編輯

共用方式為


UIFontDescriptor Class

Definition

Describes properties of a font, use to create fonts with certain features. Provides ways of finding fonts matching a description as well.

[Foundation.Register("UIFontDescriptor", true)]
[ObjCRuntime.Introduced(ObjCRuntime.PlatformName.iOS, 7, 0, ObjCRuntime.PlatformArchitecture.All, null)]
public class UIFontDescriptor : Foundation.NSObject, Foundation.INSCopying, Foundation.INSSecureCoding, IDisposable
type UIFontDescriptor = class
    inherit NSObject
    interface INSCoding
    interface INativeObject
    interface IDisposable
    interface INSCopying
    interface INSSecureCoding
Inheritance
UIFontDescriptor
Attributes
Implements

Remarks

Developers create UIFontDescriptors with a set of parameters they are interested in (font faces, font families, font attributes, fallbacks). You can consider these descriptors queries, which you can later use to create a concrete UIFont wit by using the FromDescriptor(UIFontDescriptor, nfloat) method.

These objects are immutable, once created, they can not be changed. But given a UIFontDescriptor, you can create a more precise font descriptor instance with new information. You can create a new UIFontDescriptor with more detailed font attributes using the CreateWithAttributes(UIFontAttributes) method, extend one by explicitly setting a font face or font family using the CreateWithFace(String) and CreateWithFamily(String) methods, specify a desired font size or a transformation matrix with the CreateWithSize(nfloat) and CreateWithMatrix(CGAffineTransform) methods, or request that certain stylistic traits be present with CreateWithTraits(UIFontDescriptorSymbolicTraits).

This class exposes various static properties that return the UIFontDescriptor that matches the user's global preferences (font sizes) as well as the system font. These properties are: PreferredHeadline, PreferredBody, PreferredSubheadline, PreferredFootnote, PreferredCaption1 and PreferredCaption2.

You can use the GetMatchingFontDescriptors(UIFontDescriptorAttribute[]) method to get a set of UIFontDescriptors that match your font explicitly, or you can use CreateWithTraits(UIFontDescriptorSymbolicTraits) and FromDescriptor(UIFontDescriptor, nfloat) methods to match implicitly.

The following example shows how to create two fonts: one with the preferred font for body text, and then a bold version of the same font:


// Creates a UIFont for the body text
var bodyDescriptor = UIFontDescriptor.PreferredBody;
UIFont bodyFont = UIFont.FromDescriptor (bodyDescriptor, 0);

// Creates a bold version of it:
var boldDescriptor = bodyDescriptor.CreateWithTraits (UIFontDescriptorSymbolicTraits.Bold);
UIFont boldBodyFont = UIFont.FromDescriptor (boldDescriptor, 0);

The members of this class can be used from a background thread.

Constructors

UIFontDescriptor()

Default constructor, initializes a new instance of this class.

UIFontDescriptor(IntPtr)

A constructor used when creating managed representations of unmanaged objects; Called by the runtime.

UIFontDescriptor(NSCoder)

A constructor that initializes the object from the data stored in the unarchiver object.

UIFontDescriptor(NSDictionary)

Creates a UIFontDescriptor using a set of attributes contained in the dictionary.

UIFontDescriptor(NSObjectFlag)

Constructor to call on derived classes to skip initialization and merely allocate the object.

UIFontDescriptor(UIFontAttributes)

Creates a font descriptor using the specified font attributes.

Properties

CascadeList

Specifies the list of sub descriptors to be used before the system default fallbacks.

CharacterSet

Describes the character set supported by the specified font.

Class (Inherited from NSObject)
ClassHandle

The handle for this class.

DebugDescription

A developer-meaningful description of this object.

(Inherited from NSObject)
Description

Description of the object, the Objective-C version of ToString.

(Inherited from NSObject)
Face

The font face.

Family

The font family.

FeatureSettings

Typographic and layout feature settings.

FixedAdvance

Override for font's fixed advance for individual glyphs.

FontAttributes

The font attributes.

Handle

Handle (pointer) to the unmanaged object representation.

(Inherited from NSObject)
IsDirectBinding (Inherited from NSObject)
IsProxy (Inherited from NSObject)
Matrix

Transformation matrix for the descriptor.

