Question

大家好我想在短暂延迟后尝试更新UI，为此我正在使用处理程序的postdelayed方法。以下代码最初将我的textview文本设置为“Processing”，并且处理程序的runnable中包含的代码会被执行，但不会更新UI？请注意，这是在片段中完成的

TextView progressText=(TextView)parent.findViewById(R.id.inProgressText);
progressText.setText("Processing");

getActivity().getMainLooper()).postDelayed(new Runnable() {
    @Override
    public void run() {
        TextView progressText=(TextView)parent.findViewById(R.id.inProgressText);
        progressText.setText("Request completed");              
    }
}, 3000);

感谢您的帮助

Answer 1

更改

getActivity().getMainLooper()).postDelayed(new Runnable()

为：

final Handler handler = new Handler();

然后

handler.postDelayed(new Runnable() {
    @Override
    public void run() {
        final TextView progressText=(TextView)findViewById(R.id.inProgressText);
        progressText.setText("Request completed");              
    }
}, 3000);

Answer 2

使用此代码

public class MainActivity extends Activity {
TextView progressText = null;

public View onCreateView(LayoutInflater inflater, ViewGroup container,
    Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.activity_main, container, false);

    progressText = (TextView) rootView.findViewById(R.id.inProgressText);
    progressText.setText("Processing");
    progressText.postDelayed(new Runnable() {
        @Override
        public void run() {
            progressText.setText("Request completed");
        }
    }, 3000);
       return rootView;
}
}

Answer 3

请尝试这种方式：我检查了Fragment，它运行正常。

View parent= inflater.inflate(R.layout.your_fragement, container, false);
TextView progressText=(TextView)parent.findViewById(R.id.inProgressText);
progressText.setText("Processing");

            progressText.postDelayed(new Runnable() {
                @Override
                public void run() {
                    progressText.setText("Request completed");
                }
            }, 3000);

处理程序postDelayed无法更新UI

3 个答案: