JS_0052：JS 禁止触摸屏双指放大，双指缩放。

// 禁用缩放
function addMeta() {
    $('head').append('<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no" />');
}
setTimeout(addMeta, 3000);

// 禁用双指放大
document.documentElement.addEventListener('touchstart', function (event) {
    if (event.touches.length > 1) {
        event.preventDefault();
    }
}, {
    passive: false
});

// 禁用双击放大
var lastTouchEnd = 0;
document.documentElement.addEventListener('touchend', function (event) {
    var now = Date.now();
    if (now - lastTouchEnd <= 300) {
        event.preventDefault();
    }
    lastTouchEnd = now;
}, {
    passive: false
});