bootstarp 模态框大小尺寸的控制

默认：

<!-- 模态框（Modal） -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
    <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
                <h4 class="modal-title" id="myModalLabel">模态框（Modal）标题</h4>
            </div>
            <div class="modal-body">按下 ESC 按钮退出。</div>
            <div class="modal-footer">
                <button type="button" class="btn btn-default" data-dismiss="modal">关闭</button>
                <button type="button" class="btn btn-primary">提交更改</button>
            </div>
        </div><!-- /.modal-content -->
    </div><!-- /.modal-dialog -->
</div>
<!-- /.modal -->
<script>
$(function() {
    $('#myModal').modal({
        keyboard: true
    })
});
</script>

　　效果如图：

  变大：

<!-- 模态框（Modal） -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
    <div class="modal-dialog modal-lg">
        <div class="modal-content">
            <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
                <h4 class="modal-title" id="myModalLabel">模态框（Modal）标题</h4>
            </div>
            <div class="modal-body">按下 ESC 按钮退出。</div>
            <div class="modal-footer">
                <button type="button" class="btn btn-default" data-dismiss="modal">关闭</button>
                <button type="button" class="btn btn-primary">提交更改</button>
            </div>
        </div><!-- /.modal-content -->
    </div><!-- /.modal-dialog -->
</div>
<!-- /.modal -->
<script>
$(function() {
    $('#myModal').modal({
        keyboard: true
    })
});
</script>

　　效果如图：

 变小：

<!-- 模态框（Modal） -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
    <div class="modal-dialog modal-sm">
        <div class="modal-content">
            <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
                <h4 class="modal-title" id="myModalLabel">模态框（Modal）标题</h4>
            </div>
            <div class="modal-body">按下 ESC 按钮退出。</div>
            <div class="modal-footer">
                <button type="button" class="btn btn-default" data-dismiss="modal">关闭</button>
                <button type="button" class="btn btn-primary">提交更改</button>
            </div>
        </div><!-- /.modal-content -->
    </div><!-- /.modal-dialog -->
</div>
<!-- /.modal -->
<script>
$(function() {
    $('#myModal').modal({
        keyboard: true
    })
});
</script>

　　效果如图：

  当然  也可以调节<div>的宽度 width 高度 height

<div class="modal-content" style="800px; height:500px;">

　　效果如图：