Question

我正在尝试在我的Windows视图中设置进度状态，但每次运行我的应用时都会导致错误

package example.asynctaskdemo;

import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.Window;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.util.ArrayList;


public class asynctaskdemo extends ActionBarActivity {
    private ListView mainList;

    private String[] texts = {"1", "2", "3", "4", "5", "6", "7", "8", "9", "10",
    "11", "12", "13", "14"};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_PROGRESS);
        setContentView(R.layout.activity_asynctaskdemo);
        mainList = (ListView)findViewById(R.id.my_list);
        mainList.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, new ArrayList<String>()));

        new myAsync().execute();
    }

    class myAsync extends AsyncTask<Void, String, Void>{
        private ArrayAdapter<String> adapter;
        private int counter = 0;
        @Override
        protected void onPreExecute() {
            adapter = (ArrayAdapter<String>)mainList.getAdapter();
            setProgressBarIndeterminate(false);
            setProgressBarVisibility(true);
        }

        @Override
        protected Void doInBackground(Void... params) {

            for(String item: texts){
                publishProgress(item);
                try {
                    Thread.sleep(2000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            return null;
        }

        @Override
        protected void onProgressUpdate(String... values) {
            adapter.add(values[0]);
            counter++;
            setProgress((int)(((double)counter/texts.length)*10000));
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            setProgressBarVisibility(false);
            Debug_It.s(asynctaskdemo.this, "Task has run successfully");
        }
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_asynctaskdemo, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

ERROR：

03-31 19:34:18.960    1058-1058/example.asynctaskdemo E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: example.asynctaskdemo, PID: 1058
    java.lang.RuntimeException: Unable to start activity ComponentInfo{example.asynctaskdemo/example.asynctaskdemo.asynctaskdemo}: android.util.AndroidRuntimeException: requestFeature() must be called before adding content
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)

编译器还建议我使用supportRequestWindowFeature();所以我需要帮助解决此错误，我也想知道supportRequestWindowFeature()和requestWindowFeature();

之间的区别

Answer 1

使用requestWindowFeature(Window.FEATURE_PROGRESS);

之前super.onCreate(savedInstanceState);

它会起作用。即使我也遇到了这个问题。

Answer 2

正如我所看到的，它已经在setContentView之前被调用，所以问题不在于此。

您可能正在使用支持库而不是requestWindowFeature()。您需要使用supportRequestWindowFeature()。这将消除崩溃，但进度条仍然无法显示。

android requestWindowFeature（Window.FEATURE_PROGRESS）错误

2 个答案: