Pass parameters safely and quickly between activities or fragments.
Read this in other languages: 中文, English, Change Log
- Add the JitPack repository to your build file
allprojects {
repositories {
...
maven { url 'https://jitpack.io' }
}
}
- Add the dependency
dependencies {
implementation 'com.github.ssseasonnn:Bracer:1.0.3'
}
Dear, it's all 2020. Are you still writing such code?
val param1 = intent.getStringExtra("param1")
//param1 may be null, so we have to determine null
if (param1 != null) {
//using param1
}
Or:
class ActivityB : AppCompatActivity() {
private fun gotoActivityA() {
val intent = Intent(this, ActivityA::class.java)
intent.putExtra("key_1", "123")
startActivity(intent)
}
}
class ActivityA : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
//oh shit, wtf!! 写错了key的名字,导致一直获取不到值
val valueA = intent.getStringExtra("key_l")
}
}
more than this:
//Oh my god! Does every Fragment need to be written like this?
class FragmentA : Fragment() {
var a: String = ""
var b: String = ""
companion object {
fun newFragment(a: String, b: String): FragmentA {
val fragmentA = FragmentA()
val bundle = Bundle()
bundle.putString("key_a", a)
bundle.putString("key_b", b)
fragmentA.arguments = bundle
return fragmentA
}
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
arguments?.let {
a = it.getString("key_a") ?: ""
b = it.getString("key_b") ?: ""
}
}
}
I just want to simply pass a parameter, why should I write so much code? ? ? I am so tired...
Don't be afraid, now you have ** Bracer !! **
Let's see how the new century should pass parameters correctly
Get parameters in Fragment:
class MutableParamsFragment : Fragment() {
//basic type
var intParams by mutableParams<Int>()
var booleanParams by mutableParams<Boolean>()
var stringParams by mutableParams<String>()
//Custom type
var customParams by mutableParams<CustomParams1>()
//list
var intListParams by mutableParams<ArrayList<Int>>()
var stringListParams by mutableParams<ArrayList<String>>()
//array
var intArrayParams by mutableParams<IntArray>()
var arrayCustomParams by mutableParams<Array<CustomParams1>>()
//Any other type
//...
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
//Use directly, no need to manually read from Arguments
println(intParams)
println(booleanParams)
println(stringParams)
println(customParams)
println(intListParams)
println(stringListParams)
println(intArrayParams)
}
}
As you can see, getting parameters from Fragment is so simple and very safe! !!
And supports almost all types!
You will no longer encounter null pointer null, all parameters will have default values; You won't encounter wrong key writing. All parameters use their own names as keys by default.
Equivalent to: val byteParams = arguments.getByte("byteParams", 0) var stringParams = arguments.getString("stringParams") ?: ""
Let's see how to pass parameters:
val fragment = MutableParamsFragment().apply {
intParams = 1 //Just assign
booleanParams = true
stringParams = "123"
customParams = CustomParams1()
intListParams = arrayListOf(1,2,3)
intArrayParams = IntArray(2) { it }
}
//show this Fragment
val beginTransaction = supportFragmentManager.beginTransaction()
beginTransaction.add(R.id.frameLayout, fragment, "")
beginTransaction.commit()
Amazing!! Yes, it is so magical, passing parameters is as simple as that!
Let ’s take a look at Activity
class MutableParamsActivity : AppCompatActivity() {
//basic type
var intParams by mutableParams<Int>()
var booleanParams by mutableParams<Boolean>()
var stringParams by mutableParams<String>()
//Custom type
var customParams by mutableParams<CustomParams1>()
//list
var intListParams by mutableParams<ArrayList<Int>>()
var stringListParams by mutableParams<ArrayList<String>>()
//array
var intArrayParams by mutableParams<IntArray>()
var arrayCustomParams by mutableParams<Array<CustomParams1>>()
//Any other type
//...
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_test)
//Use it directly, no need to manually read from Intent anymore
println(intParams)
println(booleanParams)
println(stringParams)
println(customParams)
println(intListParams)
println(stringListParams)
println(intArrayParams)
}
}
Similar to Fragment, getting parameters from Activity is still so simple and still very safe! !! You will no longer encounter null pointer null, all parameters will have default values; You won't encounter wrong key writing. All parameters use their own names as keys by default.
Equivalent to: val byteParams = intent.getByteExtra("byteParams", 0) var stringParams = intent.getStringExtra("stringParams") ?: ""
Let's see how to pass parameters:
MutableParamsActivity().apply {
intParams = 1 //Just assign
booleanParams = true
stringParams = "123"
customParams = CustomParams1()
intListParams = arrayListOf(1,2,3)
intArrayParams = IntArray(2) { it }
}.start(context)
? ? ? Are you sure you wrote correctly? Why can we create an Activity? ? ?
Yes, it ’s so amazing, it is almost the same as Fragment usage, just a little bit of a show!
In addition, Bracer also supports some other features.
For example a custom key:
var customKeyParams by mutableParams<Byte>("this is custom key")
Or support custom defaults:
var defaultParams by mutableParams<BigDecimal>(defaultValue = BigDecimal.ONE)
Copyright 2019 Season.Zlc Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.