typeconverter

问题 The usercontrol that will use the type converter Public Class MYControl : Usercotrol { private ListItem _Language; [TypeConverter(typeof(LanguageEditor))] public ListItem Language { get { return _Language; } set { _Language= value; } } } The type to list in the dropdown property window public class ListItem { private string _Name; public string Name { get { return _Name; } set { _Name = value; } } private string _Value; public string Value { get { return _Value; } set { _Value = value; } }

问题 I am new to WPF. I just don't understand why there is a need for TypeConverters and IValueConverter in WPF. The purpose of both objects is to convert a value to specific type; but why both? Thanks in advance. 回答1: IValueConverter is used only in data-binding scenarios. It allows you to format values before they are displayed in the UI or to parse values from UI controls so that they can be stored in the binding source. an example would be to convert an IsDirty flag to an "*" in the UI or a

问题 I am new to WPF. I just don't understand why there is a need for TypeConverters and IValueConverter in WPF. The purpose of both objects is to convert a value to specific type; but why both? Thanks in advance. 回答1: IValueConverter is used only in data-binding scenarios. It allows you to format values before they are displayed in the UI or to parse values from UI controls so that they can be stored in the binding source. an example would be to convert an IsDirty flag to an "*" in the UI or a

问题 I'm trying to add a nested property to my custom control using a TypeConverter, here is my test code: public class TestNestedOptionConverter : TypeConverter { public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext context, object value, Attribute[] filter) { return TypeDescriptor.GetProperties(typeof(TestNestedOption)); } public override bool GetPropertiesSupported(ITypeDescriptorContext context) { return true; } } [TypeConverter(typeof(TestNestedOptionConverter))]

问题 Lets say we store KeyCode value as a string. How do you convert it back to KeyCode? For example, I've captured a key on keydown event: string modifier = e.Modifiers.ToString(); // Control string key_string = e.KeyCode.ToString(); // D1 How to do the following ? Keys old_key_restored = (Keys)key_string; Code above doesn't work. EDIT: Daniel is a life savior ;) Keys key_restored = (Keys) Enum.Parse(typeof(Keys), key_key); 回答1: Its just an enum so you can use Enum.TryParse 来源： https:/

问题 Lets say we store KeyCode value as a string. How do you convert it back to KeyCode? For example, I've captured a key on keydown event: string modifier = e.Modifiers.ToString(); // Control string key_string = e.KeyCode.ToString(); // D1 How to do the following ? Keys old_key_restored = (Keys)key_string; Code above doesn't work. EDIT: Daniel is a life savior ;) Keys key_restored = (Keys) Enum.Parse(typeof(Keys), key_key); 回答1: Its just an enum so you can use Enum.TryParse 来源： https:/

问题 currently i am working with ASP.NET and C# to store image into MySQL (using blob datatype). I'm storing it successfully into database, but now problem is, How can I retrieve that byte[] to image format ? FUNCTION: code to convert byte[] to image public Image byteArrayToImage(byte[] byteArrayIn) { MemoryStream ms = new MemoryStream(byteArrayIn); Image returnImage = Image.FromStream(ms); --> here gives me error as `parameter is not valid` return returnImage; } retieved as datatable... if (dt1

问题 currently i am working with ASP.NET and C# to store image into MySQL (using blob datatype). I'm storing it successfully into database, but now problem is, How can I retrieve that byte[] to image format ? FUNCTION: code to convert byte[] to image public Image byteArrayToImage(byte[] byteArrayIn) { MemoryStream ms = new MemoryStream(byteArrayIn); Image returnImage = Image.FromStream(ms); --> here gives me error as `parameter is not valid` return returnImage; } retieved as datatable... if (dt1

问题 I'd like to create a TypeConverter for a generic class, like this: [TypeConverter(typeof(WrapperConverter<T>))] public class Wrapper<T> { public T Value { // get & set } // other methods } public class WrapperConverter<T> : TypeConverter<T> { // only support To and From strings public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType) { if (sourceType == typeof(string)) { return true; } return base.CanConvertFrom(context, sourceType); } public override bool

问题 In php how do I convert a string "1010101010" into the integer value represented by this binary number? eg "10" would go to 2, "101" would go to 5 回答1: Use bindec() function to convert from binary to decimal: $value = bindec("10101011010101"); 回答2: Try the bindec() function. 来源： https://stackoverflow.com/questions/4424746/convert-binary-string-to-integer-in-php