Question

我是Android开发的初学者。可以任意1请指导我如何调用其他包下的类的方法。

与包1中的类A类似，调用包2的类B中的方法，该方法返回一个数组或对象。

我必须为此创建一个Intent吗？实际上，我必须从不同包中的不同类中收集1个类中的所有信息。

提前致谢。

package com.xyz.Master;


import android.app.Activity;
import android.content.Context;
import android.os.Build;
import android.telephony.CellLocation;
import android.telephony.TelephonyManager;
import android.telephony.gsm.GsmCellLocation;

public class PhoneInfo extends Activity {

TelephonyManager tm = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
GsmCellLocation location = (GsmCellLocation) tm.getCellLocation();  
public int cellID, lac,mcc,mnc;
public String imei,manufacturer,model,product;
String[] phoneInfo;
int[] phoneLocationInfo;    

public String[] getHandsetInfo()
{
    manufacturer = Build.MANUFACTURER;
    model = Build.MODEL;
    product = Build.PRODUCT;
    imei=tm.getDeviceId();        

    String softwareVersion = tm.getDeviceSoftwareVersion();

    phoneInfo = new String[5];
    phoneInfo[0]=imei;
    phoneInfo[1]=product;
    phoneInfo[2]=model;
    phoneInfo[3]=manufacturer;
    phoneInfo[4]=softwareVersion;
    return phoneInfo;

}
public int[] getHandsetLocationInfo()
{
    phoneLocationInfo= new int[4];
    String networkOperator = tm.getNetworkOperator();
     if (networkOperator != null) {
            mcc = Integer.parseInt(networkOperator.substring(0, 3));
            mnc = Integer.parseInt(networkOperator.substring(3));
      }
     CellLocation.requestLocationUpdate(); 
     cellID = location.getCid();
     lac = location.getLac();

     phoneLocationInfo[0]=cellID;
     phoneLocationInfo[1]=lac;
     phoneLocationInfo[2]=mcc;
     phoneLocationInfo[3]=mnc;

     return phoneLocationInfo;

}
}

我想从其他类调用上面的方法并获取这些数组。怎么做，上面的代码是否有任何错误？

Answer 1

假设我们正在谈论Java package，那么我们有几个规则来调用其他包中的类的方法。为了简单起见，这有效：

package com.example.one;
public class ArrayProvider {
  public String[] getArray() {
    return new String{"I'm ","inside ", "an ", "array "};
  }
  public static Object getObject() {
    return new String{"I'm ","inside ", "an ", "array "};
  }
}

现在您的代码可以从其他包中访问类ArrayProvider的方法：

package my.namespace.app;
import com.example.one.ArrayProvider;      // import the other class

public class MyClass {

  public static void main(String[] args) {

    // to access the static method
    Object result1 = ArrayProvider.getObject(); 

    // to access "the other" method
    ArrayProvider provider = new ArrayProvider();
    String[] result2 = provider.getArray();
  }
}

进一步阅读

The Java Tutorial（您的问题针对基本的Java知识）

Answer 2

只需导入其他包并实例化B类并调用该函数。

package Package1;
import Package2;
Class A {
    void callClassBFunction(){
        B b = new B();  //In Package 1 we are instantiating B, however the reference is missing, it should be B b = new B();
        b.callFunction();
}
package Package2;
public class B { //class B should be public
    Object callFunction(){
        //do something and return object
    }
}

如何调用其他包下保存的类的方法

2 个答案: