I thought I would some extension methods I have been using for a little while now for Linq to Xml. When loading and retrieving the attribute values from XML nodes via Linq there is a bit of code to write to make sure the attribute exists and that the value is a valid data type. Rather than having a bunch of code to do this I simply wrote some extensions that operate on an XElement and are targeted at returning the value of an XAttribute.
Usage:
var element = XElement.Parse("<value x="50.5"/>");var value = element.GetDoubleValue("x");.csharpcode, .csharpcode pre{ font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/}.csharpcode pre { margin: 0em; }.csharpcode .rem { color: #008000; }.csharpcode .kwrd { color: #0000ff; }.csharpcode .str { color: #006080; }.csharpcode .op { color: #0000c0; }.csharpcode .preproc { color: #cc6633; }.csharpcode .asp { background-color: #ffff00; }.csharpcode .html { color: #800000; }.csharpcode .attr { color: #ff0000; }.csharpcode .alt{ background-color: #f4f4f4; width: 100%; margin: 0em;}.csharpcode .lnum { color: #606060; }.csharpcode, .csharpcode pre{ font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/}.csharpcode pre { margin: 0em; }.csharpcode .rem { color: #008000; }.csharpcode .kwrd { color: #0000ff; }.csharpcode .str { color: #006080; }.csharpcode .op { color: #0000c0; }.csharpcode .preproc { color: #cc6633; }.csharpcode .asp { background-color: #ffff00; }.csharpcode .html { color: #800000; }.csharpcode .attr { color: #ff0000; }.csharpcode .alt{ background-color: #f4f4f4; width: 100%; margin: 0em;}.csharpcode .lnum { color: #606060; }
Anyway, here is the class for the extensions:
1: using System;
2: using System.Xml.Linq;
3: 4: namespace System.Xml.Linq
5: { 6: public static class XLinqEx
7: { 8: /// <summary>
9: /// Gets a short value for the specified attribute.
10: /// </summary>
11: /// <param name="element">The element to parse.</param>
12: /// <param name="attributeName">The XName of the attribute to parse.</param>
13: /// <returns>A short value representation of the attribute value.</returns>
14: public static short GetInt16Value(this XElement element, XName attributeName)
15: { 16: var attribute = element.Attribute(attributeName); 17: if (attribute == null)
18: return 0;
19: 20: short result = 0;
21: Int16.TryParse(attribute.Value, out result);
22: return result;
23: } 24: 25: /// <summary>
26: /// Gets an int value for the specified attribute.
27: /// </summary>
28: /// <param name="element">The element to parse.</param>
29: /// <param name="attributeName">The XName of the attribute to parse.</param>
30: /// <returns>An int value representation of the attribute value.</returns>
31: public static int GetInt32Value(this XElement element, XName attributeName)
32: { 33: var attribute = element.Attribute(attributeName); 34: if (attribute == null)
35: return 0;
36: 37: int result = 0;
38: Int32.TryParse(attribute.Value, out result);
39: return result;
40: } 41: 42: /// <summary>
43: /// Gets a long value for the specified attribute.
44: /// </summary>
45: /// <param name="element">The element to parse.</param>
46: /// <param name="attributeName">The XName of the attribute to parse.</param>
47: /// <returns>A long value representation of the attribute value.</returns>
48: public static long GetInt64Value(this XElement element, XName attributeName)
49: { 50: var attribute = element.Attribute(attributeName); 51: if (attribute == null)
52: return 0;
53: 54: long result = 0;
55: Int64.TryParse(attribute.Value, out result);
56: return result;
57: } 58: 59: /// <summary>
60: /// Gets a double value for the specified attribute.
61: /// </summary>
62: /// <param name="element">The element to parse.</param>
63: /// <param name="attributeName">The XName of the attribute to parse.</param>
64: /// <returns>A double value representation of the attribute value.</returns>
65: public static double GetDoubleValue(this XElement element, XName attributeName)
66: { 67: var attribute = element.Attribute(attributeName); 68: if (attribute == null)
69: return 0;
70: 71: double result = 0;
72: Double.TryParse(attribute.Value, out result);
73: return result;
74: } 75: 76: /// <summary>
77: /// Gets a bool value for the specified attribute.
78: /// </summary>
79: /// <param name="element">The element to parse.</param>
80: /// <param name="attributeName">The XName of the attribute to parse.</param>
81: /// <returns>A bool value representation of the attribute value.</returns>
82: public static bool GetBooleanValue(this XElement element, XName attributeName)
83: { 84: var attribute = element.Attribute(attributeName); 85: if (attribute == null)
86: return false;
87: 88: bool result = false;
89: Boolean.TryParse(attribute.Value, out result);
90: return result;
91: } 92: 93: /// <summary>
94: /// Gets a string value for the specified attribute.
95: /// </summary>
96: /// <param name="element">The element to parse.</param>
97: /// <param name="attributeName">The XName of the attribute to parse.</param>
98: /// <returns>A string value representation of the attribute value.</returns>
99: public static string GetStringValue(this XElement element, XName attributeName)
100: { 101: var attribute = element.Attribute(attributeName); 102: if (attribute == null)
103: return String.Empty;
104: 105: return attribute.Value;
106: } 107: 108: /// <summary>
109: /// Gets a byte array from the base 64 encoded value of the current element.
110: /// </summary>
111: /// <param name="element">The element to parse.</param>
112: /// <returns>A byte array of the base 64 encoded element value.</returns>
113: public static byte[] GetByteArray(this XElement element)
114: { 115: var value = element.Value;
116: if (!String.IsNullOrEmpty(value))
117: { 118: return Convert.FromBase64String(value);
119: } 120: return null;
121: } 122: } 123: }1/19/2010
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1/18/2010