ChoiceFormat Class
Definition
Important
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A ChoiceFormat allows you to attach a format to a range of numbers.
[Android.Runtime.Register("java/text/ChoiceFormat", DoNotGenerateAcw=true)]
public class ChoiceFormat : Java.Text.NumberFormat[<Android.Runtime.Register("java/text/ChoiceFormat", DoNotGenerateAcw=true)>]
type ChoiceFormat = class
inherit NumberFormat- Inheritance
- Attributes
Remarks
A ChoiceFormat allows you to attach a format to a range of numbers. It is generally used in a MessageFormat for handling plurals. The choice is specified with an ascending list of doubles, where each item specifies a half-open interval up to the next item: <blockquote>
X matches j if and only if limit[j] ≤ X < limit[j+1]
</blockquote> If there is no match, then either the first or last index is used, depending on whether the number (X) is too low or too high. If the limit array is not in ascending order, the results of formatting will be incorrect. ChoiceFormat also accepts \u221E as equivalent to infinity(INF).
<strong>Note:</strong> ChoiceFormat differs from the other Format classes in that you create a ChoiceFormat object with a constructor (not with a getInstance style factory method). The factory methods aren't necessary because ChoiceFormat doesn't require any complex setup for a given locale. In fact, ChoiceFormat doesn't implement any locale specific behavior.
When creating a ChoiceFormat, you must specify an array of formats and an array of limits. The length of these arrays must be the same. For example, <ul> <li> <em>limits</em> = {1,2,3,4,5,6,7}<br> <em>formats</em> = {"Sun","Mon","Tue","Wed","Thur","Fri","Sat"}<li> <em>limits</em> = {0, 1, ChoiceFormat.nextDouble(1)}<br> <em>formats</em> = {"no files", "one file", "many files"}<br> (nextDouble can be used to get the next higher double, to make the half-open interval.) </ul>
Here is a simple example that shows formatting and parsing: <blockquote>
{@code
double[] limits = {1,2,3,4,5,6,7};
String[] dayOfWeekNames = {"Sun","Mon","Tue","Wed","Thur","Fri","Sat"};
ChoiceFormat form = new ChoiceFormat(limits, dayOfWeekNames);
ParsePosition status = new ParsePosition(0);
for (double i = 0.0; i <= 8.0; ++i) {
status.setIndex(0);
System.out.println(i + " -> " + form.format(i) + " -> "
+ form.parse(form.format(i),status));
}
}
</blockquote> Here is a more complex example, with a pattern format: <blockquote>
{@code
double[] filelimits = {0,1,2};
String[] filepart = {"are no files","is one file","are {2} files"};
ChoiceFormat fileform = new ChoiceFormat(filelimits, filepart);
Format[] testFormats = {fileform, null, NumberFormat.getInstance()};
MessageFormat pattform = new MessageFormat("There {0} on {1}");
pattform.setFormats(testFormats);
Object[] testArgs = {null, "ADisk", null};
for (int i = 0; i < 4; ++i) {
testArgs[0] = new Integer(i);
testArgs[2] = testArgs[0];
System.out.println(pattform.format(testArgs));
}
}
</blockquote>
Specifying a pattern for ChoiceFormat objects is fairly straightforward. For example: <blockquote>
{@code
ChoiceFormat fmt = new ChoiceFormat(
"-1#is negative| 0#is zero or fraction | 1#is one |1.0<is 1+ |2#is two |2<is more than 2.");
System.out.println("Formatter Pattern : " + fmt.toPattern());
System.out.println("Format with -INF : " + fmt.format(Double.NEGATIVE_INFINITY));
System.out.println("Format with -1.0 : " + fmt.format(-1.0));
System.out.println("Format with 0 : " + fmt.format(0));
System.out.println("Format with 0.9 : " + fmt.format(0.9));
System.out.println("Format with 1.0 : " + fmt.format(1));
System.out.println("Format with 1.5 : " + fmt.format(1.5));
System.out.println("Format with 2 : " + fmt.format(2));
System.out.println("Format with 2.1 : " + fmt.format(2.1));
System.out.println("Format with NaN : " + fmt.format(Double.NaN));
System.out.println("Format with +INF : " + fmt.format(Double.POSITIVE_INFINITY));
}
</blockquote> And the output result would be like the following: <blockquote>
{@code
Format with -INF : is negative
Format with -1.0 : is negative
Format with 0 : is zero or fraction
Format with 0.9 : is zero or fraction
Format with 1.0 : is one
Format with 1.5 : is 1+
Format with 2 : is two
Format with 2.1 : is more than 2.
Format with NaN : is negative
Format with +INF : is more than 2.
}
</blockquote>
<h2>"synchronization">Synchronization</h2>
Choice formats are not synchronized. It is recommended to create separate format instances for each thread. If multiple threads access a format concurrently, it must be synchronized externally.
Added in 1.1.
Java documentation for java.text.ChoiceFormat.
Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.
