【Android】Activity返回数据给上一个Activity

骑猪看日落 2022-11-17 03:38 233阅读 0赞

### Activity返回数据给上一个Activity ###

> **代码**

*  **kotlin:**

`FirstReturnActivity :`

class FirstReturnActivity : AppCompatActivity() {
        private lateinit var firstBinding: ActivityReturndataFirstBinding
        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            firstBinding = ActivityReturndataFirstBinding.inflate(layoutInflater)
            setContentView(firstBinding.root)
    
            firstBinding.firstGotoSecond.setOnClickListener {
                val intent = Intent(this, SecondReturnActivity::class.java)
                startActivityForResult(intent, 1)
            }
        }
    
        override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
            super.onActivityResult(requestCode, resultCode, data)
            when(requestCode){
                1->if (resultCode== RESULT_OK){
                    val returnedData=data?.getStringExtra("data_return")
                    Toast.makeText(this,returnedData,Toast.LENGTH_SHORT).show()
                }
            }
        }
    }

`SecondReturnActivity:`

class SecondReturnActivity: AppCompatActivity() {
        private lateinit var secondBinding: ActivityReturndataSecondBinding
        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            secondBinding= ActivityReturndataSecondBinding.inflate(layoutInflater)
            setContentView(secondBinding.root)
    
            secondBinding.secondReturn.setOnClickListener {
                val intent= Intent()
                intent.putExtra("data_return","Hello MainActivity")
                setResult(RESULT_OK,intent)
                finish()
            }
        }
    
        override fun onBackPressed() {
            val intent=Intent()
            intent.putExtra("data_return","Hello MainActivity")
            setResult(RESULT_OK,intent)
            finish()
        }
    }

*  **Layout:**

`两个布局各加一个按钮`

--------------------

> **效果:**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjQ3MzIyOA_size_16_color_FFFFFF_t_70]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjQ3MzIyOA_size_16_color_FFFFFF_t_70]: /images/20221022/09b7068e51344aa59cd67b6a860f1dca.png