Android：视图类和活动类的 startActivityForResult & setResult

Question

我很困惑，不知道如何使用 startActivityResults 和 setResults 从以前的活动中获取数据。我有一个视图类和一个活动类。

基本上，在我的视图类中，我有这个对话框，它实际上会启动名为 colorActivity 类的活动类。当用户选择是时，它也会将所选圆圈的名称传递给 colorActivity 类。在 colorActivity 类中，允许用户输入特定圆圈的颜色代码，我想将颜色代码传递回视图类。我在使用 startActivityForResult 和 setResult 方法将值从活动传递回视图时遇到问题。补充一下，获取到的数据之后如何使用？

我的代码如下

我的视图类中的 Ontouchevent 代码：

            @Override
            public boolean onTouchEvent(MotionEvent event) {

                x = event.getX();
                y = event.getY();


                switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:


                    for (int i = 0; i < circles.size(); i++) {


                        if (circles.get(i).contains(x, y)) {
                            circleID = i;

            Handler handler = new Handler();
                                handler.postDelayed(new Runnable() {
                                    @Override
                                    public void run() {
                                        AlertDialog.Builder builder = new Builder(
                                                getContext());
                                        final EditText text = new EditText(getContext());

                                        builder.setTitle("Adding colors to circles").setMessage(
                                                "Proceed to Enter color");
                                        builder.setPositiveButton("Yes",
                                                new DialogInterface.OnClickListener() {

                                                    public void onClick(DialogInterface di,
                                                            int i) {

                                                        Intent intent = new Intent(
                                                                getContext(),
                                                                colorActivity.class);

                                                         intent.putExtra("circlename", circleNameList.get(circleID));


    startActivityForResults(intent, 1); // error incurred here : The method startActivityForResult(Intent, int) is undefined for the type new DialogInterface.OnClickListener(){}
                                                    }

                                                });
                                        builder.setNegativeButton("No",
                                                new DialogInterface.OnClickListener() {

                                                    public void onClick(DialogInterface di,
                                                            int i) {
                                                    }

                                                });

                                        builder.create().show();
                                    }
                                }, 3000);
    break;

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == 1) { // Please, use a final int instead of hardcoded
                                // int value
            if (resultCode == RESULT_OK) {
                 ccode = (String) data.getExtras().getString("colorcode");
        }

        }
    }

public static String getColorCode() {
        return ccode;
    }

在colorActivity中：

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


        circlenametextview = (TextView)findViewById(R.id.circlenametextview);


        String circlename = super.getIntent().getStringExtra("circlename");
          circlenametextview.setText(circlename);//get the circle name


savebutton.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {

                 Intent intent = new Intent(colorActivity.this, ?????);//how to return back to the view class?


               colorcode = colorEditText.getText().toString();// I am able to get value right up till this point
              Intent resultIntent = new Intent();
                   resultIntent.putExtra("colorcode", colorcode );

                   setResult(Activity.RESULT_OK, resultIntent);
                   finish();
            }// onclick

        });
        }

Answer 1

在更正其他代码以便您可以运行程序之后，您可以通过这种方式从您的活动colorActivity 中检索参数：

Step1：从colorActivity返回一些值

Intent resultIntent = new Intent();
resultIntent.putExtra("NAME OF THE PARAMETER", valueOfParameter);
...
setResult(Activity.RESULT_OK, resultIntent);
finish();

第 2 步：从 Main Activity 收集数据

覆盖@onActivityResult(...)。

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1) { // Please, use a final int instead of hardcoded int value
    if (resultCode == RESULT_OK) {
        String value = (String) data.getExtras().getString("NAME OF THE PARAMETER");

参考文献

• http://developer.android.com/training/basics/intents/result.html
• How to manage `startActivityForResult` on Android?
• http://steveliles.github.io/returning_a_result_from_an_android_activity.html

Answer 2

STARTACTIVITYFORRESULT 现已弃用

替代它和推荐的解决方案是使用Activity Result API

您可以使用此代码，用 Kotlin 语言编写：

1. 创建 ResultLauncher：

    private var resultLauncher =
    registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
        if (result.resultCode == Activity.RESULT_OK) {
            val data: Intent? = result.data
            if (null != data && data.getBooleanExtra("REFRESH_PAGE", false)) {
                //do your code here
            }
        }
    }
   

2. 使用上述结果启动器启动 Activity：

        val intent = Intent(this, XYZActivity::class.java)
        resultLauncher.launch(intent)
   

3. XYZActivity by 的返回结果

        val resultIntent = Intent()
        resultIntent.putExtra("REFRESH_PAGE", true)
        setResult(Activity.RESULT_OK, resultIntent)
        finish()
   

Answer 3

尝试使用

ActivityName.this.startActivityForResult(intent,int)

哦，还有一件小事，在您使用的代码中

startActivityForResults(intent,int) ..替换为

startActivityForResult(intent,int)