Android开发中常见错误及其解决方法

1、Warning:Conflict with dependency 'com.google.code.findbugs:jsr305'. Resolved versions for app (3.0.1) and test app (2.0.1) differ. See http://g.co/androidstudio/app-test-app-conflict for details.

这个是库依赖的版本冲突问题，可以使用强制统一依赖版本，在build.gradle中添加如下代码：

android {
    compileSdkVersion 26
    buildToolsVersion "26.0.0"
    defaultConfig {
        applicationId "com.localgo.myapplication2"
        minSdkVersion 15
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
	
	//强制添加如下代码
	configurations.all {
		resolutionStrategy.force 'com.google.code.findbugs:jsr305:1.3.9'
	}
}

2、所有的后台Java文件的R变成红色，提示“cannot resolve symbol R”

依次点击 Build -> Rebuild Project and then click Tools -> Android -> Sync Project with Gradle Files.