问VSCode:打开解密，保存加密

EN

import * as vscode from 'vscode';
import * as path from 'path';
let steveChannel: vscode.OutputChannel | undefined;
let lastOpenFile = '' ;

// ----------------------------------- activate -----------------------------------
export function activate(context: vscode.ExtensionContext)
{
    steveChannel_writeLine(`activate`);

    vscode.window.onDidChangeActiveTextEditor((editor) =>
    {
        // text editor has been changed to a newly opened text file.
        if ( lastOpenFile == editor?.document.fileName )
        {
            let document = editor.document;
            const doc_text = editor.document.getText();
            const uc_text = doc_text.toUpperCase();

            // update contents of text editor to uppercase text.
            editor.edit(editBuilder =>
            {
                const range = doc_entireDocRange(document) ;
                editBuilder.replace( range, uc_text);
            });
        }
    });

    vscode.workspace.onDidOpenTextDocument((d) =>
    {
        const ext = path.extname(d.fileName) ;
        if ( ext == '.txt')
        {
            steveChannel_writeLine(`file opened ${d.fileName}`);

            // save name of most recently opened .txt file.
            // Use in change text editor event to detect when the text editor
            // contains the contents of a newly opened text file.
            lastOpenFile = d.fileName ;
        }
    });

    vscode.workspace.onDidSaveTextDocument((d) =>
    {
        const ext = path.extname(d.fileName);
        if (ext == '.txt')
        {
            steveChannel_writeLine(`file saved ${d.fileName}`);
        }
    });
}

// ---------------------------------- deactivate ----------------------------------
// this method is called when your extension is deactivated
export function deactivate() {}

// ---------------------------- steveChannel_writeLine ----------------------------
function steveChannel_writeLine(line: string)
{
    if (!steveChannel)
    {
        steveChannel = vscode.window.createOutputChannel('steve');
    }
    steveChannel.appendLine(line);
}

// ----------------------------- doc_entireDocRange -----------------------------
function doc_entireDocRange( doc: vscode.TextDocument )
{
    let invalidRange = new vscode.Range(0, 0, doc.lineCount /*intentionally missing the '-1' */, 0);
    let docRange = doc.validateRange(invalidRange);
    return docRange ;
}