frida之HOOK篇（二）手动hook

frida环境配置请看上一篇

一、编写测试用APP

创建一个button、一个textview 加入以下代码

package com.example.helloworld;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final TextView textView = (TextView) findViewById(R.id.text);
        Button bt = (Button) findViewById(R.id.button);
        bt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                textView.setText(testFrida());
            }
        });
    }

    public String testFrida(){
        String str = "Source String!";
        return str;
    }
}