JS实现 解禁页面 部分 被禁止复制粘贴 的 表单元素

//屏蔽右键菜单
document.oncontextmenu = function (event) { if (window.event) {
        event = window.event;
    } try { var the = event.srcElement; if (!( ( the.tagName == "INPUT" && the.type.toLowerCase() == "text" ) || the.tagName == "TEXTAREA" )) { return false;
        } return true;
    } catch (e) { return false;
    }
} 
//屏蔽粘贴 
document.onpaste = function (event) { if (window.event) {
        event = window.event;
    } try { var the = event.srcElement; if (!( ( the.tagName == "INPUT" && the.type.toLowerCase() == "text" ) || the.tagName == "TEXTAREA" )) { return false;
        } return true;
    } catch (e) { return false;
    }
} 
//屏蔽复制 
document.oncopy = function (event) { if (window.event) {
        event = window.event;
    } try { var the = event.srcElement; if (!( ( the.tagName == "INPUT" && the.type.toLowerCase() == "text" ) || the.tagName == "TEXTAREA" )) { return false;
        } return true;
    } catch (e) { return false;
    }
} 
//屏蔽剪切 
document.oncut = function (event) { if (window.event) {
        event = window.event;
    } try { var the = event.srcElement; if (!( ( the.tagName == "INPUT" && the.type.toLowerCase() == "text" ) || the.tagName == "TEXTAREA" )) { return false;
        } return true;
    } catch (e) { return false;
    }
} 
//屏蔽选择 
document.onselectstart = function (event) { if (window.event) {
        event = window.event;
    } try { var the = event.srcElement; if (!( ( the.tagName == "INPUT" && the.type.toLowerCase() == "text" ) || the.tagName == "TEXTAREA" )) { return false;
        } return true;
    } catch (e) { return false;
    }
}