ShowModal在FireMonkey移动应用程序对话框

This is the only code that changes between the first and second code snippets:

 dlg.ShowModal(procedure(ModalResult: TModalResult)

    begin

      if ModalResult = mrOK then

      // if OK was pressed and an item is selected, pick it

      if dlg.ListBox1.ItemIndex >= 0 then

        edit1.Text := dlg.ListBox1.Items [dlg.ListBox1.ItemIndex];

      dlg.DisposeOf;

    end);

 dlg.ShowModal(procedure(ModalResult: TModalResult)

    begin

      if ModalResult = mrOK then

      // if OK was pressed and an item is selected, pick it

      if dlg.ListBox1.ItemIndex >= 0 then

        edit1.Text := dlg.ListBox1.Items [dlg.ListBox1.ItemIndex];

      dlg.DisposeOf;

    end);

第一个代码片段：典型的代码调用的ShowModal

procedure THeaderFooterForm.btnPickClick(Sender: TObject);

var

  dlg: TForm1;

begin

  dlg := TForm1.Create(nil);

  try

    // select current value, if avaialble in the list

    dlg.ListBox1.ItemIndex := dlg.ListBox1.Items.IndexOf(edit1.Text);

 

    if dlg.ShowModal = mrOK then

      // if OK was pressed and an item is selected, pick it

      if dlg.ListBox1.ItemIndex >= 0 then

        edit1.Text := dlg.ListBox1.Items [dlg.ListBox1.ItemIndex];

  finally

    dlg.Free;

  end;

 

end;

procedure THeaderFooterForm.btnPickClick(Sender: TObject);

var

  dlg: TForm1;

begin

  dlg := TForm1.Create(nil);

  try

    // select current value, if avaialble in the list

    dlg.ListBox1.ItemIndex := dlg.ListBox1.Items.IndexOf(edit1.Text);

 

    if dlg.ShowModal = mrOK then

      // if OK was pressed and an item is selected, pick it

      if dlg.ListBox1.ItemIndex >= 0 then

        edit1.Text := dlg.ListBox1.Items [dlg.ListBox1.ItemIndex];

  finally

    dlg.Free;

  end;

 

end;

 

伪代码典型的ShowModal代码片段解读

这里是一个描述每个此过程的一部分：

声明局部变量

dlg: TForm1;

创建表格的形式和初始化成员

dlg := TForm1.Create(nil);

        dlg.ListBox1.ItemIndex := dlg.ListBox1.Items.IndexOf(edit1.Text);

显示的形式模态

if dlg.ShowModal = mrOK then

检查用户的结果和处理数据

if dlg.ListBox1.ItemIndex >= 0 then

      edit1.Text := dlg.ListBox1.Items [dlg.ListBox1.ItemIndex];

 释放表单 dlg.Free;

声明局部变量

dlg: TForm1;

创建表格的形式和初始化成员

dlg := TForm1.Create(nil);

        dlg.ListBox1.ItemIndex := dlg.ListBox1.Items.IndexOf(edit1.Text);

显示的形式模态

if dlg.ShowModal = mrOK then

检查用户的结果和处理数据

if dlg.ListBox1.ItemIndex >= 0 then

      edit1.Text := dlg.ListBox1.Items [dlg.ListBox1.ItemIndex];

 释放表单 dlg.Free;

第二个代码片段：作为一个匿名的方式在所有平台上调用的ShowModal

随着移动平台，你应该改变这种代码，悦目，让所有支持的目标平台上工作的ShowModal。

procedure THeaderFooterForm.btnPickClick(Sender: TObject);

var

  dlg: TForm1;

begin

  dlg := TForm1.Create(nil);

  // select current value, if available in the list

  dlg.ListBox1.ItemIndex := dlg.ListBox1.Items.IndexOf(edit1.Text);

 

  dlg.ShowModal(procedure(ModalResult: TModalResult)

    begin

      if ModalResult = mrOK then

      // if OK was pressed and an item is selected, pick it

      if dlg.ListBox1.ItemIndex >= 0 then

        edit1.Text := dlg.ListBox1.Items [dlg.ListBox1.ItemIndex];

      dlg.DisposeOf;

    end);

 

end;

procedure THeaderFooterForm.btnPickClick(Sender: TObject);

var

  dlg: TForm1;

begin

  dlg := TForm1.Create(nil);

  // select current value, if available in the list

  dlg.ListBox1.ItemIndex := dlg.ListBox1.Items.IndexOf(edit1.Text);

 

  dlg.ShowModal(procedure(ModalResult: TModalResult)

    begin

      if ModalResult = mrOK then

      // if OK was pressed and an item is selected, pick it

      if dlg.ListBox1.ItemIndex >= 0 then

        edit1.Text := dlg.ListBox1.Items [dlg.ListBox1.ItemIndex];

      dlg.DisposeOf;

    end);

 

end;

 

匿名方法的ShowModal代码片段的伪代码解读

这里是一个描述发生了什么（做同样的事情，第一个代码段）在第二个代码片段：

 

Declare local variables

    dlg: TForm1;



Create form and initialize member in the form

    dlg := TForm1.Create(nil);

        dlg.ListBox1.ItemIndex := dlg.ListBox1.Items.IndexOf(edit1.Text);



Show the form modal

      dlg.ShowModal(procedure(ModalResult: TModalResult)



Check the user's result and process the data

    if ModalResult = mrOK then

      if dlg.ListBox1.ItemIndex >= 0 then

        edit1.Text := dlg.ListBox1.Items [dlg.ListBox1.ItemIndex];



Free the form

          dlg.DisposeOf;

Declare local variables

    dlg: TForm1;



Create form and initialize member in the form

    dlg := TForm1.Create(nil);

        dlg.ListBox1.ItemIndex := dlg.ListBox1.Items.IndexOf(edit1.Text);



Show the form modal

      dlg.ShowModal(procedure(ModalResult: TModalResult)



Check the user's result and process the data

    if ModalResult = mrOK then

      if dlg.ListBox1.ItemIndex >= 0 then

        edit1.Text := dlg.ListBox1.Items [dlg.ListBox1.ItemIndex];



Free the form

          dlg.DisposeOf;