js 獲取窗體寬度和高度 JavaScript

 

<script type="text/javascript">
	$(document).ready(function(){
		var winWidth = 0;
		var winHeight = 0;
		findDimensions();
		function findDimensions() // 函數：獲取尺寸
		{
			// 獲取窗口寬度
			if (window.innerWidth)
			winWidth = window.innerWidth;
			else if ((document.body) && (document.body.clientWidth))
			winWidth = document.body.clientWidth;
			// 獲取窗口高度
			if (window.innerHeight)
			winHeight = window.innerHeight;
			else if ((document.body) && (document.body.clientHeight))
			winHeight = document.body.clientHeight;
			// 通過深入 Document 內部對 body 進行檢測，獲取窗口大小
			if (document.documentElement && document.documentElement.clientHeight && document.documentElement.clientWidth)
			{
			winHeight = document.documentElement.clientHeight;
			winWidth = document.documentElement.clientWidth;
			}
		}
		$("form").before('<div style="height: '+winHeight*0.2+'px"></div>');
		
	});
</script>