bitmap | 易学教程

How to draw the bitmap icon on title bar when Windows Aero theme is enabled

阅读更多关于 How to draw the bitmap icon on title bar when Windows Aero theme is enabled

问题 I'm developing a MFC application ( DWM library is not available ). I want to draw a bitmap functioning as a button on the title bar. However, the bitmap won't present when the Aero theme is enabled in Windows 7 (There are no problem when I disable the Aero theme). But my application still reactable by clicking on the position of the bitmap. Does anyone can teach me how to solve this problem? Thanks 回答1: Drawing custom data into the frame area with DWM is described on MSDN, also the hit

How do I create a dynamic mouse cursor .NET without using interop?

阅读更多关于 How do I create a dynamic mouse cursor .NET without using interop?

问题 I have an application which I'm interested in eventually porting to mono so I'm trying to avoid using p/invoke's to accomplish this task. I would like to load a cursor dynamically, as in I have a Bitmap that is generated on the fly in the application. From what I can tell the safest way to do it without using p/invoke's is to create a .cur file which I can then load to a memory stream and use the Cursor(Stream) constructor. However I have no idea how to create a .cur file. I found this

Bitmap.SetPixel(x,y, Color) too slow

阅读更多关于 Bitmap.SetPixel(x,y, Color) too slow

问题 So currently I'm creating a 1000x1000 bitmap and it's spending about .3 seconds simply calling the Bitmap.SetPixel() function. I'm actually only drawing probably 50% of the pixels so it's more like 500,000 call to setpixel. While that does seem like a lot of calls, OTOH video games are do alot more and push many many more pixels (some of them procedureally generated). Obviously Bitmap.SetPixel isn't optimized for speed, but if I needed to update a bitmap 20-30 times a second to get decent

初冬太冷？圣诞无处可去？那跟我一起来学Android吧

阅读更多关于初冬太冷？圣诞无处可去？那跟我一起来学Android吧

又到年底了，每到这个时候，我们都会慢慢反思，这一年都做了什么？有什么进步？年初的计划都实现了吗？明年年初有跳槽的底气了吗？况且今年的互联网环境太差，需要自己有足够的知识储备，才能够应对这凌冽的寒风。本文主要是整理了中高级安卓需要会的（或者说面试被频繁问到的内容），主要作为参考大纲，之后会陆续更新每个详细部分，供大家参考，互相学习。面试板块(PDF版如下)： BAT面试合集（Binder，组件化插件化，热修复，AOP，QQ换肤，虚拟机，https，线程池原理，音视频原理）算法合集（Hash,KMP 等）中小厂面试合集（内存泄漏，Handler，View，MVC.MVP.MVVM，）大厂相关更新技术（Glide,数据库，NDK）面试小知识（java小知识）设计模式（设计模式原则和分类）数据结构（数据结构等等）网络编程（三次握手和四次握手，Volley，OKHttps,Retrofit）源码解析(属性动画实现原理等）多线程解析（线程同步，进程线程）性能优化（Webview,内存泄漏和内存溢出等）（顺手留下GitHub链接，需要获取相关面试或者面试宝典核心笔记PDF等内容的可以自己去找） https://github.com/xiangjiana/Android-MS 一丶设计模式与使用场景 (如）建造者模式：将一个复杂对象的构建与它的表示分离

WPF, C#: Draw a line onto existing bitmap in image control

阅读更多关于 WPF, C#: Draw a line onto existing bitmap in image control

问题 I have a bitmap image in an image control I need to draw a red line on the bitmap each time I click with the mouse onto it, at the place where I clicked the mouse. I first thought of creating a Line object, but found out, that I cannot add the Line. I would need a canvas. But if I put my image in a canvas, my bitmap does not stretch over the whole canvas (I found out, that the coordinates of the bitmap determine the place on the canvas, so my bitmap is wrongly displayed.) Then I tried using

WPF, C#: Draw a line onto existing bitmap in image control

阅读更多关于 WPF, C#: Draw a line onto existing bitmap in image control

Android Convert view to BitMap

阅读更多关于 Android Convert view to BitMap

问题 I'm trying to convert a view to bitmap but I lose the black color. I'm converting like this: Bitmap returnedBitmap = Bitmap.createBitmap(view.getWidth(),view.getHeight(), Bitmap.Config.ARGB_8888); Example How can i convert to bitmap so the black of the percentage value is not lost? Thanks, Regards 回答1: Hi you can use this method to convert View to Bitmap private Bitmap createBitmapFromView(Context context, View view) { DisplayMetrics displayMetrics = new DisplayMetrics(); ((Activity) context)

Load BitmapImage into WriteableBitmap but no method existing

阅读更多关于 Load BitmapImage into WriteableBitmap but no method existing

问题 The constructor of WriteableBitmap class with Windows 8 only takes two arguments: the height and the width of this object. Meanwhile with Silverlight it accepts a BitmapImage object as argument. (Verified on MSDN : WriteableBitmap.WriteableBitmap constructor) I would like to load this BitmapImage because I'm trying to blur an image which already exists on my Assets folder. 回答1: Thanks for your help, I succeed to blur my image. Here is the sample in order to link the BitmapImage into the

Get bitmap info from MPEG-2 Program / Transport Stream?

阅读更多关于 Get bitmap info from MPEG-2 Program / Transport Stream?

问题 In order to render a DirectShow graph in my WPF application, I use a sample grabber to write a bitmap to memory, and read it elsewhere in code. This may seem as a wierd solution, but seems to be the only way to get a WPF brush out of it. The following code gives me the information I need about the bitmap: AMMediaType mt = grabber.GetConnectedMediaType(); VideoInfoHeader header = (VideoInfoHeader)Marshal.PtrToStructure(mt.formatPtr, typeof VideoInfoHeader); header.BmiHeader // ... Now, header

Creating 8bpp bitmap with GDI and saving it as a file

阅读更多关于 Creating 8bpp bitmap with GDI and saving it as a file

问题 I have a perfectly working code that creates 32bpp bitmap and I need to change it so that 8bpp bitmap is created. Here's the piece of code that creates 32bpp bitmap, draws into it, then it creates a bitmap file and store it into the vector of bytes: // prepare bitmap: BYTE* bitmap_data = NULL; HDC hDC = GetDC(NULL); HDC memHDC = CreateCompatibleDC(hDC); BITMAPINFO bmi; memset(&bmi, 0, sizeof(BITMAPINFO)); bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER); bmi.bmiHeader.biWidth = desiredWidth; /