背景介绍

Android下面WebView开发，有时候需要调用底层的一部分接口，而这部分接口只有Android的SDK才提供相关的功能，这个时候就需要进行Java与JavaScript通信。

例子

生成JavaScript调用Java函数的接口类

Java

public class AndroidJavaScript { @JavascriptInterface public String getJavaString() { return new String("JavaString"); } }

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public class AndroidJavaScript {
@JavascriptInterface
public String getJavaString() {
return new String("JavaString");
}
}
开启 JavaScript支持，并向WebView注册接口

注册Javascript接口
Java

mWebView.getSettings().setJavaScriptEnabled(true); mWebView.addJavascriptInterface(new AndroidJavaScript(), "Android");

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mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.addJavascriptInterface(new AndroidJavaScript(), "Android");

Html中调用接口例子

<html>
    <head>
        <script type="text/javascript">
            var JavaString = window.Android.getJavaString()
            document.write(JavaString);
        </script>
    </head>
</html>

<html>

<head>

var JavaString = window.Android.getJavaString()

document.write(JavaString);

</script>

</head>

</html>

销毁的时候，反注册接口，避免内存泄漏

注册Javascript接口
Java

mWebView.removeJavascriptInterface("Android");

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mWebView.removeJavascriptInterface("Android");

销毁的时候，WebView从父容器中移除，避免内存泄漏

ViewParent viewParent = mWebView.getParent();
if(viewParent instanceof ViewGroup) {
    ViewGroup viewGroup = (ViewGroup)viewParent;
    viewGroup.removeView(mWebView);
}
mWebView.destroy();

ViewParent viewParent = mWebView.getParent();

if(viewParent instanceof ViewGroup) {

ViewGroup viewGroup = (ViewGroup)viewParent;

viewGroup.removeView(mWebView);

}

mWebView.destroy();

完整的例子代码如下（包含WebView的XML布局文件，请自行生成）：

import android.app.Activity;
import android.os.Bundle;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.webkit.JavascriptInterface;
import android.webkit.WebSettings;
import android.webkit.WebView;

public class MainActivity extends Activity {

    WebView mWebView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mWebView = (WebView)findViewById(R.id.jsBridgeWebView);
        WebSettings webSettings = mWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        mWebView.addJavascriptInterface(new AndroidJavaScript(), mJsInterfaceName);
        mWebView.loadDataWithBaseURL("blarg://ignored", mJsHtml, "text/html", "UTF-8", "");
    }

    @Override
    protected void onDestroy() {
        mWebView.removeJavascriptInterface(mJsInterfaceName);
        ViewParent viewParent = mWebView.getParent();
        if(viewParent instanceof ViewGroup) {
            ViewGroup viewGroup = (ViewGroup)viewParent;
            viewGroup.removeView(mWebView);
        }
        mWebView.destroy();
        super.onDestroy();
    }

    private static class AndroidJavaScript {
        @JavascriptInterface
        public String getString() {
            return new String("JavaString");
        }
    }

    private final String mJsInterfaceName = "Android";
    private final String mJsHtml = "<html>\n" +
            "\t<head>\n" +
            "\t\t<script type=\"text/javascript\">\n" +
            "\t\t\tvar str = window.Android.getString()\r\n" +
            "\t\t\tdocument.write(str)\n" +
            "\t\t</script>\n" +
            "\t</head>\n" +
            "</html>";
}

import android.app.Activity;

import android.os.Bundle;

import android.view.ViewGroup;

import android.view.ViewParent;

import android.webkit.JavascriptInterface;

import android.webkit.WebSettings;

import android.webkit.WebView;

public class MainActivity extends Activity {

WebView mWebView;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mWebView = (WebView)findViewById(R.id.jsBridgeWebView);

WebSettings webSettings = mWebView.getSettings();

webSettings.setJavaScriptEnabled(true);

mWebView.addJavascriptInterface(new AndroidJavaScript(), mJsInterfaceName);

mWebView.loadDataWithBaseURL("blarg://ignored", mJsHtml, "text/html", "UTF-8", "");

}

@Override

protected void onDestroy() {

mWebView.removeJavascriptInterface(mJsInterfaceName);

ViewParent viewParent = mWebView.getParent();

if(viewParent instanceof ViewGroup) {

ViewGroup viewGroup = (ViewGroup)viewParent;

viewGroup.removeView(mWebView);

}

mWebView.destroy();

super.onDestroy();

}

private static class AndroidJavaScript {

@JavascriptInterface

public String getString() {

return new String("JavaString");

}

private final String mJsInterfaceName = "Android";

private final String mJsHtml = "<html>\n" +

"\t<head>\n" +

"\t\t<script type=\"text/javascript\">\n" +

"\t\t\tvar str = window.Android.getString()\r\n" +

"\t\t\tdocument.write(str)\n" +

"\t\t</script>\n" +

"\t</head>\n" +

"</html>";

}

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Android下WebView中Java与JavaScript通信

背景介绍

例子

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背景介绍

例子

发布者

默默

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发表回复取消回复