记一次内存泄露优化

前言

dialog引起的内存泄露

最近在优化项目发现好几个地方出现了内存泄露

我封装了一个TipDialog，用在网络请求时候显示，请求结束时消息。上代码：

    private void initDialog(Activity activity) {

        dialog = (TipDialog) new TipDialog(activity)
                .build()
                .setTipText("正在加载")
                .setIconId(R.drawable.icon_load)
                .setOrientationHorizontal(false)
                .setIsLoading(true)
                .show();

    }

    public DialogCallback(Activity activity) {
        super();
        initDialog(activity);
    }

    @Override
    public void onStart(Request<T, ? extends Request> request) {
        super.onStart(request);
    }

    @Override
    public void onFinish() {
        //网络请求结束后关闭对话框
        if (dialog != null ) {
            dialog.dismissDialog();
        }
        
    }

TipDialog:

package com.yeqiu.hydrautils.view.dialog;

import android.animation.ObjectAnimator;
import android.app.Activity;
import android.content.DialogInterface;
import android.support.v4.content.ContextCompat;
import android.text.TextUtils;
import android.view.Gravity;
import android.view.View;
import android.view.WindowManager;
import android.view.animation.LinearInterpolator;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;

import com.yeqiu.hydrautils.R;
import com.yeqiu.hydrautils.common.DensityUtils;
import com.yeqiu.hydrautils.ui.widget.marquee.MarqueeTextView;
import com.yeqiu.hydrautils.view.dialog.base.BaseDialog;

/**
 * @project：HailHydra
 * @author：小卷子
 * @date 2018/9/10
 * @describe：
 * @fix：
 */
public class TipDialog extends BaseDialog {

    private ObjectAnimator animator;
    private ImageView imageView;
    private LinearLayout llRoot;

    public TipDialog(Activity context) {
        super(context);
    }


    @Override
    protected int getstyle() {

        return R.style.TipDialog;
    }

    @Override
    protected Object getDiaologlayoutIdOrView() {

        return R.layout.layout_tip_dialog;
    }

    @Override
    protected void initView(View view) {

        llRoot = (LinearLayout) view.findViewById(R.id.ll_tip_dialog_root);
        if (dialogBuilder.getOrientationHorizontal()) {
            llRoot.setOrientation(LinearLayout.HORIZONTAL);
            RelativeLayout.LayoutParams rootLayoutParams = (RelativeLayout.LayoutParams) llRoot
                    .getLayoutParams();
            rootLayoutParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
            rootLayoutParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
            llRoot.setLayoutParams(rootLayoutParams);

        } else {
            llRoot.setOrientation(LinearLayout.VERTICAL);
            RelativeLayout.LayoutParams rootLayoutParams = (RelativeLayout.LayoutParams) llRoot
                    .getLayoutParams();
            rootLayoutParams.width = DensityUtils.dp2px(100);
            rootLayoutParams.height = DensityUtils.dp2px(100);
            llRoot.setLayoutParams(rootLayoutParams);
        }
        if (dialogBuilder.getIconId() != -999) {
            imageView = new ImageView(context);
            LinearLayout.LayoutParams imageViewLP = new LinearLayout.LayoutParams(DensityUtils
                    .dp2px(30), DensityUtils.dp2px(30));
            imageView.setLayoutParams(imageViewLP);
            imageView.setImageResource(dialogBuilder.getIconId());
            llRoot.addView(imageView);
        }
        if (!TextUtils.isEmpty(dialogBuilder.getTipText())) {
            MarqueeTextView textView = new MarqueeTextView(context);
            LinearLayout.LayoutParams tipViewLP = new LinearLayout.LayoutParams(LinearLayout
                    .LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
            //垂直布局
            tipViewLP.topMargin = dialogBuilder.getOrientationHorizontal() ? 0 : DensityUtils.dp2px(10);

