我正在使用JavaScript开发Windows 8应用程序.我需要获取给定目录中的所有图片(每张图片的路径).我该怎么做？
我有以下内容：
(function () {
"use strict";
var page = WinJS.UI.Pages.define("/html/scenario3.html",{
ready: function (element,options) {
document.getElementById("folder").addEventListener("click",pickFolder,false);
}
});
function pickFolder() {
// Clean scenario output
WinJS.log && WinJS.log("","sample","status");
// Verify that we are currently not snapped,or that we can
// unsnap to open the picker
var currentState = Windows.UI.ViewManagement.ApplicationView.value;
if (currentState === Windows.UI.ViewManagement.ApplicationViewState.snapped && !Windows.UI.ViewManagement.ApplicationView.tryUnsnap()) {
// Fail silently if we can't unsnap
return;
}
// Create the picker object and set options
var folderPicker = new Windows.Storage.Pickers.FolderPicker;
folderPicker.suggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.desktop;
// Users expect to have a filtered view of their folders depending on the scenario.
// For example,when choosing a documents folder,restrict the filetypes to documents for your application.
folderPicker.fileTypeFilter.replaceAll(["*"]);
//folderPicker.fileTypeFilter.replaceAll([".png",".jpg",".jpeg"]);
folderPicker.pickSingleFolderAsync().then(function (folder) {
if (folder) {
// Application now has read/write access to all contents in the picked folder (including sub-folder contents)
// Cache folder so the contents can be accessed at a later time
Windows.Storage.AccessCache.StorageApplicationPermissions.futureAccessList.addOrReplace("PickedFolderToken",folder);
var pictures = Windows.Storage.KnownFolders.folder;
pictures.getFilesAsync().done(function (images) {
console.log(images.length + " images found.");
WinJS.log && WinJS.log("Total Images: " + images.length,"status");
});
} else {
// The picker was dismissed with no selected file
WinJS.log && WinJS.log("Operation cancelled.","status");
}
});
}
})();
最佳答案
如果需要从图片库加载图片,首先需要检查项目的package.appxmanifest文件内的Capabilities选项卡中是否启用了此功能.
启用后,您可以使用以下内容引用此库：
// 'pictures' is a reference to our Pictures Library
var pictures = Windows.Storage.KnownFolders.picturesLibrary;
Microsoft决定任何超过50毫秒的操作都需要异步,因此要从这个库中获取图像,我们必须使用以下异步方法,并在解析promise时处理结果：
// Get a list of files ('images') within our Pictures Library
pictures.getFilesAsync().done(function( images ) {
console.log( images.length + " images found." );
});
从这里你可以迭代找到的图像,并根据你的喜好处理它们.
有关更多信息,请查看Window.Storage命名空间.
此外,您可能会发现File access sample也很有帮助.
更新
从您更新的代码我可以看到您允许用户选择他们选择的文件夹.有了这个,您需要设置fileTypeFiltering,然后在pickSingleFolderAsync promise解析后拉出图像：
// Prompt user to select a folder
var picker = Windows.Storage.Pickers.FolderPicker();
// Which file types will we be showing?
picker.fileTypeFilter.append(".jpg");
// Grab the selected folder,reference as 'folder'
picker.pickSingleFolderAsync().then(function (folder) {
// Get files within selected folder as 'files'
folder.getFilesAsync().then(function (files) {
// Output number of files found
console.log(files.length + " files found.");
});
});
