Activity通过Argument向Fragment传递数据

今天又学了Activity通过Argument向Fragment传递数据，这种方式是安卓给我们提供的，相比与用方法传递，它能传递更多的数据，更加常用。

Argument传递数据需要使用Bundle容器，传递的实际上是键值对，形式上有点类似intent和servlet里的session。

代码实现：

package com.example.dataapplication;

import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;

import android.os.Bundle;
import android.view.View;

import com.example.dataapplication.fragment.BlankFragment1;
import com.example.dataapplication.fragment.BlankFragment2;

public class DynamicFragmentActivity extends AppCompatActivity {

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

        getSupportFragmentManager()
                .beginTransaction()
                .replace(R.id.frag_dy_1,BlankFragment2.class, null)
                .commit();

    }

    
    public void ArgumentDataClick(View view) {
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction fragmentTransaction =  fragmentManager.beginTransaction();
        BlankFragment2 blankFragment2 = new BlankFragment2();
        Bundle bundle = new Bundle();
        bundle.putString("data","这是通过Argument传递的数据");
        bundle.putInt("int_data",168);
        blankFragment2.setArguments(bundle);
        fragmentTransaction.replace(R.id.frag_dy_1,blankFragment2).commit();
    }
}

我们需要在fragment 中创建全局变量，

然后重写onCreate方法 

data = getArguments().getString("data");

然后onViewCreated加入

if (!TextUtils.isEmpty(data)){
            mTextView.setText(data+int_data);
        }

用于给textview赋值

package com.example.dataapplication.fragment;

import android.os.Bundle;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.example.dataapplication.R;

public class BlankFragment2 extends Fragment {
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";
    private String mParam1;
    private String mParam2;
    private String data;
    private int int_data;
    private TextView mTextView;
    public BlankFragment2(String data) {
        mParam1 = data;
    }
    public BlankFragment2() {
    }
    public void setArgParam1(String data){
        this.mParam1 = data;
        if (!TextUtils.isEmpty(mParam1)){
            mTextView.setText(mParam1);
        }
    }
    public static BlankFragment2 newInstance(String param1, String param2) {
        BlankFragment2 fragment = new BlankFragment2();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);

            data = getArguments().getString("data");
            int_data   = getArguments().getInt("int_data");

        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_blank2, container, false);
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        mTextView = view.findViewById(R.id.item_frag1);
        if (!TextUtils.isEmpty(mParam1)){
            mTextView.setText(mParam1);
        }
        if (!TextUtils.isEmpty(data)){
            mTextView.setText(data+int_data);
        }
    }
}