java - 如何在另一个 Activity 中发生的成功事件中使按钮从不可见变为可见

Question

最初在我的 activity_main.xml 文件中有按钮 V1-V8 可见，R1-R8 不可见

我的 MainActivity.java 文件

package com.example.buttonvtor;

import com.example.buttonvtor.MainActivity;
import com.example.buttonvtor.Payment1Activity;
import com.example.buttonvtor.Payment2Activity;
import com.example.buttonvtor.Payment3Activity;
import com.example.buttonvtor.Payment4Activity;
import com.example.buttonvtor.Payment5Activity;
import com.example.buttonvtor.Payment6Activity;
import com.example.buttonvtor.Payment7Activity;
import com.example.buttonvtor.Payment8Activity;
import com.example.buttonvtor.R;
import android.os.Bundle;
import android.app.Activity;
import android.content.DialogInterface;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener{

Button bv1;
Button bv2;
Button bv3;
Button bv4;
Button bv5;
Button bv6;
Button bv7;
Button bv8;
Button br1;

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

    bv1 = (Button)findViewById(R.id.button1);
    bv2 = (Button)findViewById(R.id.button2);
    bv3 = (Button)findViewById(R.id.button3);
    bv4 = (Button)findViewById(R.id.button4);
    bv5 = (Button)findViewById(R.id.button5);
    bv6 = (Button)findViewById(R.id.button6);
    bv7 = (Button)findViewById(R.id.button7);
    bv8 = (Button)findViewById(R.id.button8);
            br1 = (Button)findViewById(R.id.r1);
    bv1.setOnClickListener(this);
    bv2.setOnClickListener(this);
    bv3.setOnClickListener(this);
    bv4.setOnClickListener(this);
    bv5.setOnClickListener(this);
    bv6.setOnClickListener(this);
    bv7.setOnClickListener(this);
    bv8.setOnClickListener(this);


}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}


public void onClick(View v) {
switch(v.getId()){

case R.id.button1:
Toast.makeText(MainActivity.this,"You clicked on block 1",Toast.LENGTH_LONG).show();
startActivityForResult(new Intent(MainActivity.this,Payment1Activity.class),1);
break;

case R.id.button2:
Toast.makeText(MainActivity.this,"You clicked on block 2",Toast.LENGTH_LONG).show();
startActivityForResult(new Intent(MainActivity.this,Payment2Activity.class),2);
break;

case R.id.button3:
Toast.makeText(MainActivity.this,"You clicked on block 3",Toast.LENGTH_LONG).show();
startActivityForResult(new Intent(MainActivity.this,Payment3Activity.class),3);
break;

case R.id.button4:
Toast.makeText(MainActivity.this,"You clicked on block 4",Toast.LENGTH_LONG).show();
startActivityForResult(new Intent(MainActivity.this,Payment4Activity.class),4);
break;

case R.id.button5:
Toast.makeText(MainActivity.this,"You clicked on block 5",Toast.LENGTH_LONG).show();
startActivityForResult(new Intent(MainActivity.this,Payment5Activity.class),5);
break;

case R.id.button6:
Toast.makeText(MainActivity.this,"You clicked on block 6",Toast.LENGTH_LONG).show();
startActivityForResult(new Intent(MainActivity.this,Payment6Activity.class),6);
break;

case R.id.button7:
Toast.makeText(MainActivity.this,"You clicked on block 7",Toast.LENGTH_LONG).show();
startActivityForResult(new Intent(MainActivity.this,Payment7Activity.class),7);
break;

case R.id.button8:
Toast.makeText(MainActivity.this,"You clicked on block 8",Toast.LENGTH_LONG).show();
startActivityForResult(new Intent(MainActivity.this,Payment8Activity.class),8);
break;
     }

    }

 protected void onActivityResult (int requestCode, int resultCode, Intent data)
  {
    if (requestCode == 1)
    {// here you match the number you sent in startActivityForResult
        if (resultCode == RESULT_OK)
       {
            bv1.setVisibility(View.INVISIBLE);
            br1.setVisibility(0);


