attr disabled does not work code example

Example 1: disabled attribute is not working in html

try to use disabled="disabled":

<input type="text" id="txtEditAlternate" class="form-control" name="alternate" disabled="disabled" />

I hope it will work for you.

Example 2: attr.disabled not working in angular

css

.disabled-contenct {
  pointer-events: none;
  opacity: 0.4;
}

html
<div [class.disabled-contenct]="!isDisabledContent"></div>