本文主要是介绍delphi chrome cef3 控件学习笔记 (三),希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
Delphi与js的交互问题:
一、执行简单的JS
上一篇已经讲过:
chrm1.browser.MainFrame.ExecuteJavaScript('alert("abc");','about:blank',0);
chrm1.browser.MainFrame.ExecuteJavaScript('function aaa(){alert("abc");}aaa();','about:blank',0);
二、注入自定义的JS
首先必须在网页加载完成之后,才可以执行,不能为空页面!
str_js := 'var oScript = document.createElement( "script" );oScript.id = "sid";alert(oScript.id);';
chrm1.browser.MainFrame.ExecuteJavaScript(str_js,'about:blank',0);
三、delphi与JS交互(通过ceflib实现)
Cef3的Demo里面,有一个cefclient的例子,可以看下,关键代码:
TExtension = class(TCefv8HandlerOwn)
private
FTestParam: ustring;
protected
function Execute(const name: ustring; const obj: ICefv8Value;
const arguments: TCefv8ValueArray; var retval: ICefv8Value;
var exception: ustring): Boolean; override; //重写Execute事件
end;
//通过不同的name,执行不同的动作
function TExtension.Execute(const name: ustring; const obj: ICefv8Value;
const arguments: TCefv8ValueArray; var retval: ICefv8Value;
var exception: ustring): Boolean;
begin
if(name = 'SetTestParam') then
begin
// Handle the SetTestParam native function by saving the string argument
// into the local member.
if (Length(arguments) <> 1) or (not arguments[0].IsString) then
begin
Result := false;
Exit;
end;
FTestParam := arguments[0].GetStringValue; //多个参数arguments[i].GetStringValue 依次类推
Result := true;
end
else if(name = 'GetTestParam') then
begin
// Handle the GetTestParam native function by returning the local member
// value.
retval := TCefv8ValueRef.CreateString(Ftestparam);
Result := true;
end
else if (name = 'GetTestObject') then
begin
// Handle the GetTestObject native function by creating and returning a
// new V8 object.
retval := TCefv8ValueRef.CreateObject(nil);
// Add a string parameter to the new V8 object.
retval.SetValueByKey('param', TCefv8ValueRef.CreateString(
'Retrieving a parameter on a native object succeeded.'));
// Add a function to the new V8 object.
retval.SetValueByKey('GetMessage',
TCefv8ValueRef.CreateFunction('GetMessage', Self));
Result := true;
end
else if(name = 'GetMessage') then
begin
// Handle the GetMessage object function by returning a string.
retval := TCefv8ValueRef.CreateString(
'Calling a function on a native object succeeded.');
Result := true;
end else
Result := false;
end;
{ 注册JS扩展 }
procedure RegisterExtension;
var
Code: string;
begin
Code :=
'var cef;if(!cef)cef={};if(!cef.taobao)cef.taobao={};(function(){cef.taobao.test_object=function(){native function GetTestObject();return GetTestObject();};})();';
if Code <> '' then
try
CefRegisterExtension('example/v8',Code,TExtension.Create as ICefv8Handler);
except
end;
end;
在FormCreate中注册类:
RegisterExtension;
调用实例:
chrm1.browser.MainFrame.ExecuteJavaScript('alert("abc");','about:blank',0);
str_temp := 'function aaa(){var CefObj = new cef.taobao.test_object;'+ //先new一个实例对象
'CefObj.SetTestParam("abc");var b=CefObj.GetTestParam();alert(b);'+ //设置、获取、输出参数
'}aaa();';
chrm1.Browser.MainFrame.ExecuteJavaScript(str_temp,'about:blank',0);
如果要实现多个参数,可以定义个数组替代FTestParam
private
FTestParam : ustring;
ArrayParam : array of ustring; //多个参数
关键代码:
if(name = 'SetTestParam') then
begin
// 原来一个参数的情况
// if (Length(arguments) <> 1) or (not arguments[0].IsString) then
// begin
// Result := false;
// Exit;
// end;
// FTestParam := arguments[0].GetStringValue;
// 原来一个参数的情况
SetLength(ArrayParam,Length(arguments));
for i := 0 to Length(arguments) - 1 do
begin
ArrayParam[i] := arguments[i].GetStringValue;
if s='' then
s := ArrayParam[i]
else
s := s+','+ArrayParam[i];
end;
FTestParam := s;
end
else if(name = 'GetTestParam') then
begin
// 原来一个参数的情况
// retval := TCefv8ValueRef.CreateString(FTestParam);
// 原来一个参数的情况
for i := 0 to Length(ArrayParam) - 1 do
begin
if s='' then
s := ArrayParam[i]
else
s := s+','+ArrayParam[i];
end;
retval := TCefv8ValueRef.CreateString(FTestParam);
end;
这样调用GetTestParam返回的还是一个字符串,多个参数用逗号隔开了而已,可以对其再进行改写即可;
这篇关于delphi chrome cef3 控件学习笔记 (三)的文章就介绍到这儿,希望我们推荐的文章对编程师们有所帮助!