使用Xposed 风格的api hook自身app的类无效

[KuNgia09]

测试环境:
小米10 Android 11
pine使用的最新版本
implementation 'top.canyie.pine:core:0.2.9'
implementation 'top.canyie.pine:xposed:0.1.0'

使用Pine 风格api hook sum函数可以hook

 private void hookSumByPineStyle(ClassLoader loader){
        Class mainActivity = XposedHelpers.findClass("org.fengyue.targetapk.MainActivity", loader);
        try {
            if (mainActivity != null) {
                Method mid = mainActivity.getDeclaredMethod("sum", int.class, int.class);
                if (mid != null) {
                    MethodHook.Unhook unhook = Pine.hook(mid, new MethodHook() {
                        @Override
                        public void beforeCall(Pine.CallFrame callFrame) throws Throwable {
                            super.beforeCall(callFrame);
                            int a = (int) callFrame.args[0];
                            int b = (int) callFrame.args[1];
                            Log.d(TAG, "hook MainActivity sum method a:" + a + ";b:" + b);
                        }

                        @Override
                        public void afterCall(Pine.CallFrame callFrame) throws Throwable {
                            super.afterCall(callFrame);
                            callFrame.setResult(1000);
                        }
                    });
                    Log.d(TAG, "hook MainActivity success");

                }
            }
        } catch (NoSuchMethodException e) {
            throw new RuntimeException(e);
        }
    }

使用xposed风格 hook不生效

private void hookSumByXposedStyle(ClassLoader loader) {
       Class mainActivity=XposedHelpers.findClass("org.fengyue.targetapk.MainActivity",loader);
       XC_MethodHook.Unhook unhook = XposedHelpers.findAndHookMethod(mainActivity, "sum", int.class, int.class, new XC_MethodHook() {
           @Override
           protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
           }
           @Override
           protected void afterHookedMethod(MethodHookParam param) throws Throwable {

               Log.d(TAG, "get sum original result:" + (String) param.getResult());

               param.setResult(20000);
           }
       });
       if (unhook != null) {
           Log.d(TAG, "hook MainActiivty sum method success");
       } else {
           Log.e(TAG, "hook MainActiivty sum method failed");
       }

   }

[canyie]

           protected void afterHookedMethod(MethodHookParam param) throws Throwable {

               Log.d(TAG, "get sum original result:" + (String) param.getResult());

               param.setResult(20000);
           }

你的打 log 的那行代码把原方法返回的结果强制转换成了 String，从你的代码来看该方法返回的结果应该是个整数，这里会触发一个 ClassCastException 导致执行被中断，所以底下的 setResult 没有实际调用到。
这个问题只要看一眼 log 就能看见的……

[KuNgia09]

Thanks