解析xml android Android源代码解析之（十三）(8)

经过一些view的初始化操作之后调用了doPackageStage方法，该方法主要是通过调用PackageInstaller运行apk文件的安装，这里就不在详细的介绍了，在apk文件安装完毕之后PackageInstaller会发送一个安装完毕的广播。刚刚我们在onCreate方法中注册了一个广播。其能够用来接收apk安装完毕的广播：

private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            final int statusCode = intent.getIntExtra(
                    PackageInstaller.EXTRA_STATUS, PackageInstaller.STATUS_FAILURE);
            if (statusCode == PackageInstaller.STATUS_PENDING_USER_ACTION) {
                context.startActivity((Intent)intent.getParcelableExtra(Intent.EXTRA_INTENT));
            } else {
                onPackageInstalled(statusCode);
            }
        }
    };

这样apk安装完毕之后，这里的广播会接收到广播并运行onPackageInstalled方法，运行兴许的处理逻辑，那么我们来看一下onPackageInstalled方法的详细实现逻辑：

void onPackageInstalled(int statusCode) {
        Message msg = mHandler.obtainMessage(INSTALL_COMPLETE);
        msg.arg1 = statusCode;
        mHandler.sendMessage(msg);
    }

好吧。这里是发送Handler异步消息，我们来看一下异步消息的处理逻辑：

private Handler mHandler = new Handler() {
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case INSTALL_COMPLETE:
                    mInstallFlowAnalytics.setFlowFinishedWithPackageManagerResult(msg.arg1);
                    if (getIntent().getBooleanExtra(Intent.EXTRA_RETURN_RESULT, false)) {
                        Intent result = new Intent();
                        result.putExtra(Intent.EXTRA_INSTALL_RESULT, msg.arg1);
                        setResult(msg.arg1 == PackageInstaller.STATUS_SUCCESS
                                ? Activity.RESULT_OK : Activity.RESULT_FIRST_USER,
                                        result);
                        finish();
                        return;
                    }
                    // Update the status text
                    mProgressBar.setVisibility(View.INVISIBLE);
                    // Show the ok button
                    int centerTextLabel;
                    int centerExplanationLabel = -1;
                    LevelListDrawable centerTextDrawable =
                            (LevelListDrawable) getDrawable(R.drawable.ic_result_status);
                    if (msg.arg1 == PackageInstaller.STATUS_SUCCESS) {
                        mLaunchButton.setVisibility(View.VISIBLE);
                        centerTextDrawable.setLevel(0);
                        centerTextLabel = R.string.install_done;
                        // Enable or disable launch button
                        mLaunchIntent = getPackageManager().getLaunchIntentForPackage(
                                mAppInfo.packageName);
                        boolean enabled = false;
                        if(mLaunchIntent != null) {
                            List<ResolveInfo> list = getPackageManager().
                                    queryIntentActivities(mLaunchIntent, 0);
                            if (list != null && list.size() > 0) {
                                enabled = true;
                            }
                        }
                        if (enabled) {
                            mLaunchButton.setOnClickListener(InstallAppProgress.this);
                        } else {
                            mLaunchButton.setEnabled(false);
                        }
                    } else if (msg.arg1 == PackageInstaller.STATUS_FAILURE_STORAGE){
                        showDialogInner(DLG_OUT_OF_SPACE);
                        return;
                    } else {
                        // Generic error handling for all other error codes.
                        centerTextDrawable.setLevel(1);
                        centerExplanationLabel = getExplanationFromErrorCode(msg.arg1);
                        centerTextLabel = R.string.install_failed;
                        mLaunchButton.setVisibility(View.INVISIBLE);
                    }
                    if (centerTextDrawable != null) {
                    centerTextDrawable.setBounds(0, 0,
                            centerTextDrawable.getIntrinsicWidth(),
                            centerTextDrawable.getIntrinsicHeight());
                        mStatusTextView.setCompoundDrawablesRelative(centerTextDrawable, null,
                                null, null);
                    }
                    mStatusTextView.setText(centerTextLabel);
                    if (centerExplanationLabel != -1) {
                        mExplanationTextView.setText(centerExplanationLabel);
                        mExplanationTextView.setVisibility(View.VISIBLE);
                    } else {
                        mExplanationTextView.setVisibility(View.GONE);
                    }
                    mDoneButton.setOnClickListener(InstallAppProgress.this);
                    mOkPanel.setVisibility(View.VISIBLE);
                    break;
                default:
                    break;
            }
        }
    };

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