Name

Name of the descriptor.

PointSize

Point size in the descriptor.

PostscriptName

The font's PostScript name.

PreferredBody

Gets the UIFontDescriptor describing the preferred font for body text.

PreferredCallout

Gets the UIFontDescriptor describing the preferred font for callouts.

PreferredCaption1

Gets the UIFontDescriptor describing the preferred font for captions.

PreferredCaption2

Gets the UIFontDescriptor describing the preferred font for 'caption 2'.

PreferredFootnote

Gets the UIFontDescriptor describing the preferred font for footnotes.

PreferredHeadline

Gets the UIFontDescriptor describing the preferred font for headlines.

PreferredSubheadline

Gets the UIFontDescriptor describing the preferred font for subheadings.

PreferredTitle1

Gets the UIFontDescriptor describing the preferred font for titles ('Title 1').

PreferredTitle2

Gets the UIFontDescriptor describing the preferred font for level 2 titles ('Title 2').

PreferredTitle3

Gets the UIFontDescriptor describing the preferred font for level 3 titles ('Title 3').

RetainCount

Returns the current Objective-C retain count for the object.

(Inherited from NSObject)
Self (Inherited from NSObject)
Size

Font size (if set).

Superclass (Inherited from NSObject)
SuperHandle

Handle used to represent the methods in the base class for this NSObject.

(Inherited from NSObject)
SymbolicTraits

Font's Symbolic traits

TextStyle

Name of the style to use for text.

Traits

Font's traits.

VisibleName

The visible name for this descriptor.

WeakFeatureSettings

Weakly typed version of the feature settings.

WeakFontAttributes

(Weak) font attributes.

Zone (Inherited from NSObject)

Methods

AddObserver(NSObject, NSString, NSKeyValueObservingOptions, IntPtr)

Registers an object for being observed externally (using NSString keyPath).   Observed changes are dispatched to the observer’s object ObserveValue(NSString, NSObject, NSDictionary, IntPtr) method.

(Inherited from NSObject)
AddObserver(NSObject, String, NSKeyValueObservingOptions, IntPtr)

Registers an object for being observed externally (using string keyPath).   Observed changes are dispatched to the observer’s object ObserveValue(NSString, NSObject, NSDictionary, IntPtr) method.

(Inherited from NSObject)
AddObserver(NSString, NSKeyValueObservingOptions, Action<NSObservedChange>)

Registers an object for being observed externally using an arbitrary method.

(Inherited from NSObject)
AddObserver(String, NSKeyValueObservingOptions, Action<NSObservedChange>)

Registers an object for being observed externally using an arbitrary method.

(Inherited from NSObject)
AwakeFromNib()

Called after the object has been loaded from the nib file. Overriders must call base.AwakeFromNib().

(Inherited from NSObject)
BeginInvokeOnMainThread(Action) (Inherited from NSObject)
BeginInvokeOnMainThread(Selector, NSObject)

Invokes asynchrously the specified code on the main UI thread.

(Inherited from NSObject)
Bind(NSString, NSObject, String, NSDictionary) (Inherited from NSObject)
Bind(String, NSObject, String, NSDictionary)
Obsolete.
(Inherited from NSObject)
BindingInfo(String)
Obsolete.
(Inherited from NSObject)
BindingOptionDescriptions(String)
Obsolete.
(Inherited from NSObject)
BindingValueClass(String)
Obsolete.
(Inherited from NSObject)
CommitEditing() (Inherited from NSObject)
CommitEditing(NSObject, Selector, IntPtr) (Inherited from NSObject)
ConformsToProtocol(IntPtr)

Invoked to determine if this object implements the specified protocol.

(Inherited from NSObject)
Copy()

Performs a copy of the underlying Objective-C object.

(Inherited from NSObject)
Copy(NSZone)

Performs a copy of the underlying Objective-C object.

CreateWithAttributes(NSDictionary)

Creates a new UIFontDescriptor based on adding the provided attributes to the current descriptor.

CreateWithAttributes(UIFontAttributes)

Creates a new UIFontDescriptor based on adding the provided attributes to the current descriptor.

CreateWithFace(String)

Creates a new UIFontDescriptor based on setting a font face to the current descriptor.

