java - 如何从对话框片段中打开新活动

Question

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

我无法找到在按钮的 onClick 中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();
    }
}

Answer 1

DialogFragmenthasgetActivity()和getContext()methods （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。

Answer 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);
                }
            });