从 android 活动调用 javascript 函数
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/15673509/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
calling javascript function from an android activity
提问by user2206969
I wan to call a javascript function from an android activity but it doesn't seem to work. I have used the android webview function webview.loadUrl("javascript:function()"); This is my android code:
我想从 android 活动调用 javascript 函数，但它似乎不起作用。我已经使用了 android webview 函数 webview.loadUrl("javascript:function()"); 这是我的安卓代码：
package com.example.web;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.webkit.WebView;
public class MainActivity extends Activity {
WebView webview;
int i=30;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
webview = (WebView)findViewById(R.id.webView1);
webview.getSettings().setJavaScriptEnabled(true);
webview.loadUrl("file:///android_asset/index.html");
webview.loadUrl("javascript:change(i)");
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
This is my html code:
这是我的 html 代码：
<html>
<body>
<div id="texta">text</div>
<script>
function change(num){
document.getElementById("texta").innerHTML=num;
}
</script>
</body>
</html>
回答by Tushar
It's likely your page isn't fully loaded by the time you're trying to execute the javascript. Can you try:
当您尝试执行 javascript 时，您的页面可能尚未完全加载。你能试一下吗：
webView.setWebViewClient(new WebViewClient() {
public void onPageFinished(WebView view, String url) {
view.loadUrl("javascript:change(i)");
}
});
回答by Han Tran
Try:
尝试：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
webview = (WebView)findViewById(R.id.webView1);
webview.getSettings().setJavaScriptEnabled(true);
webview.loadUrl("file:///android_asset/index.html");
webview.loadUrl("javascript:change("+String.valueOf(i)+")");
}
回答by hRb
Try it:
试试看：
String URL = "file:///android_asset/filename.html";
webviewBrowser=(WebView)findViewById(R.id.webview);
webview.getSettings().setJavaScriptEnabled(true);
webview.setWebViewClient(new WebViewClient(webview.loadUrl(URL));
回答by Christoforos
Try to change this :
尝试改变这一点：
webview.loadUrl("javascript:change(i)");
to this
对此
webview.loadUrl("javascript:change(" + i +")");
the way you have write it the "i" is not the variable "i" from your java code but just a String named "i".
您编写它的方式“i”不是您的java代码中的变量“i”，而只是一个名为“i”的字符串。
回答by Naveed Ahmad
What is "i", If "i" is a number then Specify the Number, if "i" is a character then kindly enclose it in double Quotes, you are calling a method of some arguments, so kindly correct your mistake.
什么是“i”，如果“i”是数字，则指定数字，如果“i”是字符，请将其括在双引号中，您正在调用某些参数的方法，因此请纠正您的错误。
回答by Sanjay Kumar
try webview.loadUrl("javascript:change(\""+i"\")");
试试 webview.loadUrl("javascript:change(\""+i"\")");
回答by Dhina k
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Activity MyActivity = this;
text=(EditText)findViewById(R.id.textValue);
Show=(Button)findViewById(R.id.textButton);
webView= (WebView) findViewById(R.id.webView);
getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
Window.PROGRESS_VISIBILITY_ON);
webView.setWebChromeClient(new WebChromeClient() {
public void onProgressChanged(WebView view, int progress) {
MyActivity .setTitle("Loading...");
MyActivity .setProgress(progress * 100);
if (progress == 100)
MyActivity .setTitle("Android Dhina");
}
});
webView.setWebViewClient(new WebViewClient());
webView.addJavascriptInterface(new WebAppInterface(this), "Android");
webView.getSettings().setJavaScriptEnabled(true);
webView.loadUrl("file:///android_asset/web.html");
Show.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
webView.loadUrl("javascript:callFromAndroidActivity
(\""+text.getText().toString()+"\")"); }
});
