Question

我编写了一个读取文本文件的程序，检查第一个元素是否为1并将其显示到textview（TextViewDisk1）并检查它是否为2等等。它确实运行良好但仅适用于第一行。程序读完下一行后，应用停止。

logcat的

android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views。

如何解决这个问题？

代码

 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //Read text file and show number on the textview
    new Thread(new Runnable() {
        @Override
        public void run() {

            final TextView TextDisk1 = (TextView) findViewById(R.id.TextDisk1);
            final TextView TextDisk2 = (TextView) findViewById(R.id.TextDisk2);
            final TextView TextDisk3 = (TextView) findViewById(R.id.TextDisk3);
            final TextView TextDisk4 = (TextView) findViewById(R.id.TextDisk4);
            final TextView TextDisk5 = (TextView) findViewById(R.id.TextDisk5);
                try {
                    InputStream stream = getAssets().open("Messwerte.txt");
                    InputStreamReader reader = new InputStreamReader(stream);
                    BufferedReader buffer = new BufferedReader(reader);
                    String lines;
                    for (int i = 0; i < 2400; i++) {

                        lines = buffer.readLine();
                        String[] line = lines.split("\t");
                        String first = line[0];
                        String second = line[1];
                        String third = line[2];
                        TextDisk3.setText(third);
                        if(first.equals("1"))
                        {
                            TextDisk1.setText(second);
                        }

                        else if(first.equals("2"))
                        {
                            TextDisk2.setText(second);
                        }
                        else if(first.equals("4"))
                        {
                            TextDisk4.setText(second);
                        }

                        else if(first.equals("5"))
                        {
                            TextDisk5.setText(second);
                        }

                        i++;
                        Thread.sleep(6000);
                    }

                } catch (IOException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
        }

    }).start();

Answer 1

如果你想从一个不需要使用runOnuiThread（..）的ui线程的线程修改textview。这是一个例子。

new Thread(new Runnable() {
            @Override
            public void run() {

                final TextView TextDisk1 = (TextView) findViewById(R.id.TextDisk1);
                final TextView TextDisk2 = (TextView) findViewById(R.id.TextDisk2);
                final TextView TextDisk3 = (TextView) findViewById(R.id.TextDisk3);
                final TextView TextDisk4 = (TextView) findViewById(R.id.TextDisk4);
                final TextView TextDisk5 = (TextView) findViewById(R.id.TextDisk5);
                try {
                    InputStream stream = getAssets().open("Messwerte.txt");
                    InputStreamReader reader = new InputStreamReader(stream);
                    BufferedReader buffer = new BufferedReader(reader);
                    String lines;
                    for (int i = 0; i < 2400; i++) {

                        lines = buffer.readLine();
                        String[] line = lines.split("\t");
                        String first = line[0];
                        String second = line[1];
                        String third = line[2];
                        WriteText(TextDisk3, third);
                        if (first.equals("1")) {
                            WriteText(TextDisk1, second);
                        }

                        else if (first.equals("2")) {
                            WriteText(TextDisk2, second);
                        } else if (first.equals("4")) {
                            WriteText(TextDisk4, second);

                        }

                        else if (first.equals("5")) {
                            WriteText(TextDisk5, second);

                        }

                        i++;
                        Thread.sleep(6000);
                    }

                } catch (IOException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }

        }).start();
    }

    public void WriteText(final TextView textview, final String value) {
        runOnUiThread(new Runnable() {

            @Override
            public void run() {
                textview.setText(value);
            }
        });
    }
}

如果您的文件不是2400行，则会抛出nullPointerException。

读取文本文件并逐行将其添加到多个文本视图中

1 个答案: