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

解决Android应用中创建Dialog时的错误问题

最新推荐文章于 2021-04-30 16:03:35 发布

原创最新推荐文章于 2021-04-30 16:03:35 发布 · 92 阅读

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本文探讨了在Android应用开发中遇到的创建Dialog时出现的错误：Unable to add window -- token null is not for an application。通过调整Context的引用方式，从getApplicationContext()更改为Activity.this，成功解决了问题。文章详细介绍了错误原因及解决步骤，为开发者提供了实用的解决方案。

转于：http://blog.youkuaiyun.com/wsz1z154/article/details/7724912

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在创建一个Dialog时，发生的错误：

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

[java]view plaincopy
      
    
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