CreateWithFamily(String)

Creates a new UIFontDescriptor based on setting a font family to the current descriptor.

CreateWithMatrix(CGAffineTransform)

Creates a new UIFontDescriptor based on setting a new transformation matrix to the current descriptor.

CreateWithSize(nfloat)

Creates a new UIFontDescriptor based on setting a new font size to the current descriptor.

CreateWithTraits(UIFontDescriptorSymbolicTraits)

Creates a new UIFontDescriptor based on setting a new symbolic traits to the current descriptor.

DangerousAutorelease() (Inherited from NSObject)
DangerousRelease() (Inherited from NSObject)
DangerousRetain() (Inherited from NSObject)
DidChange(NSKeyValueChange, NSIndexSet, NSString)

Indicates a change occurred to the indexes for a to-many relationship.

(Inherited from NSObject)
DidChange(NSString, NSKeyValueSetMutationKind, NSSet) (Inherited from NSObject)
DidChangeValue(String)

Indicates that a change occurred on the specified key.

(Inherited from NSObject)
Dispose()

Releases the resources used by the NSObject object.

(Inherited from NSObject)
Dispose(Boolean)

Releases the resources used by the NSObject object.

(Inherited from NSObject)
DoesNotRecognizeSelector(Selector)

Indicates that this object does not recognize the specified selector.

(Inherited from NSObject)
EncodeTo(NSCoder)

Encodes the state of the object on the provided encoder

Equals(NSObject) (Inherited from NSObject)
Equals(Object) (Inherited from NSObject)
ExposedBindings() (Inherited from NSObject)
FromAttributes(NSDictionary)

(Weak) Creates a UIFontDescriptor using a set of attributes contained in the dictionary.

FromAttributes(UIFontAttributes)

Creates a UIFontDescriptor using a set of attributes contained in the dictionary.

FromName(String, CGAffineTransform)

Creates a UIFontDescriptor using the specified name and transformation matrix.

FromName(String, nfloat)

Creates a UIFontDescriptor using the specified name and font size.

GetBindingInfo(NSString) (Inherited from NSObject)
GetBindingOptionDescriptions(NSString) (Inherited from NSObject)
GetBindingValueClass(NSString) (Inherited from NSObject)
GetDictionaryOfValuesFromKeys(NSString[])

Retrieves the values of the specified keys.

(Inherited from NSObject)
GetHashCode()

Generates a hash code for the current instance.

(Inherited from NSObject)
GetMatchingFontDescriptors(NSSet)

Retrieve a UIFontDescriptor with an explicit set of features.

GetMatchingFontDescriptors(UIFontDescriptorAttribute[])

Retrieve a UIFontDescriptor with an explicit set of features.

GetMethodForSelector(Selector) (Inherited from NSObject)
GetNativeField(String)
Obsolete.
(Inherited from NSObject)
GetNativeHash() (Inherited from NSObject)
GetObject(NSString)

Low-level/weak API to retrieve properties from the UIFontDescriptor.

GetPreferredDescriptorForTextStyle(NSString, UITraitCollection)

Returns the preferred font descriptor for the specified style and trait collection.

GetPreferredDescriptorForTextStyle(NSString)

Weakly-typed version of an API used to retrieve the user's desired font size.

GetPreferredDescriptorForTextStyle(UIFontTextStyle, UITraitCollection)

Returns the preferred font descriptor for the specified style and trait collection.

GetPreferredDescriptorForTextStyle(UIFontTextStyle)

Weakly-typed version of an API used to retrieve the user's desired font size.

Init() (Inherited from NSObject)
InitializeHandle(IntPtr, String) (Inherited from NSObject)
InitializeHandle(IntPtr) (Inherited from NSObject)
Invoke(Action, Double) (Inherited from NSObject)
Invoke(Action, TimeSpan) (Inherited from NSObject)
InvokeOnMainThread(Action) (Inherited from NSObject)
InvokeOnMainThread(Selector, NSObject)

Invokes synchrously the specified code on the main UI thread.

(Inherited from NSObject)
IsEqual(NSObject) (Inherited from NSObject)
IsKindOfClass(Class) (Inherited from NSObject)
IsMemberOfClass(Class) (Inherited from NSObject)
MarkDirty()

Promotes a regular peer object (IsDirectBinding is true) into a toggleref object.

(Inherited from NSObject)
MutableCopy()

Creates a mutable copy of the specified NSObject.

(Inherited from NSObject)
ObjectDidEndEditing(NSObject) (Inherited from NSObject)
ObserveValue(NSString, NSObject, NSDictionary, IntPtr)

Indicates that the value at the specified keyPath relative to this object has changed.

(Inherited from NSObject)
PerformSelector(Selector, NSObject, Double, NSString[]) (Inherited from NSObject)
PerformSelector(Selector, NSObject, Double)

Invokes the selector on the current instance and if the obj is not null, it passes this as its single parameter.

(Inherited from NSObject)
PerformSelector(Selector, NSObject, NSObject) (Inherited from NSObject)
PerformSelector(Selector, NSObject) (Inherited from NSObject)
PerformSelector(Selector, NSThread, NSObject, Boolean, NSString[]) (Inherited from NSObject)
PerformSelector(Selector, NSThread, NSObject, Boolean) (Inherited from NSObject)
PerformSelector(Selector) (Inherited from NSObject)
PrepareForInterfaceBuilder() (Inherited from NSObject)
RemoveObserver(NSObject, NSString, IntPtr)

Stops the specified observer from receiving further notifications of changed values for the specified keyPath and context.

(Inherited from NSObject)
RemoveObserver(NSObject, NSString)

Stops the specified observer from receiving further notifications of changed values for the specified keyPath.

(Inherited from NSObject)
RemoveObserver(NSObject, String, IntPtr)

Stops the specified observer from receiving further notifications of changed values for the specified keyPath and context.

(Inherited from NSObject)
RemoveObserver(NSObject, String)

Stops the specified observer from receiving further notifications of changed values for the specified keyPath.

(Inherited from NSObject)
RespondsToSelector(Selector)

Whether this object recognizes the specified selector.

(Inherited from NSObject)
SetNativeField(String, NSObject)
Obsolete.
(Inherited from NSObject)
SetNilValueForKey(NSString)

Sets the value of the specified key to null.

(Inherited from NSObject)
SetValueForKey(NSObject, NSString)

Sets the value of the property specified by the key to the specified value.

(Inherited from NSObject)
SetValueForKeyPath(IntPtr, NSString)

A constructor used when creating managed representations of unmanaged objects; Called by the runtime.

(Inherited from NSObject)
SetValueForKeyPath(NSObject, NSString)

Sets the value of a property that can be reached using a keypath.

(Inherited from NSObject)
SetValueForUndefinedKey(NSObject, NSString)

Indicates an attempt to write a value to an undefined key. If not overridden, raises an NSUndefinedKeyException.

(Inherited from NSObject)
SetValuesForKeysWithDictionary(NSDictionary)

Sets the values of this NSObject to those in the specified dictionary.

(Inherited from NSObject)
ToString()

Returns a string representation of the value of the current instance.

(Inherited from NSObject)
Unbind(NSString) (Inherited from NSObject)
Unbind(String)
Obsolete.
(Inherited from NSObject)
ValueForKey(NSString)

Returns the value of the property associated with the specified key.

(Inherited from NSObject)
ValueForKeyPath(NSString)

Returns the value of a property that can be reached using a keypath.

(Inherited from NSObject)
ValueForUndefinedKey(NSString)

Indicates an attempt to read a value of an undefined key. If not overridden, raises an NSUndefinedKeyException.

(Inherited from NSObject)
WillChange(NSKeyValueChange, NSIndexSet, NSString)

Indicates that the values of the specified indices in the specified key are about to change.

(Inherited from NSObject)
WillChange(NSString, NSKeyValueSetMutationKind, NSSet) (Inherited from NSObject)
WillChangeValue(String)

Indicates that the value of the specified key is about to change.

(Inherited from NSObject)

Extension Methods

GetDebugDescription(INSObjectProtocol)
GetAccessibilityCustomRotors(NSObject)

Gets the array of UIAccessibilityCustomRotor objects appropriate for this object.

SetAccessibilityCustomRotors(NSObject, UIAccessibilityCustomRotor[])

Sets the array of UIAccessibilityCustomRotor objects appropriate for this object.

Applies to

See also