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';android.text.Editable android.widget.EditText.getText()';关于空对象引用_Android_Nullpointerexception - Fatal编程技术网

';android.text.Editable android.widget.EditText.getText()';关于空对象引用

';android.text.Editable android.widget.EditText.getText()';关于空对象引用,android,nullpointerexception,Android,Nullpointerexception,每当我单击该按钮时,我都会得到“在空对象引用上尝试调用虚拟方法”android.text.Editable android.widget.EditText.getText()。请帮忙 protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); edt

每当我单击该按钮时,我都会得到“在空对象引用上尝试调用虚拟方法”android.text.Editable android.widget.EditText.getText()。请帮忙

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        edt = (EditText) findViewById(R.id.edit);
        b1 = (Button) findViewById(R.id.button);

        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(MainActivity.this, Main2Activity.class);
                startActivity(i);
            }
        })
    }

    String tt(){
        return (edt.getText()+"");
    }


public class Main2Activity extends AppCompatActivity {
    MainActivity ob = new MainActivity();
    private WebView mywebview;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        mywebview=(WebView)findViewById(R.id.abc);
        WebSettings webSettings=mywebview.getSettings();
        webSettings.setJavaScriptEnabled(true);
        mywebview.loadUrl(ob.tt());
        mywebview.setWebViewClient(new WebViewClient());
    }
}

MainActivity ob=新的MainActivity()
将获得该类的一个简单对象,而不是当前正在运行的实际对象,因此
ob
在这种情况下是无用的,请删除
ob
相关代码并使用
Intent
传递数据

在第一个
main活动中

 b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(MainActivity.this, Main2Activity.class);
                i.putExtra("data",edt.getText().toString());
                //              ^^^^ pass data
                startActivity(i);
            }
        })
main2活动中

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        mywebview=(WebView)findViewById(R.id.abc);
        WebSettings webSettings=mywebview.getSettings();
        webSettings.setJavaScriptEnabled(true);
        mywebview.loadUrl(getIntent().getStringExtra("data"));
                                    // ^^^^^
        mywebview.setWebViewClient(new WebViewClient());
    }
也读