实现文件下载c++/cli
添加net空间，在窗体中添加2个textbox,4个标签label。2个按钮button。设置属性。源码如下：
namespace 下载 {
using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;
using namespace System::Net;
/// <summary>
/// Form1 摘要
/// </summary>
public ref class Form1 : public System::Windows::Forms::Form
{
public:
Form1(void)
{
InitializeComponent();
this->wc=gcnew System::Net::WebClient();
//this->textBox1->Text="http://ftp.pconline.com.cn/pub/download/201007/QQ2010.zip";//测试地址
//
//TODO: 在此处添加构造函数代码
//
}
protected:
/// <summary>
/// 清理所有正在使用的资源。
/// </summary>
~Form1()
{
if (components)
{
delete components;
}
}
private: System::Windows::Forms::Button^ button1;
protected:
private: System::Windows::Forms::Button^ button2;
private: System::Windows::Forms::TextBox^ textBox1;
private: System::Windows::Forms::Label^ label1;
private: System::Windows::Forms::Label^ label2;
private: System::Windows::Forms::Label^ label3;
private: System::Windows::Forms::Label^ label4;
private: System::Windows::Forms::ProgressBar^ progressBar1;
private: System::Net::WebClient ^wc;
private: System::Windows::Forms::TextBox^ textBox2;
private: System::Windows::Forms::Label^ label5;
private:
/// <summary>
/// 必需的设计器变量。
/// </summary>
System::ComponentModel::Container ^components;
#pragma region Windows Form Designer generated code
/// <summary>
/// 设计器支持所需的方法 - 不要
/// 使用代码编辑器修改此方法的内容。
/// </summary>
void InitializeComponent(void)
{
this->button1 = (gcnew System::Windows::Forms::Button());
this->button2 = (gcnew System::Windows::Forms::Button());
this->textBox1 = (gcnew System::Windows::Forms::TextBox());
this->label1 = (gcnew System::Windows::Forms::Label());
this->label2 = (gcnew System::Windows::Forms::Label());
this->label3 = (gcnew System::Windows::Forms::Label());
this->label4 = (gcnew System::Windows::Forms::Label());
this->progressBar1 = (gcnew System::Windows::Forms::ProgressBar());
this->textBox2 = (gcnew System::Windows::Forms::TextBox());
this->label5 = (gcnew System::Windows::Forms::Label());
this->SuspendLayout();
//
// button1
//
this->button1->Location = System::Drawing::Point(27, 160);
this->button1->Name = L"button1";
this->button1->Size = System::Drawing::Size(75, 23);
this->button1->TabIndex = 0;
this->button1->Text = L"下载";
this->button1->UseVisualStyleBackColor = true;
this->button1->Click += gcnew System::EventHandler(this, &Form1::button1_Click);
//
// button2
//
this->button2->Location = System::Drawing::Point(229, 160);
this->button2->Name = L"button2";
this->button2->Size = System::Drawing::Size(75, 23);
this->button2->TabIndex = 1;
this->button2->Text = L"取消";
this->button2->UseVisualStyleBackColor = true;
//
// textBox1
//
this->textBox1->Location = System::Drawing::Point(70, 23);
this->textBox1->Name = L"textBox1";
this->textBox1->Size = System::Drawing::Size(333, 21);
this->textBox1->TabIndex = 2;
//
// label1
//
this->label1->AutoSize = true;
this->label1->Location = System::Drawing::Point(23, 26);
this->label1->Name = L"label1";
this->label1->Size = System::Drawing::Size(23, 12);
this->label1->TabIndex = 4;
this->label1->Text = L"URI";
//
// label2
//
this->label2->AutoSize = true;
this->label2->Location = System::Drawing::Point(12, 95);
this->label2->Name = L"label2";
this->label2->Size = System::Drawing::Size(29, 12);
this->label2->TabIndex = 5;
this->label2->Text = L"进度";
//
// label3
//
this->label3->AutoSize = true;
this->label3->Location = System::Drawing::Point(406, 95);
this->label3->Name = L"label3";
this->label3->Size = System::Drawing::Size(41, 12);
this->label3->TabIndex = 6;
this->label3->Text = L"label3";
//
// label4
//
this->label4->AutoSize = true;
this->label4->Location = System::Drawing::Point(77, 125);
this->label4->Name = L"label4";
this->label4->Size = System::Drawing::Size(41, 12);
this->label4->TabIndex = 7;
this->label4->Text = L"label4";
//
// progressBar1
//
this->progressBar1->Location = System::Drawing::Point(82, 84);
this->progressBar1->Name = L"progressBar1";
this->progressBar1->Size = System::Drawing::Size(294, 23);
this->progressBar1->TabIndex = 8;
//
// textBox2
//
this->textBox2->Location = System::Drawing::Point(70, 55);
this->textBox2->Name = L"textBox2";
this->textBox2->Size = System::Drawing::Size(333, 21);
this->textBox2->TabIndex = 9;
//
// label5
//
this->label5->AutoSize = true;
this->label5->Location = System::Drawing::Point(12, 58);
this->label5->Name = L"label5";
this->label5->Size = System::Drawing::Size(53, 12);
this->label5->TabIndex = 10;
this->label5->Text = L"文件名称";
//
// Form1
//
this->AutoScaleDimensions = System::Drawing::SizeF(6, 12);
this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
this->ClientSize = System::Drawing::Size(459, 220);
this->Controls->Add(this->label5);
this->Controls->Add(this->textBox2);
this->Controls->Add(this->progressBar1);
this->Controls->Add(this->label4);
this->Controls->Add(this->label3);
this->Controls->Add(this->label2);
this->Controls->Add(this->label1);
this->Controls->Add(this->textBox1);
this->Controls->Add(this->button2);
this->Controls->Add(this->button1);
this->Name = L"Form1";
this->Text = L"Form1";
this->ResumeLayout(false);
this->PerformLayout();
}
#pragma endregion
private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e) {
if (wc->IsBusy)
{
wc->CancelAsync();
}
else
{ this->wc->DownloadProgressChanged += gcnew DownloadProgressChangedEventHandler(this,&Form1::wc_WebClient_DownloadProgressChanged);
this->wc->DownloadFileCompleted +=gcnew AsyncCompletedEventHandler(this,&Form1::wc_WebClient_OnDownloadFileCompleted);
if (this->textBox1->Text!="")
{ String ^s=this->textBox1->Text;
String ^k=s->Remove(0,s->LastIndexOf('/')+1);
this->textBox2->Text=k;
this-> wc->DownloadFileAsync(gcnew Uri(this->textBox1->Text),k);
}
else
MessageBox::Show("请输入下载地址");
}
}
private:void wc_WebClient_DownloadProgressChanged(Object ^sender,DownloadProgressChangedEventArgs ^e)
{
this->progressBar1->Value=e->ProgressPercentage;
this->label3->Text=e->ProgressPercentage.ToString()+"%";
this->label4->Text=String::Format("正在下载文件，当前下载{0}/{1}（字节）",e->BytesReceived,e->TotalBytesToReceive);
}
private: void wc_WebClient_OnDownloadFileCompleted(Object ^sender, AsyncCompletedEventArgs ^e)
{
MessageBox::Show("下载完成");
}
private: System::Void button2_Click(System::Object^ sender, System::EventArgs^ e) {
wc->CancelAsync();
}
};
}
最主要的是事件注册。其他就是对webclient类的了解和应用。
初学者参考，这里不能上传源码。有值得看的源码全部在csdn了。用户名jinyuttt
