js 怎么向app 传图片

// 假设App注册了myapp://协议
function openAppWithImage(imageUrl) {
    var appUrl = 'myapp://showImage?url=' + encodeURIComponent(imageUrl);
    window.location = appUrl;
}

// 调用函数
openAppWithImage('https://example.com/path/to/image.jpg');

function getImageBase64(url, callback) {
    var xhr = new XMLHttpRequest();
    xhr.open('GET', url, true);
    xhr.responseType = 'blob';
    xhr.onload = function() {
        if (this.status == 200) {
            var reader = new FileReader();
            reader.onloadend = function() {
                callback(reader.result);
            }
            reader.readAsDataURL(this.response);
        }
    };
    xhr.send();
}

function openAppWithBase64Image(base64Data) {
    var appUrl = 'myapp://showImage?data=' + encodeURIComponent(base64Data);
    window.location = appUrl;
}

// 使用示例
getImageBase64('https://example.com/path/to/image.jpg', function(base64Data) {
    openAppWithBase64Image(base64Data);
});

// 前端上传图片到服务器
function uploadImage(file, callback) {
    var formData = new FormData();
    formData.append('image', file);

    fetch('https://yourserver.com/upload', {
        method: 'POST',
        body: formData
    }).then(response => response.json())
      .then(data => callback(data.imageUrl))
      .catch(error => console.error('Error:', error));
}

// 调用上传函数
var input = document.querySelector('input[type="file"]');
input.addEventListener('change', function(event) {
    var file = event.target.files[0];
    uploadImage(file, function(imageUrl) {
        // 通知App下载图片
        openAppWithImage(imageUrl);
    });
});