34.winform之打开文件对话框

效果

实现

代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp4 {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e) {
            //点击弹出对话框
            OpenFileDialog openFileDialog = new OpenFileDialog();

            //设置对话框的标题
            openFileDialog.Title = "请选择要打开的文本文件";

            //设置对话框可以多选
            openFileDialog.Multiselect = false;

            //设置对话框的初始目录
            openFileDialog.InitialDirectory = @"C:\Users\22053\Desktop";

            //设置对话框的文件类型
            openFileDialog.Filter = "文本文件|*.txt|媒体文件|*.wmv|图片文件|*.png|所有文件|*.*";

            //展示对话框
            openFileDialog.ShowDialog();

            ////获得在打开的对话框中选中文件的路径
            string path = openFileDialog.FileName;

            if (path == "") {
                return;
            }

            using (FileStream fsRead = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Read)) {
                byte[] buffer = new byte[1024 * 1024 * 5];
                //实际读取到的字节数
                int r = fsRead.Read(buffer, 0, buffer.Length);

                textBox1.Text = Encoding.Default.GetString(buffer, 0, r);
            }
        }
    }
}

注意此处设置对话框的文件类型openFileDialog.Filter = "文本文件|*.txt|媒体文件|*.wmv|图片文件|*.png|所有文件|*.*"; 效果如下：