程序化视图如何设置唯一 ID? [英] Programmatic Views how to set unique id's?

问题描述

我正在我的应用程序中创建一堆程序化的View.看起来它们在默认情况下都具有相同的 id=-1.为了与他们合作，我需要生成唯一的 ID.

I am creating in my app bunch of programmatic Views. As it appeared to be they all by default have the same id=-1. In order to work with them I need to generate unique id's.

我尝试了几种方法 - 随机数生成并基于当前时间，但无论如何不能 100% 保证不同的视图会有不同的 id

I have tried several approaches - random number generation and based on current time, but anyway there's no 100% guarantee that different Views will have different id's

只是想知道有没有更可靠的方法来生成独特的?可能有特殊的方法/类?

Just wondering is there any more reliable way to generate unique ones? Probably there's special method/class?

推荐答案

只是对@phantomlimb 的回答的补充，

Just an addition to the answer of @phantomlimb,

而 View.generateViewId() 需要 API 级别 >= 17，
此工具兼容所有 API.

while View.generateViewId() require API Level >= 17,
this tool is compatibe with all API.

根据当前的 API 级别，
它使用系统 API 来决定天气.

according to current API Level,
it decide weather using system API or not.

所以你可以使用 ViewIdGenerator.generateViewId() 和 View.generateViewId()同时，不用担心得到相同的id

so you can use ViewIdGenerator.generateViewId() and View.generateViewId() in the same time and don't worry about getting same id

import java.util.concurrent.atomic.AtomicInteger;

import android.annotation.SuppressLint;
import android.os.Build;
import android.view.View;

/**
 * {@link View#generateViewId()}要求API Level >= 17,而本工具类可兼容所有API Level
 * <p>
 * 自动判断当前API Level,并优先调用{@link View#generateViewId()},即使本工具类与{@link View#generateViewId()}
 * 混用,也能保证生成的Id唯一
 * <p>
 * =============
 * <p>
 * while {@link View#generateViewId()} require API Level >= 17, this tool is compatibe with all API.
 * <p>
 * according to current API Level, it decide weather using system API or not.<br>
 * so you can use {@link ViewIdGenerator#generateViewId()} and {@link View#generateViewId()} in the
 * same time and don't worry about getting same id
 * 
 * @author [e-mail]
 */
public class ViewIdGenerator {
    private static final AtomicInteger sNextGeneratedId = new AtomicInteger(1);

    @SuppressLint("NewApi")
    public static int generateViewId() {

        if (Build.VERSION.SDK_INT < 17) {
            for (;;) {
                final int result = sNextGeneratedId.get();
                // aapt-generated IDs have the high byte nonzero; clamp to the range under that.
                int newValue = result + 1;
                if (newValue > 0x00FFFFFF)
                    newValue = 1; // Roll over to 1, not 0.
                if (sNextGeneratedId.compareAndSet(result, newValue)) {
                    return result;
                }
            }
        } else {
            return View.generateViewId();
        }

    }
}

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