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范围问题-放下意图并从2个不同的功能开始活动

[英]Scope problem - put intent extra and start activity from 2 different functions

I have 2 listeners, 1 needs to get the intent extra, which is an image uri, and the other one needs to start the other activity with that extra. 我有2位听众,其中1位需要获得额外的意图,这是一个图像uri,另一位需要从该目标开始其他活动。 But I think that due to them being in different scopes, the extra is not really put for the intent that starts the other activity. 但是我认为,由于它们处于不同的范围,因此并未真正为启动其他活动的意图提供额外的费用。

This is the code: 这是代码:

        private Intent intent = new Intent(this, OtherActivity.class);
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            final Button button= findViewById(R.id.button);
            button.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    intent = new Intent(v.getContext(), OtherActivity.class);
                    startActivity(intent);
                }
            });


        }
        @Override
        protected void onActivityResult(int requestCode, int resultCode, Intent data) {

            if (requestCode == Thing.SPECIFIC_REQUEST_CODE) {
                Thing.ActivityResult result = Thing.getActivityResult(data);
                if (resultCode == RESULT_OK) {
                    Uri resultUri = result.getUri();
                    intent.putExtra("imageUri", resultUri.toString());    
                }
           }
   } 

I want that the extra that I put in onActivityResult will be sent to the activity started by the onClickListener when the button is clicked 我希望我在onActivityResult放入的额外内容将被发送到单击按钮时onClickListener启动的活动

my suggestion is to use a field to store the image URI : 我的建议是使用一个字段来存储图像URI:

1- define a String variable in your class 1-在您的类中定义一个String变量

String imageURI = "";

2- in your onActivityResult : 2-在您的onActivityResult中:

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        if (requestCode == Thing.SPECIFIC_REQUEST_CODE) {
            Thing.ActivityResult result = Thing.getActivityResult(data);
            if (resultCode == RESULT_OK) {
                Uri resultUri = result.getUri();
                imageURI = resultUri.toString();    
            }
       }

3-in your onClickListener : 3在您的onClickListener中:

        button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
            intent = new Intent(v.getContext(), OtherActivity.class);
                intent.putExtra("imageUri", imageURI);    
                startActivity(intent);
            }
        });

In the onClick you are re-initializing the Intent, so any extras you may have set are lost. onClick您正在重新初始化Intent,因此您可能设置的所有附加功能都将丢失。 If you remove the line above startActivity you should be fine. 如果删除startActivity上方的行,就可以了。

I would not go that way thought. 我不会那样想。 I would not have the Intent as a class variable but rather the image URI. 我不会将Intent作为类变量,而是将图像URI。 So whenever a click event happens, I would check for the image URI having been set, create a new Intent and then start the Activity. 因此,每当发生单击事件时,我都会检查是否已设置图像URI,创建新的Intent,然后启动Activity。

Your code would become like this: 您的代码将如下所示:

private String intentImage = null;

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

    final Button button = findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            if (intentImage != null) {
                Intent intent = new Intent(this, OtherActivity.class);
                intent.putExtra("imageUri", intentImage); 

                startActivity(intent);
            }
        });
    }
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == Thing.SPECIFIC_REQUEST_CODE) {
        Thing.ActivityResult result = Thing.getActivityResult(data);

        if (resultCode == RESULT_OK) {
            Uri resultUri = result.getUri();
            intentImage = resultUri.toString();    
        }
    }
}

Also keep in mind that you don't have any startActivityForResult in your code. 还请记住,您的代码中没有任何startActivityForResult So if this is your full activity, you would never get onActivityResult invoked. 因此,如果这是您的全部活动,则永远不会调用onActivityResult

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