
//
// textBox2
//
this->textBox2->Location = System::Drawing::Point(36, 151);
this->textBox2->Name = L"textBox2";
this->textBox2->Size = System::Drawing::Size(222, 20);
this->textBox2->TabIndex = 3;
//
// label2
//
this->label2->AutoSize = true;
this->label2->Location = System::Drawing::Point(33, 111);
this->label2->Name = L"label2";
this->label2->Size = System::Drawing::Size(39, 13);
this->label2->TabIndex = 2;
this->label2->Text = L"Alamat";
//
// button1
//
this->button1->Location = System::Drawing::Point(182, 212);
this->button1->Name = L"button1";
this->button1->Size = System::Drawing::Size(75, 23);
this->button1->TabIndex = 4;
this->button1->Text = L"Lihat";
this->button1->UseVisualStyleBackColor = true;
this->button1->Click += gcnew System::EventHandler(this, &Form1::button1_Click);
//
// Form1
//
this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
this->ClientSize = System::Drawing::Size(288, 262);
this->Controls->Add(this->button1);
this->Controls->Add(this->textBox2);
this->Controls->Add(this->label2);
this->Controls->Add(this->textBox1);
this->Controls->Add(this->label1);
this->FormBorderStyle = System::Windows::Forms::FormBorderStyle::FixedSingle;
this->MaximizeBox = false;
this->Name = L"Form1";
this->StartPosition = System::Windows::Forms::FormStartPosition::CenterScreen;
this->Text = L"Praktikum OOP";
this->ResumeLayout(false);
this->PerformLayout();
}
#pragma endregion
//event handler
private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e) {
MessageBox::Show ("Nama anda "+textBox1->Text+"\nAlamat Anda"+textBox2->Text);
}
};
}
