fragment+viewpager学习二（fragment间的跳转） 更新中

Fragment越来越多的被开发者使用，估计即将成为一种趋势。最近被很多人问关于fragment的跳转问题，再加上本人也研究了很多fragment的用法，看了关于fragment的大部分API，特在此说下本人的菜鸟看法

实现一:简单的从一个fragment中跳转到另一个fragment，按返回键返回上一个fragment

1、实现效果图

项目结构图

MainActivity.java

package com.xwj.fragmenttest1;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;

public class MainActivity extends FragmentActivity {

	private FragmentManager fragmentManager;
	private FragmentTransaction fragmentTransaction;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		fragmentManager = getSupportFragmentManager();
		fragmentTransaction = fragmentManager.beginTransaction();

		FragmentTest1 fragmentTest1 = new FragmentTest1();

		fragmentTransaction.replace(R.id.fragment_main, fragmentTest1,
				"fragmentTest1");

		fragmentTransaction.commit();
	}

	@Override
	public void onBackPressed() {
		if (fragmentManager.findFragmentByTag("fragmentTest1") != null
				&& fragmentManager.findFragmentByTag("fragmentTest1")
						.isVisible()) {
			System.out.println("12");
			MainActivity.this.finish();
		} else {
			super.onBackPressed();
		}

	}

}

注：FragmentActivity的FragmentManager是处理Fragment Transaction的而不是处理Fragment

FragmentTransaction默认并不会主动被加入到BackStack中，需要调用addToBackStack(String tag)方法。参数'fragmentTest1'作为本次加入BackStack的Transaction的标志

和addToBackStack相对应的接口方法是popBackStack()和popBackStackImmediate()

FragmentTest1.java

package com.xwj.fragmenttest1;

import android.app.Activity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;

public class FragmentTest1 extends android.support.v4.app.Fragment {

	private static final String TAG = "FragmentTest1---------";

	@Override
	public void onCreate(Bundle savedInstanceState) {
		System.out.println(TAG + "onCreate");
		super.onCreate(savedInstanceState);
	}

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {
		System.out.println(TAG + "onCreateView");
		View view = inflater.inflate(R.layout.test1_fragment, null);
		Button jumpBtn = (Button) view.findViewById(R.id.btn_jump);
		jumpBtn.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				getActivity()
						.getSupportFragmentManager()
						.beginTransaction()
						.replace(R.id.fragment_main, new Fragmenttest2(),
								"Fragmenttest2")
						.addToBackStack("Fragmenttest2").commit();

			}
		});
		return view;

	}

	@Override
	public void onActivityCreated(Bundle savedInstanceState) {
		System.out.println(TAG + "onActivityCreated");
		super.onActivityCreated(savedInstanceState);

	}

	@Override
	public void onAttach(Activity activity) {
		System.out.println(TAG + "onAttach");
		super.onAttach(activity);
	}

	@Override
	public void onDestroy() {
		System.out.println(TAG + "onDestroy");
		super.onDestroy();
	}

	@Override
	public void onDestroyView() {
		System.out.println(TAG + "onDestroyView");
		super.onDestroyView();
	}

	@Override
	public void onPause() {
		System.out.println(TAG + "onPause");
		super.onPause();
	}

	@Override
	public void onResume() {
		System.out.println(TAG + "onResume");
		super.onResume();
	}

	@Override
	public void onStart() {
		System.out.println(TAG + "onStart");
		super.onStart();
	}

	@Override
	public void onStop() {
		System.out.println(TAG + "onStop");
		super.onStop();
	}

	@Override
	public void onDetach() {
		System.out.println(TAG + "onDetach");
		super.onDetach();
	}

}

Fragmenttest1中的

.addToBackStack("Fragmenttest2")

记得一定要添加，这是进栈，方便你从Fragmenttest2中返回时不至于退出程序

至于Fragmenttest2只是简单的界面，在此就不贴出来了

源码下载：点击

下面举例说明Transaction BackStack的进栈和出栈

如下图，使用FragmentActivity的FragmentManager创建Trasaction1并提交，使页面显示AFragment。这时调用popBackStack()就会移除AFragment并返回FragmentActivity。

 @Override
 public void addFragment(BaseFragment baseFragment) {
     FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
     ft.replace(R.id.home_frame_layout_for_fragments, baseFragment, baseFragment.getTagText());
     ft.addToBackStack(baseFragment.getTagText());
     ft.commit();
 }

在AFragment已经在栈顶的情况下，我们再创建Transation2并提交，Transaction 2添加了两个Fragment，提交后页面显示的是CFragment，这时调用popBackStack()就会将Transaction2从BackStack移除，即将CFragment和BFragment同时移除，页面将显示AFragment。

 @Override
 public void addMultipleFragments(BaseFragment[] baseFragments) {
     FragmentTransaction ft = getSupportFragmentManager().beginTransaction();

     for(int i = 0 ; i < baseFragments.length ; i++) {
         ft.replace(R.id.home_frame_layout_for_fragments, baseFragments[i], baseFragments[i].getTagText());
     }
     ft.addToBackStack(baseFragments[0].getTagText());
     ft.commit();
 }

参考资料：