Constructors
| ChoiceFormat(Double[], String[]) |
Constructs with the limits and the corresponding formats. |
| ChoiceFormat(IntPtr, JniHandleOwnership) |
A constructor used when creating managed representations of JNI objects; called by the runtime. |
| ChoiceFormat(String) |
Constructs with limits and corresponding formats based on the pattern. |
Fields
| FractionField |
Field constant used to construct a FieldPosition object. (Inherited from NumberFormat) |
| IntegerField |
Field constant used to construct a FieldPosition object. (Inherited from NumberFormat) |
Properties
| Class |
Returns the runtime class of this |
| Currency |
Gets the currency used by this number format when formatting currency values. -or- Sets the currency used by this number format when formatting currency values. (Inherited from NumberFormat) |
| GroupingUsed |
Returns true if grouping is used in this format. -or- Set whether or not grouping will be used in this format. (Inherited from NumberFormat) |
| Handle |
The handle to the underlying Android instance. (Inherited from Object) |
| JniIdentityHashCode | (Inherited from Object) |
| JniPeerMembers | |
| MaximumFractionDigits |
Returns the maximum number of digits allowed in the fraction portion of a number. -or- Sets the maximum number of digits allowed in the fraction portion of a number. (Inherited from NumberFormat) |
| MaximumIntegerDigits |
Returns the maximum number of digits allowed in the integer portion of a number. -or- Sets the maximum number of digits allowed in the integer portion of a number. (Inherited from NumberFormat) |
| MinimumFractionDigits |
Returns the minimum number of digits allowed in the fraction portion of a number. -or- Sets the minimum number of digits allowed in the fraction portion of a number. (Inherited from NumberFormat) |
| MinimumIntegerDigits |
Returns the minimum number of digits allowed in the integer portion of a number. -or- Sets the minimum number of digits allowed in the integer portion of a number. (Inherited from NumberFormat) |
| ParseIntegerOnly |
Returns true if this format will parse numbers as integers only. -or- Sets whether or not numbers should be parsed as integers only. (Inherited from NumberFormat) |
| PeerReference | (Inherited from Object) |
| RoundingMode |
Gets the |
| ThresholdClass |
This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. |
| ThresholdType |
This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. |
Methods
| ApplyPattern(String) |
Sets the pattern. |
| Clone() |
Creates and returns a copy of this object. (Inherited from _Format) |
| Dispose() | (Inherited from Object) |
| Dispose(Boolean) | (Inherited from Object) |
| Equals(Object) |
Indicates whether some other object is "equal to" this one. (Inherited from Object) |
| Format(Double) |
Specialization of format. (Inherited from NumberFormat) |
| Format(Double, StringBuffer, FieldPosition) |
Returns pattern with formatted double. |
| Format(Int64) |
Specialization of format. (Inherited from NumberFormat) |
| Format(Int64, StringBuffer, FieldPosition) |
Specialization of format. |
| Format(Object) |
Formats an object to produce a string. (Inherited from _Format) |
| Format(Object, StringBuffer, FieldPosition) |
Formats a number and appends the resulting text to the given string buffer. (Inherited from NumberFormat) |
| FormatToCharacterIterator(Object) |
Formats an Object producing an |
| GetFormats() |
Returns the strings associated with the ranges of this |
| GetHashCode() |
Returns a hash code value for the object. (Inherited from Object) |
| GetLimits() |
Returns the limits of this |
| JavaFinalize() |
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. (Inherited from Object) |
| NextDouble(Double) |
Finds the least double greater than |
| NextDouble(Double, Boolean) |
Finds the least double greater than |
| Notify() |
Wakes up a single thread that is waiting on this object's monitor. (Inherited from Object) |
| NotifyAll() |
Wakes up all threads that are waiting on this object's monitor. (Inherited from Object) |
| Parse(String) |
Parses text from the beginning of the given string to produce a number. (Inherited from NumberFormat) |
| Parse(String, ParsePosition) |
Parses a Number from the input text. |
| ParseObject(String) |
Parses text from the beginning of the given string to produce an object. (Inherited from _Format) |
| ParseObject(String, ParsePosition) |
Parses text from a string to produce a |
| PreviousDouble(Double) |
Finds the greatest double less than |
| SetChoices(Double[], String[]) |
Set the choices to be used in formatting. |
| SetHandle(IntPtr, JniHandleOwnership) |
Sets the Handle property. (Inherited from Object) |
| ToArray<T>() | (Inherited from Object) |
| ToPattern() |
Gets the pattern. |
| ToString() |
Returns a string representation of the object. (Inherited from Object) |
| UnregisterFromRuntime() | (Inherited from Object) |
| Wait() |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>. (Inherited from Object) |
| Wait(Int64) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
| Wait(Int64, Int32) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
Explicit Interface Implementations
| IJavaPeerable.Disposed() | (Inherited from Object) |
| IJavaPeerable.DisposeUnlessReferenced() | (Inherited from Object) |
| IJavaPeerable.Finalized() | (Inherited from Object) |
| IJavaPeerable.JniManagedPeerState | (Inherited from Object) |
| IJavaPeerable.SetJniIdentityHashCode(Int32) | (Inherited from Object) |
| IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates) | (Inherited from Object) |
| IJavaPeerable.SetPeerReference(JniObjectReference) | (Inherited from Object) |
Extension Methods
| JavaCast<TResult>(IJavaObject) |
Performs an Android runtime-checked type conversion. |
| JavaCast<TResult>(IJavaObject) | |
| GetJniTypeName(IJavaPeerable) | |