Unity Android findViewById与webview插件制作

最新推荐文章于 2025-06-27 10:12:18 发布

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本文介绍了解决Unity3D项目中WebView组件在Android平台上遇到的问题：一是通过findViewById获取对象为空导致的错误，二是WebView内嵌H5页面中默认不支持图片上传的功能扩展。

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最近在给Unity3D接入各个Android运营平台的插件，其中有一个webview 功能用于显示玩家客服系统，上面还要上传图片
发现2个问题

1、按照正常的工程来做，发现findViewById返回了一个null 导致了空指针异常。无论是直接用Unity编译apk还是用Unity导出Android工程，都会出现该问题。经过各种查找，最终找到了问题的原因。

问题的原因主要在于，在我们将自己的android工程打成jar插件时，原来的R.id.xxxxx已经被转换成相应的数字id编译进了jar包，而Unity3D在导出工程或是apk的时候，会对所有资源进行重新的id编译，这就导致我们jar中的旧id是无法获取到相应对象。解决办法如下：

//this.wv=(WebView)findViewById(R.id.ifree_brow_webview);  
int webviewID = getResources().getIdentifier("ifree_brow_webview", "id", getPackageName());  
this.wv = (WebView)findViewById(webviewID);

之后将Eclipse工程中src目录导出成jar包，千万不要导出R类

导出方法工程右键->Export->Java->JAR file 只选择src文件夹

2、webview内嵌h5页面中，默认安卓webview不支持上传图片要扩展下webview

代码要Android5.0以上

package com.pwrd.onesdk.demo;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.ClipData;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.webkit.JsResult;
import android.webkit.ValueCallback;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;

@SuppressLint("SetJavaScriptEnabled")
public class WebViewActivity extends Activity {

    private WebView webView;
    private Button close;
    private ValueCallback<Uri> mUploadMessage;
    private ValueCallback<Uri[]> mUploadMessages;
    private static int FILECHOOSER_RESULTCODE = 1001;
    private RelativeLayout mLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        this.setTheme(android.R.style.Theme_NoTitleBar_Fullscreen);

        mLayout = new RelativeLayout(this);

        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                ViewGroup.LayoutParams.MATCH_PARENT);
        webView = new WebView(getApplicationContext());
        webView.setLayoutParams(params);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.getSettings().setAppCacheEnabled(true);
        webView.getSettings().setCacheMode(WebSettings.LOAD_DEFAULT);
        webView.getSettings().setDomStorageEnabled(true);
        webView.getSettings().setAllowFileAccess(true);
        webView.getSettings().setAllowFileAccess(true);

        webView.getSettings().setDatabaseEnabled(true);

        Intent intent = getIntent();
        String url = intent.getStringExtra("urlstr");
        webView.loadUrl(url);

        webView.setWebViewClient(new WebViewClient() {  
            @Override  
            public boolean shouldOverrideUrlLoading(WebView view, String url) {   
                view.loadUrl(url);  
                return true;  
            }  
        });

        webView.setWebChromeClient(new WebChromeClient() {
            @Override
            public boolean onJsAlert(WebView view, String url, String message, JsResult result) {
                return super.onJsAlert(view, url, message, result);
            }

            @Override
            public boolean onJsConfirm(WebView view, String url, String message, JsResult result) {
                return super.onJsConfirm(view, url, message, result);
            }

            // For Android 5.0+ 重点重点
            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType) {
                if (mUploadMessage != null)
                    return;
                mUploadMessage = uploadMsg;
                Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                i.addCategory(Intent.CATEGORY_OPENABLE);
                i.setType("*/*");
                startActivityForResult(Intent.createChooser(i, "File Chooser"), WebViewActivity.FILECHOOSER_RESULTCODE);
            }

            // For Android < 3.0
            public void openFileChooser(ValueCallback<Uri> uploadMsg) {
                openFileChooser(uploadMsg, "");
            }

            // For Android > 4.1.1
            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
                openFileChooser(uploadMsg, acceptType);
            }

            @Override
            public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback,
                    FileChooserParams fileChooserParams) {
                if (mUploadMessages != null)
                    return false;
                mUploadMessages = filePathCallback;
                Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                i.addCategory(Intent.CATEGORY_OPENABLE);
                i.setType("*/*");
                startActivityForResult(Intent.createChooser(i, "文件选择"), WebViewActivity.FILECHOOSER_RESULTCODE);
                return true;
            }
        });

        mLayout.addView(webView);

        Button btn = new Button(this);
        btn.setText("close");
        RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        layoutParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
        btn.setLayoutParams(layoutParams);
        btn.setGravity(Gravity.BOTTOM);
        btn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                WebViewActivity.this.finish();

            }
        });
        mLayout.addView(btn);

        setContentView(mLayout);

        super.onCreate(savedInstanceState);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
        if (requestCode == FILECHOOSER_RESULTCODE) {
            if (null != mUploadMessage) {
                Uri result = intent == null || resultCode != RESULT_OK ? null : intent.getData();
                mUploadMessage.onReceiveValue(result);
                mUploadMessage = null;
            }
            if (null != mUploadMessages) {
                Uri result = intent == null || resultCode != RESULT_OK ? null : intent.getData();
                onActivityResultAboveL(requestCode, resultCode, intent);
            }
        }
    }

    @SuppressLint("NewApi")
    private void onActivityResultAboveL(int requestCode, int resultCode, Intent intent) {
        if (requestCode != FILECHOOSER_RESULTCODE || mUploadMessages == null)
            return;
        Uri[] results = null;
        if (resultCode == Activity.RESULT_OK) {
            if (intent != null) {
                String dataString = intent.getDataString();
                ClipData clipData = intent.getClipData();
                if (clipData != null) {
                    results = new Uri[clipData.getItemCount()];
                    for (int i = 0; i < clipData.getItemCount(); i++) {
                        ClipData.Item item = clipData.getItemAt(i);
                        results[i] = item.getUri();
                    }
                }
                if (dataString != null)
                    results = new Uri[] { Uri.parse(dataString) };
            }
        }
        mUploadMessages.onReceiveValue(results);
        mUploadMessages = null;
    }
}