记录react-native开发中的一些问题

1. android studio升级到3.0以上，执行./gradlew assembleRelease进行安卓打包apk时 报错：图片文件重复: Error: Duplicate resources
   解决方法： 在react-native中找到react.gradle文件，然后再文件中doFirst下边添加如下代码(参考issues)

            doLast {
                def moveFunc = { resSuffix ->
                    File originalDir = file("$buildDir/generated/res/react/release/drawable-${resSuffix}");
                    if (originalDir.exists()) {
                        File destDir = file("$buildDir/../src/main/res/drawable-${resSuffix}");
                        ant.move(file: originalDir, tofile: destDir);
                    }
                }
                moveFunc.curry("ldpi").call()
                moveFunc.curry("mdpi").call()
                moveFunc.curry("hdpi").call()
                moveFunc.curry("xhdpi").call()
                moveFunc.curry("xxhdpi").call()
                moveFunc.curry("xxxhdpi").call()
            }

2. 集成jpush-react-native时，安卓在debug环境下运行正常，但是打包apk时候发生如下错误 A5D2AEBB07892832D0AA8C21B7428155.jpg
   解决方法：参考githud上的issues 可以在android目录下的build.gradle中添加如下代码

subprojects {
    afterEvaluate {project ->
        if (project.hasProperty("android")) {
            android {
                compileSdkVersion 27     //do this in android/app/build.gradle too
                buildToolsVersion '27.0.3'  //do this in android/app/build.gradle too
            }
        }
    }
}

我的build.gradle文件内容：

buildscript {
    ext {
        buildToolsVersion = "27.0.3"
        minSdkVersion = 16
        compileSdkVersion = 27
        targetSdkVersion = 26
        supportLibVersion = "27.1.1"
    }
    repositories {
        google()
        jcenter()

    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.4'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        mavenLocal()
        jcenter()
        maven {
            // All of React Native (JS, Obj-C sources, Android binaries) is installed from npm
            url "$rootDir/../node_modules/react-native/android"
        }
    }
}


task wrapper(type: Wrapper) {
    gradleVersion = '4.4'
    distributionUrl = distributionUrl.replace("bin", "all")
}

subprojects {
    afterEvaluate {project ->
        if (project.hasProperty("android")) {
            android {
                compileSdkVersion 27     //do this in android/app/build.gradle too
                buildToolsVersion '27.0.3'  //do this in android/app/build.gradle too
            }
        }
    }
}

3. 安卓键盘弹出时会把绝对定位的组件和键盘一块弹上去
   解决方法：在AndroidManifest.xml 文件中的设置

<activity
  ...
  android:windowSoftInputMode="stateAlwaysHidden|adjustPan">
  ....
</activity>

4. 安卓禁止横屏
   在AndroidManifest.xml 文件中添加

<activity
  ...
  android:screenOrientation="portrait"
  ....
</activity>

5. 加载App中的图片资源
   方法一：使用uri 必须要指定大小

<Image source={{uri: 'app_icon'}} style={{width: 40, height: 40}} />

方法二：使用require('image!x')语法，无需指定尺寸

<Image source={require('image!app_icon')} style={styles.imageStyle} />