React Native入坑记录

1.render中如果使用props，直接用this.props.xxx，如果是在JSX中，用{this.props.xxx}

 

 

 

2.警告each child in an array or iterator should have a unique "key" prop.

 

在<PickerItem ... /> 加一个 key="";

 

 

 

3.组件id：增加ref="xxx".使用时this.refs.xxx.state.yyyy

 

 

 

4.android发布后白屏

 

重新生成asset

 

 

 

5.生成asset时报错：A problem occurred starting process 'command 'node''

 

先执行./gradlew --stop

 

 

6.判断系统

 

import {

Platform,

} from 'react-native';

 

console.warn(Platform.OS);

 

 

7.Android发布后闪退深坑

首先手动在android目录下创建react.grandle,内容为：

def config = project.hasProperty("react") ? project.react : [];

def bundleAssetName = config.bundleAssetName ?: "index.android.bundle"
def entryFile = config.entryFile ?: "index.android.js"

// because elvis operator
def elvisFile(thing) {
    return thing ? file(thing) : null;
}

def reactRoot = elvisFile(config.root) ?: file("../../")
def jsBundleDirDebug = elvisFile(config.jsBundleDirDebug) ?:
        file("$buildDir/intermediates/assets/debug")
def jsBundleDirRelease = elvisFile(config.jsBundleDirRelease) ?:
        file("$buildDir/intermediates/assets/release")
def resourcesDirDebug = elvisFile(config.resourcesDirDebug) ?:
        file("$buildDir/intermediates/res/merged/debug")
def resourcesDirRelease = elvisFile(config.resourcesDirRelease) ?:
        file("$buildDir/intermediates/res/merged/release")
def inputExcludes = config.inputExcludes ?: ["android/**", "ios/**"]

def jsBundleFileDebug = file("$jsBundleDirDebug/$bundleAssetName")
def jsBundleFileRelease = file("$jsBundleDirRelease/$bundleAssetName")

task bundleDebugJsAndAssets(type: Exec) {
    // create dirs if they are not there (e.g. the "clean" task just ran)
    doFirst {
        jsBundleDirDebug.mkdirs()
        resourcesDirDebug.mkdirs()
    }

    // set up inputs and outputs so gradle can cache the result
    inputs.files fileTree(dir: reactRoot, excludes: inputExcludes)
    outputs.dir jsBundleDirDebug
    outputs.dir resourcesDirDebug

    // set up the call to the react-native cli
    workingDir reactRoot
    commandLine "react-native", "bundle", "--platform", "android", "--dev", "true", "--entry-file",
            entryFile, "--bundle-output", jsBundleFileDebug, "--assets-dest", resourcesDirDebug

    enabled config.bundleInDebug ?: false
}

task bundleReleaseJsAndAssets(type: Exec) {
    // create dirs if they are not there (e.g. the "clean" task just ran)
    doFirst {
        jsBundleDirRelease.mkdirs()
        resourcesDirRelease.mkdirs()
    }

    // set up inputs and outputs so gradle can cache the result
    inputs.files fileTree(dir: reactRoot, excludes: inputExcludes)
    outputs.dir jsBundleDirRelease
    outputs.dir resourcesDirRelease

    // set up the call to the react-native cli
    workingDir reactRoot
    commandLine "react-native", "bundle", "--platform", "android", "--dev", "false", "--entry-file",
            entryFile, "--bundle-output", jsBundleFileRelease, "--assets-dest", resourcesDirRelease

    enabled config.bundleInRelease ?: true
}

gradle.projectsEvaluated {
    // hook bundleDebugJsAndAssets into the android build process
    bundleDebugJsAndAssets.dependsOn mergeDebugResources
    bundleDebugJsAndAssets.dependsOn mergeDebugAssets
    processDebugResources.dependsOn bundleDebugJsAndAssets

    // hook bundleReleaseJsAndAssets into the android build process
    bundleReleaseJsAndAssets.dependsOn mergeReleaseResources
    bundleReleaseJsAndAssets.dependsOn mergeReleaseAssets
    processReleaseResources.dependsOn bundleReleaseJsAndAssets
}

然后在根目录下执行：

react-native bundle --platform android --dev false --entry-file index.android.js --bundle-output ./android/app/build/intermediates/assets/release/index.android.bundle --assets-dest ./android/app/build/intermediates/res/merged/release