        }
             // do something
    }
      }
  }

一旦我点击 say 按钮 V1，它就会转到下一个名为 Payment1Activity.java 的 Activity 并检查用户的有效性。如果用户有效且付款成功，它将返回到我的 MainActivity.java。

Payment1Activity.java

package com.example.buttonvtor;

import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.RemoteViews;


public class Payment1Activity extends Activity {
Button b;
EditText et,pass;
TextView tv;
HttpPost httppost;
StringBuffer buffer;
HttpResponse response;
HttpClient httpclient;
List<NameValuePair> nameValuePairs;
ProgressDialog dialog = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_payment1);
    b = (Button)findViewById(R.id.Button01);  
    et = (EditText)findViewById(R.id.accountno);
    pass= (EditText)findViewById(R.id.password);
    tv = (TextView)findViewById(R.id.tv);

    b.setOnClickListener(new OnClickListener() {


        @Override
        public void onClick(View v) {

            dialog = ProgressDialog.show(Payment1Activity.this, "", 
                    "Validating user...", true);
             new Thread(new Runnable() {
                    public void run() {
                        payment();                        
                    }
                  }).start();               
        }
    });
}

void payment(){
try{            

httpclient=new DefaultHttpClient();
httppost= new HttpPost("my url"); 
        //add your data
nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("accno",et.getText().toString().trim())); 
nameValuePairs.add(newBasicNameValuePair("bpassword",pass.getText().toString().trim()));                                   
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
        //Execute HTTP Post Request
response=httpclient.execute(httppost);
ResponseHandler<String> responseHandler = new BasicResponseHandler();
final String response = httpclient.execute(httppost, responseHandler);
System.out.println("Response : " + response); 
runOnUiThread(new Runnable() {
            public void run() {
                tv.setText("Response from PHP : " + response);
                dialog.dismiss();
            }
        });

    if(response.startsWith("User Found")){
runOnUiThread(new Runnable() {
   public void run() {
 Toast.makeText(Payment1Activity.this,"Payment Successful", Toast.LENGTH_SHORT).show();
 Toast.makeText(Payment1Activity.this,"You reserved block 1",Toast.LENGTH_LONG).show(); 
                }
    });
    Intent returnIntent = new Intent();
returnIntent.putExtra("Payment Successful",RESULT_OK);
setResult(RESULT_OK,returnIntent);     
finish();

   startActivity(new Intent(Payment1Activity.this, MainActivity.class));
}else{
            showAlert();                
        }

    }catch(Exception e){
        dialog.dismiss();
        System.out.println("Exception : " + e.getMessage());
    }
}
public void showAlert(){
Payment1Activity.this.runOnUiThread(new Runnable() {
      public void run() {
    AlertDialog.Builder builder = new AlertDialog.Builder(Payment1Activity.this);
builder.setTitle("Payment Error.");
builder.setMessage("User not Found.")  
          .setCancelable(false)
          .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                       public void onClick(DialogInterface dialog, int id) {
                       }
                   });                     
            AlertDialog alert = builder.create();
            alert.show();               
        }
    });
}
  }

所以我想要这样的东西，当我的 Payment1Activity.java 说支付成功并将用户重定向到主页时，我的 V1 按钮应该变得不可见，而 R1 应该变得可见。我尝试了不同的排列和组合来实现这一点，但没有帮助。请帮忙。任何建议或意见将不胜感激。谢谢。

Answer 1

在您的主 Activity 中使用 startActivityForResult 而不是 startActivity。这允许您将值从新 Activity 返回到主 Activity 。例如:

在主 Activity 中

startActivityForResult(new Intent(MainActivity.this,Payment3Activity.class), 3);

此处，数字 3 是您定义的数字，可让您稍后识别结果。在您的 Payment#Activity 中，您会在某个时候(例如，当您关闭您的 Activity 时)

setResult(RESULT_OK); // or any result you want

结果被发送到 MainActivity，您必须覆盖 onActivityResult() 才能获得结果。

protected void onActivityResult (int requestCode, int resultCode, Intent data)
{
    if (requestCode == 3) // here you match the number you sent in startActivityForResult
        if (resultcode == RESULT_OK)
             // do something
}