UriMatcher 類別

定義

[Android.Runtime.Register("android/content/UriMatcher", DoNotGenerateAcw=true)]
public class UriMatcher : Java.Lang.Object

[<Android.Runtime.Register("android/content/UriMatcher", DoNotGenerateAcw=true)>]
type UriMatcher = class
    inherit Object

繼承

Object

JavaObject

Object

UriMatcher

屬性

RegisterAttribute

備註

工具類別協助內容提供者中匹配 URI。

要使用這個類別，先建立一個物件樹 UriMatcher 。 例如：

private static final int PEOPLE = 1;
                private static final int PEOPLE_ID = 2;
                private static final int PEOPLE_PHONES = 3;
                private static final int PEOPLE_PHONES_ID = 4;
                private static final int PEOPLE_CONTACTMETHODS = 7;
                private static final int PEOPLE_CONTACTMETHODS_ID = 8;

                private static final int DELETED_PEOPLE = 20;

                private static final int PHONES = 9;
                private static final int PHONES_ID = 10;
                private static final int PHONES_FILTER = 14;

                private static final int CONTACTMETHODS = 18;
                private static final int CONTACTMETHODS_ID = 19;

                private static final int CALLS = 11;
                private static final int CALLS_ID = 12;
                private static final int CALLS_FILTER = 15;

                private static final UriMatcher sURIMatcher = new UriMatcher(UriMatcher.NO_MATCH);

                static
                {
                    sURIMatcher.addURI("contacts", "people", PEOPLE);
                    sURIMatcher.addURI("contacts", "people/#", PEOPLE_ID);
                    sURIMatcher.addURI("contacts", "people/#/phones", PEOPLE_PHONES);
                    sURIMatcher.addURI("contacts", "people/#/phones/#", PEOPLE_PHONES_ID);
                    sURIMatcher.addURI("contacts", "people/#/contact_methods", PEOPLE_CONTACTMETHODS);
                    sURIMatcher.addURI("contacts", "people/#/contact_methods/#", PEOPLE_CONTACTMETHODS_ID);
                    sURIMatcher.addURI("contacts", "deleted_people", DELETED_PEOPLE);
                    sURIMatcher.addURI("contacts", "phones", PHONES);
                    sURIMatcher.addURI("contacts", "phones/filter/*", PHONES_FILTER);
                    sURIMatcher.addURI("contacts", "phones/#", PHONES_ID);
                    sURIMatcher.addURI("contacts", "contact_methods", CONTACTMETHODS);
                    sURIMatcher.addURI("contacts", "contact_methods/#", CONTACTMETHODS_ID);
                    sURIMatcher.addURI("call_log", "calls", CALLS);
                    sURIMatcher.addURI("call_log", "calls/filter/*", CALLS_FILTER);
                    sURIMatcher.addURI("call_log", "calls/#", CALLS_ID);
                }

從 API 層級 android.os.Build.VERSION_CODES#JELLY_BEAN_MR2開始，路徑可以以前導斜線開頭。 例如：

sURIMatcher.addURI("contacts", "/people", PEOPLE);

當你需要與 URI 比對時，呼叫 #match，並提供你所獲得的 URL。 你可以用這個結果來建立查詢、回傳型別、插入或刪除一列，或做任何你需要的操作，而不必重複所有原本需要的 if-else 邏輯。 例如：

public String getType(Uri url)
                {
                    int match = sURIMatcher.match(url);
                    switch (match)
                    {
                        case PEOPLE:
                            return "vnd.android.cursor.dir/person";
                        case PEOPLE_ID:
                            return "vnd.android.cursor.item/person";
            ... snip ...
                            return "vnd.android.cursor.dir/snail-mail";
                        case PEOPLE_ADDRESS_ID:
                            return "vnd.android.cursor.item/snail-mail";
                        default:
                            return null;
                    }
                }

而不是：

public String getType(Uri url)
                {
                    List<String> pathSegments = url.getPathSegments();
                    if (pathSegments.size() >= 2) {
                        if ("people".equals(pathSegments.get(1))) {
                            if (pathSegments.size() == 2) {
                                return "vnd.android.cursor.dir/person";
                            } else if (pathSegments.size() == 3) {
                                return "vnd.android.cursor.item/person";
            ... snip ...
                                return "vnd.android.cursor.dir/snail-mail";
                            } else if (pathSegments.size() == 3) {
                                return "vnd.android.cursor.item/snail-mail";
                            }
                        }
                    }
                    return null;
                }

Java 文件 android.content.UriMatcher。

本頁部分內容為基於 Open Source Project 所創建與分享的作品，並依授權條款所描述的使用進行修改。