[Silverlight] hexadecimal color to argb and color to int32

Web users like to use a hexadecimal string to identify the color, such as "# f5f5f5". Naturally, this is represented by argb in Silverlight/WPF: "# fff5f5f5" (the first two identities are alpha, that is, transparency ). There is no problem in XAML, but what if we want to set the color in the code or read the relevant values from XML?

It is inevitable that an error will be reported. At least I don't know whether SL or WPF has published this converter. I can't do anything about it anyway.

Here is a code snippet that helps us convert a hexadecimal string into an argb color.

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public　static　Color　ToColor(this　string　colorName)　{ 　　　　if　(colorName.StartsWith("#")) 　　　　　　　　colorName　=　colorName.Replace("#",　string.Empty); 　　　　int　v　=　int.Parse(colorName,　System.Globalization.NumberStyles.HexNumber); 　　　　return　new　Color()　{ 　　　　　　　　A　=　Convert.ToByte((v　>>　24)　&　255), 　　　　　　　　R　=　Convert.ToByte((v　>>　16)　&　255), 　　　　　　　　G　=　Convert.ToByte((v　>>　8)　&　255), 　　　　　　　　B　=　Convert.ToByte((v　>>　0)　&　255) 　　　　}; }

 

Here I made the extension method, and then used it like this

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12	Rectangle　rectangle　=　new　Rectangle(); rectangle.Fill　=　new　SolidColorBrush("#FFF5F5F5".ToColor());

 

Naturally, no problem.

Color to int32

Here you may ask, what is the use of color to int? In fact, if you use some existing image libraries, they often express color as an int value. In this case, the argb value is represented by a 32-bit int in the order of its bytes rggbb. Here we can perform the following conversions:

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public　static　int　ToArgb(this　Color　color)　{ 　　　　int　argb　=　color.A　<<　24; 　　　　argb　+=　color.R　<<　16; 　　　　argb　+=　color.G　<<　8; 　　　　argb　+=　color.B; 　　　　return　argb; }

 

The following is a comprehensive application of the two methods:

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Rectangle　rectangle　=　new　Rectangle(); SolidColorBrush　scb　=　new　SolidColorBrush(); scb.Color　=　"#FFF5F5F5".ToColor(); rectangle.Fill　=　scb; MessageBox.Show(scb.Color.ToArgb().ToString());

 

Guess what the value of MessageBox show is?

OK, meeting :)