Unable to add window -- token null is not for an application

最新推荐文章于 2019-11-26 10:17:04 发布

转载最新推荐文章于 2019-11-26 10:17:04 发布 · 689 阅读

本文解决了一个在创建Dialog时遇到的错误：Unable to add window -- token null is not for an application。通过将Context改为Activity.this，成功解决了问题，并提供了改正后的代码示例。

在创建一个Dialog时，发生的错误：

Unable to add window -- token null is not for an application

        AlertDialog.Builder builder;
        AlertDialog alertDialog;
        Context mContext = getApplicationContext();      
        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(LAYOUT_INFLATER_SERVICE);
        View layout = inflater.inflate(R.layout.custom_dialog, (ViewGroup)findViewById(R.id.layout_root));
    
        TextView text = (TextView) layout.findViewById(R.id.text);
        text.setText("Hello, this is a custom dialog!");
        ImageView image = (ImageView) layout.findViewById(R.id.image);
        image.setImageResource(R.drawable.icon);
        builder = new AlertDialog.Builder(mContext);
        builder.setView(layout);
        alertDialog = builder.create();
        alertDialog.show();

查询SDK帮助文档：

Return the context of the single, global Application object of the current process. This generally should only be used if you need a Context whose lifecycle is separate from the current context, that is tied to the lifetime of the process rather than the current component.

把这句Context mContext = getApplicationContext();

改成Activity.this即可