我想开始一个新的活动在我的Andr​​oid应用程序，我想从第一个活动传递一个简单的字符串，以第二个活动。我想在一个TextView现在在第二个活动的字符串来显示，但它只是将无法正常工作。我究竟做错了什么？

I'm trying to start a new activity in my android app, and I'm trying to pass a simple string from the first activity to the second activity. I want the string to display in a textview for now in the second activity, but it just won't work. What am I doing wrong?

最初的活动：

package com.amritayalur.mypowerschool;



import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.text.method.ScrollingMovementMethod;
import android.view.Gravity;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;



public class MyPowerSchoolActivity extends Activity {
Button buttonSubmit;
TextView TextViewTitle;
TextView TextViewDesc;
EditText EditTextURL;
String url = "";
 String str;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);


    buttonSubmit = (Button) findViewById(R.id.buttonSubmit);
    TextViewTitle = (TextView) findViewById(R.id.TextViewTitle);
    TextViewDesc = (TextView) findViewById(R.id.TextViewDesc);

    EditTextURL = (EditText) findViewById(R.id.EditTextURL);


    //Start TextView
    TextViewTitle.setText("MyPowerSchool");


    //button listener
    buttonSubmit.setOnClickListener(new View.OnClickListener() {


        String url = EditTextURL.getText().toString();


        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Intent i = new Intent( MyPowerSchoolActivity.this,
creds.class);    


            i.putExtra("pschoolurl", url);
            final int result = 1;
            startActivityForResult(i, result); 

        }

    });



}       
}

第二项活动：

The second activity:

package com.amritayalur.mypowerschool;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Gravity;
import android.webkit.WebView;
import android.widget.Toast;
import android.widget.TextView;



public class creds extends Activity {

String test;
TextView TextViewTest;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.second);




    Intent intent = getIntent();
    String test = intent.getExtras().getString("pschoolurl");

    TextViewTest = (TextView) findViewById(R.id.TextViewTest);
    TextViewTest.setText(test);

}
}

我知道TextView的正确显示在第二活动;它的工作原理与任何虚拟文本，只是不变量。

I know the textview displays properly in the second activity; it works with any dummy text, just not the variable.

推荐答案

您实例化字符串为时尚早，创建侦听器时，相反，你应该得到它时，监听器被调用：

You instantiate the string way too early, when creating the listener, instead, you should get it when the listener gets called:

    @Override
    public void onClick(View v) {
        Intent i = new Intent( MyPowerSchoolActivity.this, creds.class);    
        i.putExtra("pschoolurl", EditTextURL.getText().toString());
        // get the text here     ^^^
        final int result = 1;
        startActivityForResult(i, result); 
    }

顺便说一句，请遵循命名约定，用小写字母开头的变量（editTextURL）就会使code减少混乱为其他人（比如我:)）

BTW, please follow the naming conventions and start variables with a lower-case letter (editTextURL) it will make the code less confusing for other people (like me :) )