            //水平布局
            tipViewLP.leftMargin = dialogBuilder.getOrientationHorizontal() ? DensityUtils.dp2px  (10) : 0;
            textView.setLayoutParams(tipViewLP);
            textView.setEllipsize(TextUtils.TruncateAt.MARQUEE);
            textView.setSingleLine();
            textView.setGravity(Gravity.CENTER);
            textView.setTextColor(ContextCompat.getColor(context, R.color.color_white));
            textView.setTextSize(14);
            textView.setText(dialogBuilder.getTipText());

            llRoot.addView(textView);
        }

    }

    public void startAnimate() {

        if (imageView != null) {
            animator = ObjectAnimator.ofFloat(imageView, "rotation",
                    0f, 360f);
            animator.setDuration(1000);
            animator.setInterpolator(new LinearInterpolator());
            animator.setRepeatCount(ObjectAnimator.INFINITE);
            animator.setRepeatMode(ObjectAnimator.RESTART);
        }
        animator.start();

    }


    @Override
    public void show() {

        if (context == null || context.isFinishing()) {
            return;
        }

        super.show();

        if (dialogBuilder.isLoading()) {
            startAnimate();
        }

        int dismissTime = dialogBuilder.getDismissTime();

        if (dismissTime != 0 && llRoot != null) {
            llRoot.postDelayed(new Runnable() {
                @Override
                public void run() {
                    dismiss();
                }
            }, dismissTime);
        }


        dialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
            @Override
            public void onDismiss(DialogInterface dialog) {
                if (animator != null) {
                    animator.end();
                }
            }
        });
    }

    public void dismiss() {
        if (dialog != null && context != null && !context.isFinishing()) {
            dialog.dismiss();
        }
    }
}

泄露的信息：

img

看上去似乎没问题，但是在我快速进入退出页面的时候，leakcanary就报出了泄露的地方，TipDialog.context。提示消息很好理解，当页面消失的时候 TipDialog持有了context，这里的context就是当前Activity。TipDialog没有销毁导致Activity无法回收。

知道问题就开始分析，我想在dialog消失或者网络请求结束的时候把context置为null。再次运行，并没有效果。猜想可能是我封装的dialog有问题，仔细检查好像似乎并没有问题。我尝试用系统的ProgressDialog。

private void initDialog(Activity activity) {
        dialog = new ProgressDialog(activity);
        dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
        dialog.setCanceledOnTouchOutside(false);
        dialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
        dialog.setMessage("请求网络中...");
    }

    public DialogCallback(Activity activity) {
        super();
        initDialog(activity);
    }

    @Override
    public void onStart(Request<T, ? extends Request> request) {
        if (dialog != null && !dialog.isShowing()) {
            dialog.show();
        }
    }

    @Override
    public void onFinish() {
        //网络请求结束后关闭对话框
        if (dialog != null && dialog.isShowing()) {
            dialog.dismiss();
        }
    }

点击运行，嗯 果然没有泄露。继续看泄露信息，message.obj 这个似乎好像是和Handler有关。可是我的代码里都没有用过Handler。最后在网上看到一篇博文介绍了dialog监听的实现方式。系统内部通过Handler来回调事件。博文里使用的是 DialogInterface.OnClickListener()造成内存泄露，最后的解决办法是做了一个包裹类，在dialog消失的时把 DialogInterface.OnClickListener()置为null。分析一波后就知道我这里泄露的原因，因为我设置dialog消失的监听，在消失后停止转圈的动画。

 dialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
            @Override
            public void onDismiss(DialogInterface dialog) {
                if (animator != null) {
                    animator.end();
                }
            }
        });
    }

我尝试在dialog的onDismiss监听里把OnDismissListener置为null，但是还是没有解决。这里贴出我最后的解决办法

    public void clearOnDetach(final Dialog dialog) {

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
            dialog.getWindow()
                    .getDecorView()
                    .getViewTreeObserver()
                    .addOnWindowAttachListener(new ViewTreeObserver.OnWindowAttachListener() {
                        @Override
                        public void onWindowAttached() {
                        }

                        @Override
                        public void onWindowDetached() {

                            onDialogDismiss();
                            
                        }
                    });
        }

    }

    protected void onDialogDismiss() {
        if (dialogBuilder.getDialogListener() != null) {
            dialogBuilder.getDialogListener().onDialogDismiss();
        }

    }

这里不再设置dialog消失的监听，但是对dialog的window做了脱离视图的监听。重新测试，没有在出现泄漏。代码已经加入HailHydr豪华午餐。

相关资料：

一个内存泄漏引发的血案-Square

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