{"id":22986,"date":"2022-11-22T22:50:14","date_gmt":"2022-11-22T17:20:14","guid":{"rendered":"https:\/\/jassweb.com\/solved\/solved-c-how-to-read-all-the-data-in-a-datagridview-and-put-it-in-a-listbox\/"},"modified":"2022-11-22T22:50:14","modified_gmt":"2022-11-22T17:20:14","slug":"solved-c-how-to-read-all-the-data-in-a-datagridview-and-put-it-in-a-listbox","status":"publish","type":"post","link":"https:\/\/jassweb.com\/solved\/solved-c-how-to-read-all-the-data-in-a-datagridview-and-put-it-in-a-listbox\/","title":{"rendered":"[Solved] C# How to read all the data in a datagridview and put it in a listbox?"},"content":{"rendered":"

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I get the following error: “Object reference not set to an instance of an object”<\/p>\n

The exception is throwing at the “string data” line.<\/p>\n<\/blockquote>\n

I guess one of the values in your DataGridView<\/code> has the value null<\/code>. When you try to call the ToString()<\/code> method on the property Value<\/code> in:<\/p>\n

string data = dgvOverzicht.Rows[getal - 1].Cells[i].Value.ToString();\n<\/code><\/pre>\n
it throws the exception.<\/p>\n
One way to work around this is to check whether Value<\/code> is null<\/code> and if not then go ahead and call the ToString()<\/code> method:<\/p>\n
int getal = 0;\n\nfor (int i = 1; i < 10; i++)\n{\n    getal++;\n    DataGridViewCell  c = dgvOverzicht.Rows[getal - 1].Cells[i];\n    if (c.Value != null)\n    {\n        listBox1.Items.Add(c.Value.ToString());\n    }\n}\n<\/code><\/pre>\n
EDIT:<\/strong><\/p>\n
The for loop that you use will only visit the diagonal of your grid. If you want to get all Cells you need 2 for-loops:<\/p>\n
for (int i = 0; i < dataGridView1.Rows.Count; i++)\n{\n    for (int j = 0; j < dataGridView1.Columns.Count; j++)\n    {\n        DataGridViewCell c = dataGridView1.Rows[i].Cells[j];\n        if (c.Value != null)\n        {\n            listBox1.Items.Add(c.Value.ToString());\n        }\n    }                \n}\n<\/code><\/pre>\n<\/p><\/div>\n
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            12<\/span> <\/p><\/div>\n<\/div>\n
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solved C# How to read all the data in a datagridview and put it in a listbox? <\/p>\n","protected":false},"excerpt":{"rendered":"
[ad_1] I get the following error: “Object reference not set to an instance of an object” The exception is throwing at the “string data” line. I guess one of the values in your DataGridView has the value null. When you try to call the ToString() method on the property Value in: string data = dgvOverzicht.Rows[getal … Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[320],"tags":[324],"class_list":["post-22986","post","type-post","status-publish","format-standard","hentry","category-solved","tag-c"],"yoast_head":"\n[Solved] C# How to read all the data in a datagridview and put it in a listbox? - JassWeb<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/jassweb.com\/solved\/solved-c-how-to-read-all-the-data-in-a-datagridview-and-put-it-in-a-listbox\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"[Solved] C# How to read all the data in a datagridview and put it in a listbox? - JassWeb\" \/>\n<meta property=\"og:description\" content=\"[ad_1] I get the following error: “Object reference not set to an instance of an object” The exception is throwing at the “string data” line. I guess one of the values in your DataGridView has the value null. When you try to call the ToString() method on the property Value in: string data = dgvOverzicht.Rows[getal ... 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