如何从对话框片段中打开新活动

Posted 2023-04-19

【中文标题】如何从对话框片段中打开新活动

【英文标题】：How to open a new activity from a dialog fragment

【发布时间】：2019-02-26 23:38:25

【问题描述】：

我的程序在 MainActivity.java 中运行时打开一个 DialogFragment 类

我希望能够单击该对话框的“中性按钮”并打开一个新活动 SensorDataDisplay.java

我在按钮的 onClick 中找不到引用上下文的正确方法。

package com.august.customtisensortagclient;

import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;

import java.util.ArrayList;

public class GetInfoDialog extends DialogFragment 


    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) 





        final String thisWhichGetInfoDialog = ((MainActivity)getActivity()).getWhichGetInfoDialog();
        final ArrayList<String> thisScannedDevicesArrayList =
                ((MainActivity)getActivity()).getScannedDevicesArrayList();
        final int thisIsInLeftConnectedDeviceDisplay = ((MainActivity)getActivity()).getIsInLeftConnectedDeviceDisplay();
        final int thisIsInRightConnectedDeviceDisplay = ((MainActivity)getActivity()).getIsInRightConnectedDeviceDisplay();
        int thisIsInThisConnectedDeviceDisplay = 0;

        if (thisWhichGetInfoDialog == "Left") 
            thisIsInThisConnectedDeviceDisplay = thisIsInLeftConnectedDeviceDisplay;
         else if (thisWhichGetInfoDialog == "Right")
            thisIsInThisConnectedDeviceDisplay = thisIsInRightConnectedDeviceDisplay;

        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        builder.setTitle(thisWhichGetInfoDialog + " Sensor Info");
        builder.setMessage("MAC Address: " + thisScannedDevicesArrayList.get(thisIsInThisConnectedDeviceDisplay));
        builder.setNeutralButton("View Data", new DialogInterface.OnClickListener() 
            @Override
            public void onClick(DialogInterface dialog, int which) 
                Intent myIntent = new Intent(?????, SensorDataDisplay.class);
                myIntent.putExtra("key", "TEST VALUE"); //Optional parameters
                ?????.startActivity(myIntent);
            
        );
        builder.setNegativeButton("Done", new DialogInterface.OnClickListener() 
            public void onClick(DialogInterface dialog, int id) 
                // User cancelled the dialog
            
        );
        return builder.create();
    

【参考方案1】：

DialogFragment 具有getActivity() 和getContext() 方法（它继承自Fragment），两者都适用于您的情况。如果您在从匿名类访问这些方法时遇到问题（不应该是这种情况），您可以使用 GetInfoDialog.this.getActivity() 语法。

【参考方案2】：

getActivity() 返回片段附加到的 Activity

builder.setNeutralButton("View Data", new DialogInterface.OnClickListener() 
                @Override
                public void onClick(DialogInterface dialog, int which) 
                    Intent myIntent = new Intent(getActivity(), SensorDataDisplay.class);
                    myIntent.putExtra("key", "TEST VALUE"); //Optional parameters
                    getActivity().startActivity(myIntent);
                
            );