Android中js和java互调传值
通过调用js计算两个数的和,js调用Android的hello方法
testjs.html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>JavaAndScript</title>
<script>
//js调用android的hello方法
function jscallandroid(){
test.hello("js调到了Android的hello方法");
}
//Android要调用的方法,计算a和b的和并且返回
function androidcalljs(a,b){
return a+b;
}
</script>
</head>
<body>
<button style="color: #FF0000;" onclick="jscallandroid()">网页里的按钮</button>
<p id="p1" ></p>
</body>
</html>
JavaAndJSActivity.java
package com.myapplication;
import android.app.Activity;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.webkit.JavascriptInterface;
import android.webkit.ValueCallback;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import butterknife.BindView;
import butterknife.OnClick;
public class JavaAndJSActivity extends Activity {
WebView webView;
Button btn;
EditText editText1,editText2;
TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_java_and_js);
webView = (WebView)findViewById(R.id.webview1);
btn = (Button)findViewById(R.id.btn1);
editText1 =(EditText)findViewById(R.id.et_1);
editText2 = (EditText)findViewById(R.id.et_2);
textView = (TextView)findViewById(R.id.tv1);
initwebview();
btnonclick();
}
private void initwebview(){
WebSettings webSettings = webView.getSettings();
//设置允许与js交互
webSettings.setJavaScriptEnabled(true);
// 先载入JS代码
// 格式规定为:file:///android_asset/文件名.html
webView.loadUrl("file:///android_asset/testjs.html");
// 通过addJavascriptInterface()将Java对象映射到JS对象
//参数1：Javascript对象名
//参数2：Java对象名
webView.addJavascriptInterface(new AndroidtoJs(),"test");
}
private void btnonclick(){
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//点击btn调用js里的androidcalljs（）方法,注意方法名要对上
webView.evaluateJavascript("javascript:androidcalljs("+editText1.getText().toString()+","+editText2.getText().toString()+")", new ValueCallback<String>() {
@Override
public void onReceiveValue(String value) {
//此处为 js 返回的结果
textView.setText(value);
}
});
}
});
}
public class AndroidtoJs{
@JavascriptInterface
public String hello(final String a ){
Toast.makeText(getApplication(),a,Toast.LENGTH_SHORT).show();
return textView.getText().toString();
}
}
}
运行效果
3.png
1.png
2.png
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