Delphi | 易学教程

Error “Could not load SSL library” on Android with TidHTTP

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问题 I'm trying to download a file with TIdHTTP.Get in Delphi Seattle. It's an app for android and all my attempts fails. All i get it's the same error "Could not load SSL library". This is the procedure: procedure TfrmMain.DownloadPicture(const AURL: string); var MeS: TMemoryStream; cidSSL: TIdSSLIOHandlerSocketOpenSSL; cidHTTP: TIdHTTP; begin cidHTTP:= TIdHTTP.Create(nil); cidSSL:= TIdSSLIOHandlerSocketOpenSSL.Create(nil); Mes := TMemoryStream.Create; try cidHTTP.ReadTimeout := 30000; cidHTTP

delphi常用数据类型

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一：简单类型包括：整形、字符型、布尔型、枚举、子界类型、实型。除实型以外，都是有序类型，即每个值在值域中都有一个序数。 1.1 整型包括 Integer、Cardinal 、Shortint、Smallint、Longint、 Int64、Byte、 Word、Longword 以及UInt64 共 10种具体类型。 1.2 字符类型包括 ansiChar 和 WideChar , ansiChar使用一个字节表示一个字符，WideChar则用两个字节表示一个字符。二者之间不能相互赋值。 1.3 布尔型用于判断真假，只有 true和false 两种值。 delphi内置4中布尔类型：Boolean/ByteBool/WordBoolLongBool，内存中分别占1、1、2、4个字节。 1.4 枚举类型 type 名 = (标识符1，标识符2，标识符3.。。。); 1.5 子界类型 type 子界类型名 = 下界..上界 type TSomeInts = 1…250; //子界类型含有1~250个整数 TIntSet = set of TSomeInts; //集合TIntSet是子界类型TSomeInts的一个有限子集 1.6 实型二：结构类型集合、数组、记录,文件*、类*、类引用*、接口* 2.1 集合类型 type set1 = set of 有序值得集合 type

initializing private var creates AccessViolation

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问题 Comming from a C# background I'm trying to learn Delphi. I encounter an Access violation when in my form I press a button that creates a TLight instance. Wherever I try to access my private FState I get an access violation. What am I missing? unit Light; interface uses sysUtils; type TLightStates = (Red, Orange, Green); type TLight = class private Fstate : TLightStates; published Constructor Create(); overload; procedure SetState(const Value: TLightStates); Property State : TLightStates read

Delphi - Access violation when try to overwrite an instruction with DLL Injection

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问题 Good morning. I'm trying to learn about DLL injection, so I've wrote a little software, that just gets a String, compares with StrCmp() and if the input was equal "Winner", the software gives a Good boy message, with the porpouse of learn DLL injection. So I write a DLL that loads a Form when inject, the porpouse is using the DLL injection, to modify the Instruction of comparison( JNZ(74) to JMP(EB)), and make the software, accept any string. My DLL code is: library Project2; uses SysUtils,

Delphi - OmniThreadLibrary Parallel.ForEach with Records

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问题 I am running Delphi XE2 and trying to get familiar with the OmniThreadLibrary, I have 3.03b installed. I have been looking at the Parallel.ForEach examples and am not sure of what's going on in the background (this may well be obvious later - sorry). Any information you can offer to help me better understand how to achieve my goal will be much appreciated. Suppose I have some record that is just a container for 2 related values, a and b. I then want to run a parallel loop that returns an

Delphi - OmniThreadLibrary Parallel.ForEach with Records

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Registering a Firebird Blob Filter using FireDac (Delphi)

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问题 Having used Firebird SQL and Delphi for years I have always registered my own Blob Filters using FBPlus from Devrace. As Delphi now ships with FireDac I am hoping to shift over to this technology, removing the requirement of third party data access components. Has anyone any experience with registering Firebird SQL Blob filters in FireDac? Though I can simply access the fields as binary data and run through the routines for decompression etc, I would rather have access on a field level

FM Mobile Destroy Form

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问题 How i can destroy form, I want: creatr Form1(start application), create Form 2, destroy Form1, working with form2, then create form 3, destroy form2. but I not know how to destroy form. If i call: procedure TFPressStartScreen.btn1Click(Sender: TObject); begin MainScreen.FMainScreen := MainScreen.TFMainScreen.Create(Application); MainScreen.FMainScreen.Show; DisposeOf; end; FPressStartScreen - 1 form, FMainScreen - 2 form, i create 2 form and need destroy 1. but i get access violation. 来源：

Button placed on selected TListItem in most cases doesn't receive click

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问题 I have a Firemonkey TListBox in an Android app and in OnPaint I place 3 buttons on the selected TListBoxItem. They are being displayed and all have a OnClick event assigned. But when clicking them this event usually does not fire. Only seldom I get the button clicked. I guess the TListBox already received the click and declared it as handled. Is there any way otherwise? Can I register a tap in the form itsself and determine from the position of the tap which of the buttons must have been

how connect excel 2007 for delphi7 [closed]

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问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 8 years ago . I can connect with paradox base, oracle etc. Now I want to work with excel how can I do it ? 回答1: With ADO, you can set the connectionstring like this: ConnectionString := 'Provider=Microsoft.Jet.OLEDB.4.0;Data