SaveFileDialog.OverwritePrompt 属性

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

获取或设置一个值，该值指示如果用户指定的文件名已存在，Save As 对话框是否显示警告。

C#

public bool OverwritePrompt { get; set; }

属性值

Boolean

在用户指定的文件名存在的情况下，如果在覆盖该文件之前对话框对用户进行提示，则为 true；如果对话框不征得用户许可就自动覆盖现有文件，则为 false。 默认值是 true。

示例

下面的代码示例演示如何将 和 RichTextBox.LoadFile 方法与流配合使用RichTextBox.SaveFile。 它还演示了如何使用 FileName、 DefaultExt、 CreatePrompt和 OverwritePrompt 成员。

这是一个完整示例，可在将它复制到项目时运行。

C#

using System;
using System.Drawing;
using System.IO;
using System.Windows.Forms;

public partial class Form1: Form
{
    internal RichTextBox RichTextBox1;
    internal Button Button1;
    internal RichTextBox RichTextBox2;
    internal Button Button2;
    internal SaveFileDialog SaveFileDialog1;

    public Form1() : base()
    {   
        this.RichTextBox1 = new RichTextBox();
        this.Button1 = new Button();
        this.RichTextBox2 = new RichTextBox();
        this.Button2 = new Button();
        this.SaveFileDialog1 = new SaveFileDialog();
        this.SuspendLayout();
        this.RichTextBox1.Location = new Point(24, 64);
        this.RichTextBox1.Name = "RichTextBox1";
        this.RichTextBox1.TabIndex = 0;
        this.RichTextBox1.Text = "Type something here.";
        this.Button1.Location = new Point(96, 16);
        this.Button1.Name = "Button1";
        this.Button1.Size = new Size(96, 24);
        this.Button1.TabIndex = 1;
        this.Button1.Text = "Save To Stream";
        this.Button1.Click += new EventHandler(Button1_Click);
        this.RichTextBox2.Location = new Point(152, 64);
        this.RichTextBox2.Name = "RichTextBox2";
        this.RichTextBox2.TabIndex = 3;
        this.RichTextBox2.Text = 
            "It will be added to the stream and appear here.";
        this.Button2.Location = new Point(104, 200);
        this.Button2.Name = "Button2";
        this.Button2.Size = new Size(88, 32);
        this.Button2.TabIndex = 4;
        this.Button2.Text = "Save Stream To File";
        this.Button2.Click += new EventHandler(Button2_Click);
        this.ClientSize = new Size(292, 266);
        this.Controls.Add(this.Button2);
        this.Controls.Add(this.RichTextBox2);
        this.Controls.Add(this.Button1);
        this.Controls.Add(this.RichTextBox1);
        this.Name = "Form1";
        this.Text = "Form1";
        this.ResumeLayout(false);
    }

    public static void Main()
    {
        Application.Run(new Form1());
    }

    // Declare a new memory stream.
    MemoryStream userInput = new MemoryStream();

    // Save the content of RichTextBox1 to the memory stream, 
    // appending a LineFeed character.  
    private void Button1_Click(Object sender, EventArgs e)
    {
        RichTextBox1.SaveFile(userInput, RichTextBoxStreamType.PlainText);
        userInput.WriteByte(13);

        // Display the entire contents of the stream,
        // by setting its position to 0, to RichTextBox2.
        userInput.Position = 0;
        RichTextBox2.LoadFile(userInput, RichTextBoxStreamType.PlainText);
    }

    // Shows the use of a SaveFileDialog to save a MemoryStream to a file.
    private void Button2_Click(Object sender, EventArgs e)
    {
        // Set the properties on SaveFileDialog1 so the user is 
        // prompted to create the file if it doesn't exist 
        // or overwrite the file if it does exist.
        SaveFileDialog1.CreatePrompt = true;
        SaveFileDialog1.OverwritePrompt = true;

        // Set the file name to myText.txt, set the type filter
        // to text files, and set the initial directory to the 
        // MyDocuments folder.
        SaveFileDialog1.FileName = "myText";
        // DefaultExt is only used when "All files" is selected from 
        // the filter box and no extension is specified by the user.
        SaveFileDialog1.DefaultExt = "txt";
        SaveFileDialog1.Filter = 
            "Text files (*.txt)|*.txt|All files (*.*)|*.*";
        SaveFileDialog1.InitialDirectory = 
            Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);

        // Call ShowDialog and check for a return value of DialogResult.OK,
        // which indicates that the file was saved. 
        DialogResult result = SaveFileDialog1.ShowDialog();
        Stream fileStream;

        if (result == DialogResult.OK)
        {
            // Open the file, copy the contents of memoryStream to fileStream,
            // and close fileStream. Set the memoryStream.Position value to 0 
            // to copy the entire stream. 
            fileStream = SaveFileDialog1.OpenFile();
            userInput.Position = 0;
            userInput.WriteTo(fileStream);
            fileStream.Close();
        }
    }
}

适用于