当他们期望 NativeUInt 时，我应该如何将负值传递给 SendMessage 和 Perform? [英] How should I pass negative values to SendMessage and Perform when they expect a NativeUInt?

问题描述

假设你有这样的代码:

Result.X := ACustomMemo.Perform(EM_LINEFROMCHAR, -1, 0); 

Windows API 声称-1"是一个有效值，使其返回活动行.

The Windows API claims "-1" is a valid value that makes it it return the active line.

但是，Delphi 将其定义为 NaiveUInt 并在我尝试传递 -1 时抱怨.

However, Delphi has this defined as NaiveUInt and complains if I try to pass -1.

最干净的解决方案是什么?铸造?

What is the cleanest solution to this? Casting?

推荐答案

将 -1 值强制转换为 WPARAM 是处理这种情况的正确方法.

Casting the -1 value to WPARAM is the proper way to handle this case.

 Result.X := ACustomMemo.Perform(EM_LINEFROMCHAR, WPARAM(-1), LPARAM(0));

顺便说一句，WPARAM 类型的 delphi NativeUint 定义是正确的，因为是 x86 上的无符号 32 位和 x64 上的无符号 64 位.

btw, the delphi NativeUint definition for the WPARAM type is correct, because is a unsigned 32-bit on x86 and unsigned 64-bit on x64.

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