警报对话框未显示

Lal*_*tar 6 alert android dialog

大家好我只是通过点击一个按钮在android中创建一个警告对话框.我使用了XML的onClick属性并调用了函数.我的代码是

public void selectPhoneType(View view)
{
    String [] item = {"Home", "Work", "Mobile", "Work Fax", "Home Fax", "Pager", "Other", "Custom"};
    AlertDialog.Builder builder = new AlertDialog.Builder(getApplicationContext());
    builder.setTitle("Select Label");
    AlertDialog alert = builder.create();
    alert.show();}
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但是这段代码没有显示警告并且给出了错误

BadTokenException: Unable to add window -- token null is not for an application. 
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请告诉我这段代码有什么问题.

Not*_*Man 21

new AlertDialog.Builder(getApplicationContext());
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我认为这是问题所在.你有没有尝试过:

new AlertDialog.Builder(YourActivityClassName.this);
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